1
00:00:00,000 --> 00:00:11,330

2
00:00:11,330 --> 00:00:12,360
>> DAVID Malan: Kull dritt.

3
00:00:12,360 --> 00:00:15,970
Dan huwa CS50, u dan huwa
l-aħħar ta 'disa' ġimgħa.

4
00:00:15,970 --> 00:00:18,560
Huwa kien whirlwind fuq
l-aħħar ftit jiem.

5
00:00:18,560 --> 00:00:21,580
U l-problema stabbilita seba ', jekk int irkoppa
fond fis dan, realizzata hemm pjuttost

6
00:00:21,580 --> 00:00:23,340
bit ġdida li fil hemmhekk.

7
00:00:23,340 --> 00:00:26,660
Imma ejja ara jekk aħna ma tistax biċċa
kollox flimkien hawnhekk fil-qosor

8
00:00:26,660 --> 00:00:29,230
qabel dakinhar veering off fil għadhom
Stat direzzjoni u tara

9
00:00:29,230 --> 00:00:30,510
fejn inkella nistgħu mmorru.

10
00:00:30,510 --> 00:00:32,630
>> Allura s'issa, konna tkellimna dwar HTML.

11
00:00:32,630 --> 00:00:33,740
Imxejna tkellem dwar CSS.

12
00:00:33,740 --> 00:00:34,705
Imxejna tkellem dwar PHP.

13
00:00:34,705 --> 00:00:36,520
You ħadthom bdew iġarrbu SQL.

14
00:00:36,520 --> 00:00:38,360
Illum, aħna ser nitkellmu daqsxejn
dwar JavaScript.

15
00:00:38,360 --> 00:00:41,230
Imma kif do kollha ta 'dawn dispari
lingwi joqogħdu flimkien?

16
00:00:41,230 --> 00:00:44,970
>> Allura aħna tkellimna aħħar ġimgħa dwar il-
kunċett ta jkollhom server.

17
00:00:44,970 --> 00:00:48,470
Mela ejja biss jiġbed dan ir-rettangolu
bħala web server hawn.

18
00:00:48,470 --> 00:00:52,200
U web server jservi żgur files.

19
00:00:52,200 --> 00:00:54,640
U xi wħud minn dawk il-fajls
jista 'jkun fajls HTML.

20
00:00:54,640 --> 00:00:58,270
Allura waħda mill-affarijiet li web server
jistgħu bżiq out jista 'jkun fajl li

21
00:00:58,270 --> 00:01:01,290
aħna ser biss jiġbed bħal dan
fihom xi HTML.

22
00:01:01,290 --> 00:01:04,786
Allura f'termini laymans, dak
ma HTML let you do?

23
00:01:04,786 --> 00:01:06,036
>> UDJENZA: Page tfittex sbieħ.

24
00:01:06,036 --> 00:01:09,670

25
00:01:09,670 --> 00:01:12,310
>> DAVID Malan: OK, tagħmel paġna ħarsa sbieħ,
għalkemm I think stajt ippruvati

26
00:01:12,310 --> 00:01:13,370
li mod ieħor.

27
00:01:13,370 --> 00:01:18,250
Allura HTML ma tavżak jistabbilixxu paġni
strutturalment, u li jippermettilek li

28
00:01:18,250 --> 00:01:22,410
tip ta 'estetikament mark up paġna,
mark up kontenut statiku, sabiex inti

29
00:01:22,410 --> 00:01:23,640
jistgħu mbagħad tarah ma 'web browser.

30
00:01:23,640 --> 00:01:24,690
>> Iżda li l-ċavetta.

31
00:01:24,690 --> 00:01:26,130
Huwa kontenut statiku.

32
00:01:26,130 --> 00:01:28,590
Tikteb, inti isalvawh,
u allura inti vapur.

33
00:01:28,590 --> 00:01:31,130
U l-web server imbagħad jservi
it up għall-viżitaturi tiegħek.

34
00:01:31,130 --> 00:01:35,700
>> Iżda aħna stylize affarijiet jużaw differenti
lingwa għal kollox.

35
00:01:35,700 --> 00:01:40,150
Bdejna biex tuża attribut stil
dwar ċerti tags.

36
00:01:40,150 --> 00:01:43,400
U l-attribut istil let us stabbiliti
affarijiet simili daqs tat-tipa u kulur.

37
00:01:43,400 --> 00:01:46,460
U inti probabilment ħadthom bdew jiskopru,
jew inti hekk se għal finali

38
00:01:46,460 --> 00:01:50,160
proġetti potenzjalment, iżda oħrajn
proprjetajiet li tista 'tuża fil-CSS.

39
00:01:50,160 --> 00:01:54,710
U hekk f'termini laymans, dak
verament allura ma CSS tagħmel?

40
00:01:54,710 --> 00:01:57,810
Dawk huma biss eżempji tiegħu.

41
00:01:57,810 --> 00:02:00,730
X'tikkontrolla tavżak tagħmel dan HTML
ma jidhirx li minn dak

42
00:02:00,730 --> 00:02:02,606
Rajna s'issa?

43
00:02:02,606 --> 00:02:04,850
>> UDJENZA: Iddefinixxi stili mill yourself.

44
00:02:04,850 --> 00:02:06,700
>> DAVID Malan: Iddefinixxi stili
mill yourself.

45
00:02:06,700 --> 00:02:10,280
Allura jiddefinixxu affarijiet simili klassijiet kif inti
jistgħu ikunu ltaqgħu magħhom, jew unikament

46
00:02:10,280 --> 00:02:13,800
jidentifikaw nodes 'dokument sabiex
li inti tista stylize lilhom.

47
00:02:13,800 --> 00:02:16,890
Iżda aktar speċifiku, I d ngħid li CSS
verament ihallik jieħdu l-affarijiet l-

48
00:02:16,890 --> 00:02:20,790
aħħar mil u tippermetti li inti tispeċifika ħafna
b'mod aktar preċiż l-estetika,

49
00:02:20,790 --> 00:02:24,340
billi HTML għall-aktar parti tikri
inti istruttura paġni tiegħek.

50
00:02:24,340 --> 00:02:27,310
>> U anki jekk hemm xi nuqqasijiet,
bħall rajna l-tikketta għall-

51
00:02:27,310 --> 00:02:30,690
intestatura tag, li madwar jitkellem
magħmula affarijiet kbir u ambizzjuz.

52
00:02:30,690 --> 00:02:34,250
Li definizzjoni pretty ġeneriku
tal-lametta - kbir u ambizzjuz.

53
00:02:34,250 --> 00:02:35,260
X'inhu d-daqs tat-tipa huwa li?

54
00:02:35,260 --> 00:02:36,080
Liema kulur huwa li?

55
00:02:36,080 --> 00:02:36,890
Kif kuraġġużi huwa li?

56
00:02:36,890 --> 00:02:39,830
U CSS ihallik aktar fin
affarijiet intunazzjoni bħal dik.

57
00:02:39,830 --> 00:02:42,150
Kif ukoll tqassim, kif xi wħud
minnkom raw.

58
00:02:42,150 --> 00:02:45,180
>> U franchement, CSS huwa daqsxejn
ta 'lingwa messy.

59
00:02:45,180 --> 00:02:48,370
Huwa qawwija ħafna li inti tista 'tagħmel
litteralment kwalunkwe websajt li inti ħadthom

60
00:02:48,370 --> 00:02:51,880
jidhru fuq il-web illum magħha, iżda
huwa tip ta 'uġigħ fl-għonq.

61
00:02:51,880 --> 00:02:54,440
U xi wħud minnkom banged ras tiegħek
kontra l-ħitan diġà biss biex jagħmlu

62
00:02:54,440 --> 00:02:58,560
xi ħaġa stupid bħal ċentru menu fuq
problema sett seba jekk inti ħadthom gotten

63
00:02:58,560 --> 00:02:59,470
dak il-punt diġà.

64
00:02:59,470 --> 00:03:01,530
>> Iżda realizzata, dawk l-affarijiet
tikseb aktar faċli maż-żmien.

65
00:03:01,530 --> 00:03:02,820
Tibda l-avviż mudelli.

66
00:03:02,820 --> 00:03:06,020
U għal darb'oħra, Google se tkun ħabib tiegħek
għad-diversi modi li bihom tista '

67
00:03:06,020 --> 00:03:07,220
issolvi dawn it-tipi ta 'problemi.

68
00:03:07,220 --> 00:03:11,520
>> U jien DARE ngħid CSS, HTML u aktar
ġeneralment, inti tista 'ssolvi l-problemi fil-

69
00:03:11,520 --> 00:03:15,910
ħafna aktar modi, li kollha jistgħu ħafna
ukoll tkun korretta, milli inti tista '

70
00:03:15,910 --> 00:03:18,900
fil xi ħaġa simili C, anki
issa PHP, JavaScript jew.

71
00:03:18,900 --> 00:03:21,080
Hemm biss differenti ħafna
modi biex jistabbilixxu affarijiet out.

72
00:03:21,080 --> 00:03:22,570
>> Iżda dan bdiet tikseb
messy, għidna.

73
00:03:22,570 --> 00:03:26,480
Just tip ta 'taħlit HTML tiegħek u
CSS tiegħek mal-attribut istil kien

74
00:03:26,480 --> 00:03:27,590
a sloppy ftit.

75
00:03:27,590 --> 00:03:31,460
U hekk aħna minflok qal, tip ta '
astratt jitkellem, li inti għandek

76
00:03:31,460 --> 00:03:34,050
inqas tibda fattur
out CSS tiegħek probabbilment.

77
00:03:34,050 --> 00:03:37,430
Mhux attributi stil tiegħek, iżda mill-inqas
użu l-tikketta istil ġewwa dak

78
00:03:37,430 --> 00:03:38,840
parti tal-paġna web?

79
00:03:38,840 --> 00:03:39,560
>> UDJENZA: Kap.

80
00:03:39,560 --> 00:03:40,120
>> DAVID Malan: Fir-ras.

81
00:03:40,120 --> 00:03:43,270
Sa issa, aħna biss kellhom it-titolu up
hemm, imma int tista 'wkoll żżid stil

82
00:03:43,270 --> 00:03:47,230
tag, u inti tista 'tpoġġi CSS tiegħek bejn wieħed u ieħor
jitkellem lejn il-quċċata tal-paġna.

83
00:03:47,230 --> 00:03:52,550
Iżda mbagħad aħna ħa l-affarijiet pass ulterjuri
u aħna f'fatturi li taf aktar

84
00:03:52,550 --> 00:03:54,130
fis-fajl separat.

85
00:03:54,130 --> 00:03:57,240
>> U hekk dawn iż-żewġ fajls kienu
b'xi issa marbuta.

86
00:03:57,240 --> 00:03:59,550
U fil-fatt kien il-
tag li ma li.

87
00:03:59,550 --> 00:04:02,920
U dak kien wieħed mill-ġenerali
motivazzjonijiet għall factoring barra CSS tagħna

88
00:04:02,920 --> 00:04:04,057
l-aktar?

89
00:04:04,057 --> 00:04:05,280
>> UDJENZA: Użu mill-ġdid.

90
00:04:05,280 --> 00:04:05,785
>> DAVID Malan: Użu mill-ġdid.

91
00:04:05,785 --> 00:04:06,150
Dritt?

92
00:04:06,150 --> 00:04:09,470
Inti tista raw fil-p-set seba diġà
li ħafna tal-paġni, il-

93
00:04:09,470 --> 00:04:12,260
jixtru paġna, il-paġna tal-bejgħ, il-
paġna portafoll, huma probabbilment

94
00:04:12,260 --> 00:04:13,550
strutturati kemmxejn simili.

95
00:04:13,550 --> 00:04:17,579
Hemm logo finanzi CS50 fil-quċċata
sakemm inti iddeċidejt li jibdlu.

96
00:04:17,579 --> 00:04:19,839
Hemm footer fil-
qiegħ tal-paġni.

97
00:04:19,839 --> 00:04:24,315
U CSS jippermettilek mbagħad għall-fattur out
hija fis fajl separat b'tali mod li jekk

98
00:04:24,315 --> 00:04:27,780
inti trid tibdel xi ħaġa globalment
madwar is-sit kollu tiegħek, inti tista 'verament

99
00:04:27,780 --> 00:04:29,390
biss bidla fil-post wieħed.

100
00:04:29,390 --> 00:04:32,750
>> Iżda hemm prezz li inti tħallas potenzjalment
billi fatturati l-

101
00:04:32,750 --> 00:04:38,380
CSS minn file HTML tiegħi ġo separata
fajl referenzar ma 'l-

102
00:04:38,380 --> 00:04:40,650
tag, li rajna nhar it-Tnejn.

103
00:04:40,650 --> 00:04:43,850
Liema jista 'l-tnaqqis ikun ta' dan?

104
00:04:43,850 --> 00:04:48,830
Ħsieb lura ġimgħa ilu li meta nkunu
jitkellem dwar HTTP u TCP / IP u kif

105
00:04:48,830 --> 00:04:52,070
l-internet xogħlijiet.

106
00:04:52,070 --> 00:04:53,530
Xi ħaġa fuq hawn?

107
00:04:53,530 --> 00:04:54,730
>> UDJENZA: Huwa jieħu aktar ħin.

108
00:04:54,730 --> 00:04:55,470
>> DAVID Malan: Huwa jieħu aktar ħin.

109
00:04:55,470 --> 00:04:56,750
Għaliex?

110
00:04:56,750 --> 00:04:59,450
>> UDJENZA: [inaudible].

111
00:04:59,450 --> 00:04:59,750
>> DAVID Malan: Yeah.

112
00:04:59,750 --> 00:05:01,240
Għalhekk forsi jieħu ftit aktar ħin.

113
00:05:01,240 --> 00:05:04,290
Għaliex wieħed, il-CSS huwa ovvjament
mhux fl-istess fajl.

114
00:05:04,290 --> 00:05:06,920
Allura issa inti għandek tagħmel ma
wieħed, iżda żewġ talbiet.

115
00:05:06,920 --> 00:05:11,230
U kull wieħed minn dawk it-talbiet kif rajna fil-
Chrome fl-hekk imsejħa Ispettur,

116
00:05:11,230 --> 00:05:15,740
u ħarisna lejn il-tab netwerk, kull
ta 'dawn il-fajls jeħtieġ HTTP wieħed

117
00:05:15,740 --> 00:05:18,360
talba, li rajna jieħu
xi ammont ta 'ħin.

118
00:05:18,360 --> 00:05:19,290
Issa, forsi mhuwiex ħafna.

119
00:05:19,290 --> 00:05:20,670
Forsi huwa biss 20 millisekondi.

120
00:05:20,670 --> 00:05:22,260
Forsi huwa 200 millisekondi.

121
00:05:22,260 --> 00:05:25,530
>> Imma naħseb dwar page bħal Facebook,
jew CNN, jew Google, li huma ħafna

122
00:05:25,530 --> 00:05:28,060
akbar mill-eżempji konna
ħares lejn s'issa.

123
00:05:28,060 --> 00:05:32,070
Dawk il-paġni jista 'jkollhom għexieren ta' fajls,
kull wieħed minnhom jistgħu jeħtieġu

124
00:05:32,070 --> 00:05:33,550
download ta 'fajl.

125
00:05:33,550 --> 00:05:35,800
Sabiex l-affarijiet jistgħu potenzjalment
tibda jmajna.

126
00:05:35,800 --> 00:05:39,280
>> U speċjalment f'dawn il-jiem meta aħna kollha
mowbajls fil-bwiet tagħna u

127
00:05:39,280 --> 00:05:43,010
konnessjonijiet internet bil-mod, li biex
stenna ftit millisekondi aktar, ftit

128
00:05:43,010 --> 00:05:46,110
aktar millisekondi għall addizzjonali
fajls jista 'attwalment jiġi bil-mod.

129
00:05:46,110 --> 00:05:50,430
Latency hija l-kelma li tiddeskrivi l-
tip ta 'stennija li inti għandek li inti

130
00:05:50,430 --> 00:05:53,110
esperjenza meta stennija għal
xi biċċa informazzjoni.

131
00:05:53,110 --> 00:05:54,430
>> Iżda hemm rasu.

132
00:05:54,430 --> 00:05:56,600
Għalhekk mhuwiex kull tip ta 'a -

133
00:05:56,600 --> 00:05:58,170
fatt huwa daqsxejn ta 'seesaw hawn.

134
00:05:58,170 --> 00:06:02,970
Negattivi issa, imma dak browsers tista 'tagħmel
jekk dawn qed intelliġenti sabiex jevitaw

135
00:06:02,970 --> 00:06:08,870
jkollhom bżonn jitolbuha-istess styles.css
fajl mill-ġdid jista 'jkun li jagħmel xiex?

136
00:06:08,870 --> 00:06:09,390
>> Cache dan.

137
00:06:09,390 --> 00:06:10,370
Allura caching -

138
00:06:10,370 --> 00:06:11,690
C-A-C-H-E -

139
00:06:11,690 --> 00:06:15,810
ġeneralment ifisser hawn biss biex isalva l-
fajl inti mitlub-ewwel darba, u

140
00:06:15,810 --> 00:06:17,440
mbagħad tiċċekkja cache tiegħek għaliha.

141
00:06:17,440 --> 00:06:20,400
Iċċekkja int tip ta 'kontenitur tal-ħażna,
u jekk diġà għandek

142
00:06:20,400 --> 00:06:24,520
kopja ta 'styles.css, anke jekk xi oħra
paġna fil-p-set, jew kwalunkwe websajt,

143
00:06:24,520 --> 00:06:28,560
jitlob mill-ġdid, biss biex jagħtu l-
utent li kopja istess Cached.

144
00:06:28,560 --> 00:06:30,140
Ma jolqot li jitolbuha.

145
00:06:30,140 --> 00:06:32,560
>> Negattivi hemmhekk, għalkemm, kif xi wħud minnkom
jkunu tripped fuq fil-p-set.

146
00:06:32,560 --> 00:06:35,870
Jekk inti tagħmel bidla fuq is-server u
tmur lura għall-browser u int

147
00:06:35,870 --> 00:06:39,250
rikarigu, xi kultant il-browser ma
inti a favor u ma jolqot

148
00:06:39,250 --> 00:06:43,660
mill-ġdid tniżżil fajl styles.css tiegħek
għaliex, jaqgħu fuq, liema huma l-odds

149
00:06:43,660 --> 00:06:47,620
li dawn l-istili li Facebook użi
huma se jibdlu siegħa sa siegħa jew

150
00:06:47,620 --> 00:06:48,140
jum għal jum?

151
00:06:48,140 --> 00:06:48,800
Huwa pjuttost baxx.

152
00:06:48,800 --> 00:06:52,260
Huma jistgħu jinbidlu maż-żmien, iżda mhux
mill-minuta jew mill-siegħa.

153
00:06:52,260 --> 00:06:55,810
>> Allura trick, biss FYI web meta tagħmel
iżvilupp, huwa spiss żomm il-

154
00:06:55,810 --> 00:06:59,500
bidla ewlenija għall-eżempju u mbagħad ikklikkja
rikarigu fil-browser tiegħek, u li se

155
00:06:59,500 --> 00:07:03,280
tipikament tgħid il-rikarigu browser
kollox, anki jekk diġà għandek

156
00:07:03,280 --> 00:07:04,180
fil-cache.

157
00:07:04,180 --> 00:07:06,630
Għalhekk għal darb'oħra, upsides u negattivi,
iżda kollha kemm huma

158
00:07:06,630 --> 00:07:08,260
finalment disinn deċiżjonijiet.

159
00:07:08,260 --> 00:07:11,520
>> Allura issa, aħna ma biss
tispiċċa l-istorja hawn.

160
00:07:11,520 --> 00:07:15,790
Jekk I issa jmorru lura u lura u lura u
lura, bdejna biex jintroduċu mhux biss

161
00:07:15,790 --> 00:07:18,060
HTML, imma PHP.

162
00:07:18,060 --> 00:07:20,786
Allura f'termini laymans, dak
ma PHP jgħidilna jagħmlu?

163
00:07:20,786 --> 00:07:22,770
>> UDJENZA: [inaudible].

164
00:07:22,770 --> 00:07:24,258
>> DAVID Malan: X'hemm li?

165
00:07:24,258 --> 00:07:25,250
>> UDJENZA: Introduċi loġika
fil-kodiċi.

166
00:07:25,250 --> 00:07:26,620
>> DAVID Malan: Yeah, jintroduċu
loġika fid-kodiċi tiegħek.

167
00:07:26,620 --> 00:07:29,570
Allura huwa lingwa ta 'programmar vera
ma loops, u varjabbli, u

168
00:07:29,570 --> 00:07:32,620
funzjonijiet, u kondizzjonijiet, u kollha ta '
l-affarijiet aħna kont qed tuża mod lura

169
00:07:32,620 --> 00:07:33,780
meta sa mill-bidu.

170
00:07:33,780 --> 00:07:36,780
U PHP, Rajna, jistgħu jintużaw
jew fil-linja tal-kmand - huwa

171
00:07:36,780 --> 00:07:39,190
ma għandhomx għalfejn ikollhom xejn x'jaqsmu ma
mal-web, anki jekk dan huwa

172
00:07:39,190 --> 00:07:43,150
verament oriġini tagħha u dak li hemm tendenza
tkun tajba fuq u li jwasslu għal -

173
00:07:43,150 --> 00:07:47,130
iżda tista 'tuża PHP sempliċement min-natura
tal-fatt li hija għandha print ()

174
00:07:47,130 --> 00:07:49,660
funzjoni, u printf () funzjoni,
jew eku () funzjoni.

175
00:07:49,660 --> 00:07:52,440
Hemm għenieqed ta 'modi kif inti
jistgħu jistampaw test ma PHP.

176
00:07:52,440 --> 00:07:56,540
>> Għalhekk, inti tista 'tuża din il-programmazzjoni
lingwa output eżattament

177
00:07:56,540 --> 00:07:58,460
dak li konna nitkellmu qabel.

178
00:07:58,460 --> 00:08:01,360
Tista dinamikament jiġġeneraw
HTML tiegħek.

179
00:08:01,360 --> 00:08:02,300
Forsi mhux kollha ta 'dan.

180
00:08:02,300 --> 00:08:06,460
Forsi inti affarijiet kodiċi iebes, bħall-
header, u l-footer, u l-logo,

181
00:08:06,460 --> 00:08:07,950
u folji stil tiegħek,
u kollha ta 'dak.

182
00:08:07,950 --> 00:08:11,190
Iżda għal xi ħaġa bħal-p stabbiliti sebgħa,
fejn int manipulazzjoni ħażniet u

183
00:08:11,190 --> 00:08:14,690
turi portafoll tal-utent, li huwa
se jibdlu dinamiku, inti tista '

184
00:08:14,690 --> 00:08:18,960
żgur jużaw PHP u l-loġika tagħti
inti bħala lingwa ta 'programmar li

185
00:08:18,960 --> 00:08:22,320
output dinamiku sottogruppi
tal-paġna.

186
00:08:22,320 --> 00:08:25,900
>> Allura meta tkellem dwar websajts dinamiku,
jew programmar web, li

187
00:08:25,900 --> 00:08:27,200
dak li int verament jitkellem dwar.

188
00:08:27,200 --> 00:08:31,450
Bl-użu ta 'lingwa bħal PHP, jew affarijiet
imsejħa Python, jew Ruby, jew Java, jew

189
00:08:31,450 --> 00:08:35,900
għadhom lingwi oħra, għall-mistoqsija database
spiss, jew server ieħor, u

190
00:08:35,900 --> 00:08:38,580
imbagħad dinamikament bżiq out HTML.

191
00:08:38,580 --> 00:08:42,470
>> Issa r-riżultat aħħari, bħala twarrib, huwa
li l-HTML tal-websites l-iktar,

192
00:08:42,470 --> 00:08:45,970
inkluż p sett seba tiegħek, huwa probabbilment
se jkun mess enormi jekk

193
00:08:45,970 --> 00:08:48,060
inti tħares lejn is-sors
kodiċi fil-browser.

194
00:08:48,060 --> 00:08:49,010
Li mhux big deal.

195
00:08:49,010 --> 00:08:51,550
F'dan il-punt, meta aħna kura dwar
stil, aħna kura dwar il-

196
00:08:51,550 --> 00:08:52,740
Jittieħed li tikteb.

197
00:08:52,740 --> 00:08:56,240
Aħna mhux se kura dwar l-għalf
li dak outputs kodiċi tiegħek.

198
00:08:56,240 --> 00:08:59,520
Allura ma joqogħdu jinkwetaw dwar indentazzjoni
hawn jekk huwa PHP li l-

199
00:08:59,520 --> 00:09:01,190
attwalment outputting Jittieħed.

200
00:09:01,190 --> 00:09:04,430
Wara kollox, il-browser mhux se kura,
u l-bniedem mhux se tkun qed tfittex

201
00:09:04,430 --> 00:09:05,400
fis-sors xorta waħda.

202
00:09:05,400 --> 00:09:09,000
Aħna l-istaff, per eżempju, kieku
tkun tħares lejn PHP tiegħek.

203
00:09:09,000 --> 00:09:13,440
>> So let me jagħtu eżempju ta 'malajr issa
ta 'għaliex inkella dan jista' jkun utli.

204
00:09:13,440 --> 00:09:18,620
So franchement, I ma tistax tiftakar l-aħħar
ħin I użati C biex isolvu problema fl

205
00:09:18,620 --> 00:09:19,620
-dinja reali.

206
00:09:19,620 --> 00:09:22,330
Kien probabbilment fl-iskola graduate meta
I meħtieġa biex jużaw lingwa li

207
00:09:22,330 --> 00:09:26,710
kien livell pjuttost baxx u tatni l-
opportunità li jagħmel xi ħaġa għolja ħafna

208
00:09:26,710 --> 00:09:30,720
jwettqu biex verament isalva CPU kemm
ċikli I kif jista ', fil-parti kbira

209
00:09:30,720 --> 00:09:33,990
minħabba I kienet qed tuża settijiet ta 'data kbar,
u kull ċiklu CPU magħduda.

210
00:09:33,990 --> 00:09:37,750
U franchement, anke fl-affarijiet bħal telefowns
dawn il-jiem u tagħmir ieħor

211
00:09:37,750 --> 00:09:39,910
fejn inti ma pjuttost jkollhom kemm
memorja u inti ma pjuttost jkollhom bħala

212
00:09:39,910 --> 00:09:44,160
CPU ħafna, jużaw lingwi aktar mgħaġġel
għadu attraenti.

213
00:09:44,160 --> 00:09:47,290
>> Imma fid-dinja reali, meta inti biss
tixtieq li tarmi xi programm flimkien biex

214
00:09:47,290 --> 00:09:50,340
janalizzaw xi data, jew inti ħadthom miġbura
mazz sħiħ ta 'reġistrazzjonijiet għall-

215
00:09:50,340 --> 00:09:53,330
xi grupp student u inti tixtieq li ħafna
malajr awtomat jibgħat emails

216
00:09:53,330 --> 00:09:56,240
wieħed wieħed għal kull wieħed minn dawk
reġistranti, int ser jilħqu għall-

217
00:09:56,240 --> 00:09:59,240
lingwa f'livell ogħla
minn C biex ngħidu hekk.

218
00:09:59,240 --> 00:10:04,060
Xi ħaġa bħal PHP jew Python, jew Ruby,
jew xi oħrajn nofs tuzzana li jeżistu

219
00:10:04,060 --> 00:10:04,550
dawn il-jiem.

220
00:10:04,550 --> 00:10:07,200
Iżda dawk tlieta huma probabbilment
l-aktar trendy dritt issa.

221
00:10:07,200 --> 00:10:10,840
>> U dak li dan ifisser huwa li inti tista 'tiftaħ
up editur test bħal gedit jew

222
00:10:10,840 --> 00:10:14,030
xejn aktar ieħor u mbagħad biss tibda
miktub kodiċi mingħajr ma joqogħdu jinkwetaw

223
00:10:14,030 --> 00:10:17,800
dwar kompilazzjoni, mingħajr ma jkollhom
verament tinkwieta dwar ġestjoni tal-memorja,

224
00:10:17,800 --> 00:10:20,820
jżomm f'moħħu li għalkemm ftit
sloppiness eventwalment se terga 'lura

225
00:10:20,820 --> 00:10:24,790
li gidma inti jekk is-sett tad-dejta gets
akbar jew l-problema gets big.

226
00:10:24,790 --> 00:10:27,230
Imma din xi tfisser għan
us hija s-segwenti.

227
00:10:27,230 --> 00:10:29,860
>> Let me imorru quddiem u run speller
minn problema stabbiliti sitt.

228
00:10:29,860 --> 00:10:33,480
Allura dan huwa l-implimentazzjoni bbażata fuq trie tiegħi
I li jintużaw fuq il-big

229
00:10:33,480 --> 00:10:35,500
board fejn I titwettaq mhux hekk ukoll.

230
00:10:35,500 --> 00:10:38,720
Aħna ser terga 'lura fi żmien ġimgħa u
tirrevedi dawk li ma jispiċċaw atop-

231
00:10:38,720 --> 00:10:40,430
board big fl-aħħar lecture tagħna.

232
00:10:40,430 --> 00:10:44,520
Iżda għal issa, let me imorru quddiem u biss
run tiegħi soluzzjoni fit-test, u aħna ser nagħmlu

233
00:10:44,520 --> 00:10:48,460
il-Bibbja James King, u here we go.

234
00:10:48,460 --> 00:10:51,080
>> Għalhekk dawn huma kollha ta 'l-allegatament
kliem misspelled minn

235
00:10:51,080 --> 00:10:52,240
il-Bibbja James King.

236
00:10:52,240 --> 00:10:55,560
U l-implimentazzjoni tiegħi ħa
nofs sekonda b'kollox.

237
00:10:55,560 --> 00:10:58,270
Allura mhux wisq ħżiena fuq dan
partikolari kompjuter.

238
00:10:58,270 --> 00:11:01,540
Imma naħseb ta 'kemm
kodiċi I kellu jikteb.

239
00:11:01,540 --> 00:11:02,880
Aħseb kemm kodiċi kellek jiktbu.

240
00:11:02,880 --> 00:11:06,170
Aħseb kemm sigħat inti jintefqu fil-
D-sala jew dorm tiegħek jew fejn

241
00:11:06,170 --> 00:11:07,890
attwalment kodifikazzjoni up din is-soluzzjoni.

242
00:11:07,890 --> 00:11:11,850
>> Ukoll, jekk I attwalment ikollhom livell ogħla
lingwa bħal PHP, jieħdu nota ta '

243
00:11:11,850 --> 00:11:13,350
dak I tista 'tagħmel hawn.

244
00:11:13,350 --> 00:11:16,410
L-ewwel, ejja ngħidu li dan huwa minflok
kodiċi ta 'distribuzzjoni tiegħek.

245
00:11:16,410 --> 00:11:17,790
Dan huwa fajl imsejjaħ speller.

246
00:11:17,790 --> 00:11:20,220
Huwa disponibbli bħala parti mill-lum
kodiċi ta 'distribuzzjoni.

247
00:11:20,220 --> 00:11:22,670
U jien ser mewġa naħa tiegħi l-aktar
tad-dettalji, iżda dan huwa attwalment

248
00:11:22,670 --> 00:11:25,500
eżempju interessanti ta 'kif
inti tista port lingwa

249
00:11:25,500 --> 00:11:28,870
bħal C quddiem għall PHP.

250
00:11:28,870 --> 00:11:33,420
I litteralment fetħet żewġ twieqi test,
waħda mal-verżjoni C tiegħi ta 'speller.c,

251
00:11:33,420 --> 00:11:36,960
u I biss beda jagħmel traduzzjoni tagħha fil tiegħi
ras għal PHP u tajping bl-użu

252
00:11:36,960 --> 00:11:38,840
-funzjonijiet ekwivalenti eqreb.

253
00:11:38,840 --> 00:11:40,100
>> Allura xi wħud minn dawn l-affarijiet huma differenti.

254
00:11:40,100 --> 00:11:43,730
Rajna aħħar darba li PHP ma jużax
jinkludu fil pjuttost l-istess mod.

255
00:11:43,730 --> 00:11:47,050
Hija tuża jeħtieġu tipikament, għalkemm
jinkludu ma jeżistu.

256
00:11:47,050 --> 00:11:50,330
Iddefinixxi hija ftit differenti minn
# Jiddefinixxu C, iżda li

257
00:11:50,330 --> 00:11:51,890
kif nagħmlu kostanti.

258
00:11:51,890 --> 00:11:55,860
$ Argc jirriżulta teżisti fil-PHP,
hekk aħna stajt tidher li qabel.

259
00:11:55,860 --> 00:11:58,650
Dawn huma biss varjabbli, kollha ta '
li tibda bil sinjali dollaru.

260
00:11:58,650 --> 00:12:00,590
Recall dawn huma biss mazz
tal-punti varjabbli.

261
00:12:00,590 --> 00:12:03,970
>> Allura storja twila fil-qosor, inti qed jilqgħu biex
flip permezz ta 'dan jekk kurjuż, dan huwa

262
00:12:03,970 --> 00:12:10,010
kważi konverżjoni linja-għal-linja tal-
Verżjoni C tal speller.c fis PHP.

263
00:12:10,010 --> 00:12:12,630
U inti tista 'tagħmel dan mill-ġdid għal
nofs tużżana lingwi oħra.

264
00:12:12,630 --> 00:12:14,910
>> Imma x'hemm interessanti hija din.

265
00:12:14,910 --> 00:12:16,910
Jew x'hemm franchement diżappuntanti
hija din.

266
00:12:16,910 --> 00:12:20,790
Let me imorru quddiem u tip dwar
dictionary.php, u t-talba li jien

267
00:12:20,790 --> 00:12:23,670
se jmorru 'l quddiem u jimplimenta mill-ġdid
problema stabbiliti sitt hawn.

268
00:12:23,670 --> 00:12:27,530
>> Mela ejja tipproponi ewwel li f'dan il-
fajl, li ser jiġi implimentat

269
00:12:27,530 --> 00:12:30,550
PHP, so let me tiftaħ tags tiegħi bħal dik.

270
00:12:30,550 --> 00:12:34,780
Ħalli nagħtikom myself globali
varjabbli, $ daqs gets żero.

271
00:12:34,780 --> 00:12:36,710
U jien ser jagħti
myself tabella hash.

272
00:12:36,710 --> 00:12:38,110
I ser tuża tabella hash għal dan il-ħaġa.

273
00:12:38,110 --> 00:12:42,070
Kif nista 'niddikjara tabella hash fil-PHP?

274
00:12:42,070 --> 00:12:42,990
Magħmul.

275
00:12:42,990 --> 00:12:43,980
OK.

276
00:12:43,980 --> 00:12:48,870
>> Bracket hekk miftuħa parentesi magħluqa jirrappreżenta
dak fil-PHP, kif aħna stajt tidher?

277
00:12:48,870 --> 00:12:51,850
Firxa, iżda firxa li jistgħu
jkun firxa assoċjattiva.

278
00:12:51,850 --> 00:12:54,320
Firxa assoċjattiva hija
struttura data li

279
00:12:54,320 --> 00:12:55,860
jassoċja keys b'valuri.

280
00:12:55,860 --> 00:12:59,430
>> Issa fl-aktar sempliċi numerikament indiċjati
array, dawk ċwievet huma dak?

281
00:12:59,430 --> 00:13:02,250

282
00:13:02,250 --> 00:13:03,960
Żero, wieħed, tnejn, tlieta, id-dritt?

283
00:13:03,960 --> 00:13:08,780
Iskola antika Jittieħed lura minn C. Iżda tista '
wkoll tkun kordi bħal foo, u bar,

284
00:13:08,780 --> 00:13:12,210
jew Maxwell, jew kwalunkwe string tali.

285
00:13:12,210 --> 00:13:14,240
So I tista 'lieva li
fi ftit mument.

286
00:13:14,240 --> 00:13:17,550
>> Let me imorru quddiem u jiddikjaraw
funzjoni simili -

287
00:13:17,550 --> 00:13:19,020
ejja do tagħbija () l-ewwel.

288
00:13:19,020 --> 00:13:20,690
Allura tagħbija funzjoni ().

289
00:13:20,690 --> 00:13:23,440
U PHP huwa xi ftit differenti f'dik
inti litteralment tip funzjoni, imma int

290
00:13:23,440 --> 00:13:24,930
ma tip għal tip ta 'ritorn.

291
00:13:24,930 --> 00:13:28,760
Jien ser imorru quddiem u jgħidu li l-
tagħbija () funzjoni għandha tieħu fil

292
00:13:28,760 --> 00:13:31,000
argument dizzjunarju $, just
bħal verżjoni C għamlet.

293
00:13:31,000 --> 00:13:32,510
Jien tagħmel dan mill-memorja.

294
00:13:32,510 --> 00:13:34,910
>> U nipproponi li jien
se tagħmel dan.

295
00:13:34,910 --> 00:13:37,080
Jien sempliċiment se jagħmlu foreach.

296
00:13:37,080 --> 00:13:40,710
Jien ser sejħa funzjoni msejħa
fajl (), li jgħaddi fl-isem ta 'dik

297
00:13:40,710 --> 00:13:44,990
fajl, li hija l-varjabbli
$ Dizzjunarju bħala $ kelma.

298
00:13:44,990 --> 00:13:49,410
U mbagħad ġewwa ta 'tiegħi għal loop hawn, jien
se jmorru quddiem u jaħżen fil tiegħi

299
00:13:49,410 --> 00:13:57,440
$ Tabella li $ kelma gets veru.

300
00:13:57,440 --> 00:13:57,918
Magħmul.

301
00:13:57,918 --> 00:14:01,264
Oh, stenna.

302
00:14:01,264 --> 00:14:02,422
Magħmul.

303
00:14:02,422 --> 00:14:02,760
OK.

304
00:14:02,760 --> 00:14:04,970
>> Li hija t-tagħbija () funzjoni
jiġifieri fil PHP.

305
00:14:04,970 --> 00:14:05,865
Issa, għaliex ma li jaħdmu?

306
00:14:05,865 --> 00:14:07,010
U jien tip ta 'qerq hawn.

307
00:14:07,010 --> 00:14:09,980
>> Għalhekk, wieħed, foreach rajna
qosor aħħar darba.

308
00:14:09,980 --> 00:14:13,680
Dan ifisser biss li inti tista 'jtenni fuq
firxa mingħajr bothering ma 'i

309
00:14:13,680 --> 00:14:16,150
u n u plus plus, u kollha ta 'dak.

310
00:14:16,150 --> 00:14:21,350
Dizzjunarju huwa naturalment l-isem fajl,
xi ħaġa simili kbar jew żgħar, it-tnejn

311
00:14:21,350 --> 00:14:22,830
dizzjunarji aħna użati aħħar darba.

312
00:14:22,830 --> 00:14:26,715
File hija funzjoni li jiftaħ test
file, jaqraha fid linja b'linja, u

313
00:14:26,715 --> 00:14:29,840
idejn inti back firxa enormi,
kull wieħed mill-elementi li hija

314
00:14:29,840 --> 00:14:31,340
linja minn dan il-fajl.

315
00:14:31,340 --> 00:14:36,040
Allura dak hu l-kombinazzjoni ta 'fopen, u
fread, u filwaqt li loop, u fclose,

316
00:14:36,040 --> 00:14:37,080
u kollha ta 'dak.

317
00:14:37,080 --> 00:14:40,150
Finalment, kif kelma ifisser biss dak l-
varjabbli jien ser ikollhom aċċess għal

318
00:14:40,150 --> 00:14:41,890
fuq kull iterazzjoni f'dan loop.

319
00:14:41,890 --> 00:14:46,910
>> Għalhekk fil-qosor, dan liner waħda hawnhekk tfisser
tiftaħ il-fajl li ismu huwa

320
00:14:46,910 --> 00:14:50,750
dizzjunarju, il-varjabbli, iterazzjoni fuq
huwa linja b'linja, u kull darba ikollok

321
00:14:50,750 --> 00:14:54,290
linja, aħżen fi varjabbli imsejjaħ kelma,
u mbagħad tagħmel xi ħaġa ma kelma.

322
00:14:54,290 --> 00:14:55,280
What do I trid tagħmel?

323
00:14:55,280 --> 00:14:58,110
I tixtieq li tqiegħed kelma fis tabella hash tiegħi.

324
00:14:58,110 --> 00:15:00,860
>> Well, I tista 'tpoġġi xi ħaġa fil tiegħi
hash tabella bħal fil C

325
00:15:00,860 --> 00:15:02,140
jużaw parentesi kwadri.

326
00:15:02,140 --> 00:15:03,660
Dan huwa l-isem għall-mejda hash tiegħi.

327
00:15:03,660 --> 00:15:07,180
Jien ser indiċi f'dak hash
tabella li tinsab fil dan il-post.

328
00:15:07,180 --> 00:15:08,920
Allura mhux parentesi żero, ma parentesi wieħed.

329
00:15:08,920 --> 00:15:11,990
Quote Bracket xi ħaġa unquote,
tkun xi tkun din il-kelma hija.

330
00:15:11,990 --> 00:15:15,200
U bħad jista 'jkollok tiegħek
trie xogħol tabella hash, inti biss taħżen

331
00:15:15,200 --> 00:15:17,650
effettivament Boolean, impliċitament
jew espliċitament.

332
00:15:17,650 --> 00:15:18,260
Magħmul.

333
00:15:18,260 --> 00:15:20,000
Jien ħażna tal-valur veru.

334
00:15:20,000 --> 00:15:23,150
>> Issa hemm koppja ta 'affarijiet
Jien qtugħ kantunieri hawn fuq.

335
00:15:23,150 --> 00:15:27,720
Teknikament, hemm għaddej li jkun
linja l-ġdida annoying, / n, fl-aħħar ta '

336
00:15:27,720 --> 00:15:28,820
kull wieħed minn dawn il-kliem.

337
00:15:28,820 --> 00:15:31,770
So I għandhom probabbilment sejħa funzjoni PHP
imsejħa CHOP (), li se

338
00:15:31,770 --> 00:15:33,460
pjuttost litteralment CHOP li off.

339
00:15:33,460 --> 00:15:35,020
And I attwalment ħtieġa li
jagħmlu ħaġa waħda oħra.

340
00:15:35,020 --> 00:15:38,380
I għandhom probabbilment inkrement daqs fuq kull
iterazzjoni, hekk jien iżżomm rekord

341
00:15:38,380 --> 00:15:39,560
globalment ta 'dak li hu.

342
00:15:39,560 --> 00:15:43,180
U franchement, u dan huwa wieħed mill-
aspetti stupider ta 'PHP, jekk int

343
00:15:43,180 --> 00:15:46,950
użu ta 'varjabbli globali, għandek bżonn
jiġifieri b'mod espliċitu li int.

344
00:15:46,950 --> 00:15:51,670
Hekk jien ser fil-fatt it-tip fil globali
$ Daqs, $ tabella globali, u issa

345
00:15:51,670 --> 00:15:52,690
funzjoni tiegħi hija kompluta.

346
00:15:52,690 --> 00:15:57,475
>> Allura mhux daqshekk sempliċi bħal qabel, iżda
probabbilment ħa inqas ħin mill-C

347
00:15:57,475 --> 00:15:58,220
verżjoni, forsi?

348
00:15:58,220 --> 00:15:58,730
OK.

349
00:15:58,730 --> 00:16:00,390
>> Allura issa ejja tagħmel il-verifika () funzjoni.

350
00:16:00,390 --> 00:16:04,300
Ejja naraw jekk dan l-inqas ħa l-
siegħa fuq il-għan li hija ħadet us C. So

351
00:16:04,300 --> 00:16:06,500
let me imorru quddiem u jiddikjaraw
check bħala funzjoni.

352
00:16:06,500 --> 00:16:09,070
Jieħu fil argument kelma, li hija
ser jiġu minn speller.

353
00:16:09,070 --> 00:16:13,410
U jien biss se tivverifika jekk il-
isset varjabbli li ġej, tabella

354
00:16:13,410 --> 00:16:18,400
strtolower bracket tal-kelma -

355
00:16:18,400 --> 00:16:20,590
ejja bilanċ kollha ta 'parentesi tiegħi -

356
00:16:20,590 --> 00:16:24,275
mbagħad jirritornaw veru.

357
00:16:24,275 --> 00:16:27,020

358
00:16:27,020 --> 00:16:28,460
Else -

359
00:16:28,460 --> 00:16:30,330
li kien verament l-hard
parti ta 'dan il-programm.

360
00:16:30,330 --> 00:16:31,940
Else, ritorn foloz.

361
00:16:31,940 --> 00:16:32,630
Magħmul.

362
00:16:32,630 --> 00:16:33,460
C'est verifika ().

363
00:16:33,460 --> 00:16:34,520
>> Issa, għaliex ma dan ix-xogħol?

364
00:16:34,520 --> 00:16:37,040
Well, waħda I għadda fil-kelma,
li hija sekwenza.

365
00:16:37,040 --> 00:16:41,400
Tnejn, jien iċċekkjar ġewwa tal-hash
tabella, li sejjaħ $ tabella.

366
00:16:41,400 --> 00:16:45,470
Jien tisfurzah biex zghar billi ċċempel
funzjoni pjuttost simili tolower () fil-

367
00:16:45,470 --> 00:16:48,580
C, iżda din ma l-kelma sħiħa,
mhux karattru wieħed.

368
00:16:48,580 --> 00:16:52,680
U jekk dan huwa stabbilit, fi kliem ieħor hemm
hija valur stabbilit, fi kliem ieħor,

369
00:16:52,680 --> 00:16:54,880
jekk huwa minnu, allura iva,
din hija kelma.

370
00:16:54,880 --> 00:16:56,530
Minħabba I poġġih hemmhekk b'tagħbija ().

371
00:16:56,530 --> 00:16:59,100
U jekk le, jien ser jirritorna falza.

372
00:16:59,100 --> 00:17:00,090
>> Issa l-oħrajn huma faċli.

373
00:17:00,090 --> 00:17:03,570
Daqs funzjoni (), kif nista 'nagħmlu dan?

374
00:17:03,570 --> 00:17:05,230
I essenzjalment tagħmel ritorn $ daqs.

375
00:17:05,230 --> 00:17:07,770
Imma I teknikament bżonn
tagħmel dan ħaġa annoying.

376
00:17:07,770 --> 00:17:10,640
U fil-fatt up tisma, I kien qtugħ
kantuniera wieħed wisq.

377
00:17:10,640 --> 00:17:12,920
I really bżonn tagħmel $ tabella globali.

378
00:17:12,920 --> 00:17:16,260
>> Imma dak li qal, jħottu).

379
00:17:16,260 --> 00:17:17,380
Jħottu () hija aqwa.

380
00:17:17,380 --> 00:17:20,500
Jħottu funzjoni ().

381
00:17:20,500 --> 00:17:23,990
Kif nista jridu jimplimentaw jħottu ()?

382
00:17:23,990 --> 00:17:25,079
Magħmul.

383
00:17:25,079 --> 00:17:25,450
OK.

384
00:17:25,450 --> 00:17:28,900
>> Allura jħottu (), il-ġestjoni tal-memorja huwa
kompletament tittieħed kura ta 'għalik fil-

385
00:17:28,900 --> 00:17:31,800
xi ħaġa bħal PHP u ħafna
ta 'lingwi ta' livell ogħla.

386
00:17:31,800 --> 00:17:32,600
Allura dan huwa aqwa.

387
00:17:32,600 --> 00:17:36,080
Bħall għaliex l-infern ma moħli-passat
tmien ġimgħat flimkien dwar il-kitba C

388
00:17:36,080 --> 00:17:41,030
apparentement verament bil-mod, tassew ħin
problemi jikkunsmaw bil għexieren ta 'sigħat

389
00:17:41,030 --> 00:17:42,530
xogħol taħt ċinturini tagħna?

390
00:17:42,530 --> 00:17:46,110
>> Ukoll, għal ħaġa waħda, dan jista 'xogħol
multa għall-programmi żgħar.

391
00:17:46,110 --> 00:17:47,840
Huwa ċertament titħaffef tiegħi
iżvilupp ta 'żmien.

392
00:17:47,840 --> 00:17:49,790
Imma ejja naraw x'jiġri
fid-dinja reali.

393
00:17:49,790 --> 00:17:52,370
>> Let me jmorru fis dan id-direttorju
fil-tieqa terminal.

394
00:17:52,370 --> 00:17:53,370
Hemm speller.

395
00:17:53,370 --> 00:17:56,570
U tinnota bħala twarrib, u inti tista '
ltaqgħu ma 'dan il-problema stabbiliti

396
00:17:56,570 --> 00:17:58,190
sitta jew problema stabbiliti seba.

397
00:17:58,190 --> 00:18:01,610
Inti ma jkunux strettament għandekx
jispiċċaw fajls PHP ma. PHP.

398
00:18:01,610 --> 00:18:05,250
Jekk inti tpoġġi linja bħal dik l-ewwel wieħed fuq
nett, li l-linja speċjali

399
00:18:05,250 --> 00:18:10,980
ta 'sintassi li essenzjalment ifisser jsibu
il-programm imsejjaħ PHP u jużaha biex

400
00:18:10,980 --> 00:18:12,270
jinterpretaw dan il-fajl.

401
00:18:12,270 --> 00:18:15,410
Allura issa l-ebda waħda verament jaf li
Niġri programm PHP.

402
00:18:15,410 --> 00:18:19,860
I tista 'taħdem biss daqslikieku
kienu xi ħaġa kkumpilati C.

403
00:18:19,860 --> 00:18:20,650
>> Iżda hawn l-ħaġa.

404
00:18:20,650 --> 00:18:21,600
Attwalment, ejja tagħmel dan mill-ġdid.

405
00:18:21,600 --> 00:18:23,530
Dropbox/pset6 /.

406
00:18:23,530 --> 00:18:25,390
Hemm speller.

407
00:18:25,390 --> 00:18:26,720
OK, 0.44 sekondi.

408
00:18:26,720 --> 00:18:28,080
Hija marret aktar mgħaġġla f'dan il-ħin.

409
00:18:28,080 --> 00:18:29,745
>> Issa ejja jmorru fil-verżjoni PHP.

410
00:18:29,745 --> 00:18:43,070

411
00:18:43,070 --> 00:18:44,320
Touch sbieħ.

412
00:18:44,320 --> 00:18:50,830

413
00:18:50,830 --> 00:18:53,285
Iżda biss jaħsbu kif ħafna ħin
I ffrankati fuq ħinijiet tal-uffiċċju.

414
00:18:53,285 --> 00:18:56,990

415
00:18:56,990 --> 00:18:57,790
OK.

416
00:18:57,790 --> 00:19:01,020
>> Allura 3.59 sekondi, li attwalment
ma ħoss preċiża jew.

417
00:19:01,020 --> 00:19:03,710
Iżda dan għaliex storja twila fil-qosor,
meta int stampar ammont kbir

418
00:19:03,710 --> 00:19:06,840
ta 'għalf għall-iskrin, li
innifsu inaqqas affarijiet isfel.

419
00:19:06,840 --> 00:19:11,260
Dak li verament ħa l-CPU fil-
appliance kien 3.59 sekondi, b'mod

420
00:19:11,260 --> 00:19:15,260
B'kuntrast ma 'C, li ħa 0.44
sekondi aktar reċentement.

421
00:19:15,260 --> 00:19:17,620
Li verament ordni ta '
kobor differenti.

422
00:19:17,620 --> 00:19:20,280
>> Għalhekk, fejn huwa dak il-prezz li ġejjin minn?

423
00:19:20,280 --> 00:19:21,790
Għaliex huwa tant kajman?

424
00:19:21,790 --> 00:19:24,220
Għaliex ma PHP twettaq tant fqir?

425
00:19:24,220 --> 00:19:25,242
Danielle?

426
00:19:25,242 --> 00:19:26,550
>> UDJENZA: Inti ma verament
jużaw tabella hash.

427
00:19:26,550 --> 00:19:27,710
>> DAVID Malan: I ma verament
jużaw tabella hash.

428
00:19:27,710 --> 00:19:28,760
So I tip ta 'ma.

429
00:19:28,760 --> 00:19:29,870
Allura huwa firxa assoċjattiva.

430
00:19:29,870 --> 00:19:33,650
Ħafna probabbli jekk il-poplu fil PHP huma
verament smart, huma użati minn taħt il-

431
00:19:33,650 --> 00:19:39,520
hood tabella hash attwali implimentata
fil xi ħaġa bħal C jew C + +.

432
00:19:39,520 --> 00:19:41,290
Imma.

433
00:19:41,290 --> 00:19:42,760
Yeah.

434
00:19:42,760 --> 00:19:44,010
>> UDJENZA: [inaudible].

435
00:19:44,010 --> 00:19:46,690

436
00:19:46,690 --> 00:19:47,080
>> DAVID Malan: Yeah.

437
00:19:47,080 --> 00:19:50,780
Allura kull wieħed mill-funzjonijiet I kiteb issa -
attwalment, tista 'tgħid li għal darba oħra

438
00:19:50,780 --> 00:19:51,480
ftit louder?

439
00:19:51,480 --> 00:19:54,509
>> UDJENZA: Kull wieħed mill-funzjonijiet li
Inkludejt għandha ħafna aktar sħiħa

440
00:19:54,509 --> 00:19:56,610
kapaċità minn -

441
00:19:56,610 --> 00:19:57,550
>> DAVID Malan: Allura li ħafna minnu.

442
00:19:57,550 --> 00:20:01,490
Hemm ħafna aktar overhead li aħna qed
mhux verament jaraw billi tiffoka biss fuq

443
00:20:01,490 --> 00:20:03,730
dictionary.php, li I biss kiteb.

444
00:20:03,730 --> 00:20:08,020
B'kuntrast, hemm interpretu kollu
għaddejjin fl-isfond.

445
00:20:08,020 --> 00:20:12,040
Tabilħaqq, meta I dam dan il-programm, huwa
ma kien għaddej żerijiet kkumpilata u dawk

446
00:20:12,040 --> 00:20:14,290
maħsuba għall-CPU Intel tiegħi.

447
00:20:14,290 --> 00:20:19,270
Pjuttost, huwa kien għaddej linja b'linja
Kodiċi PHP li jistenna eżattament

448
00:20:19,270 --> 00:20:20,350
simili aħna ittajpjat.

449
00:20:20,350 --> 00:20:22,475
U hekk meta tuża
lingwa interpretat, inti

450
00:20:22,475 --> 00:20:23,850
fatt iħallsu dan il-prezz.

451
00:20:23,850 --> 00:20:27,010
Huwa ser tieħu ftit ħin biex taqra
fajl tiegħek top għal isfel, xellug għal

452
00:20:27,010 --> 00:20:30,740
dritt, u mbagħad tesegwixxi kull
line u għal darb'oħra.

453
00:20:30,740 --> 00:20:34,250
>> Issa fir-realtà, speċjalment fuq il-web,
inti tista 'attwalment iħaffu dan il-proċess

454
00:20:34,250 --> 00:20:38,660
billi caching-riżultati tal-
Kodiċi PHP tkun interpretata.

455
00:20:38,660 --> 00:20:41,640
U li jagħmel sens fuq il-web, għaliex
jekk inti ma jkunux utent wieħed bħal

456
00:20:41,640 --> 00:20:46,300
me hawn, iżda 1,000 jew 10,000 utenti, allura
forsi l-ewwel darba li l-fajl huwa

457
00:20:46,300 --> 00:20:49,050
aċċessata huwa bil-mod, iżda wara
huwa ħafna aktar mgħaġġla.

458
00:20:49,050 --> 00:20:51,000
>> Iżda dan ukoll, għal darb'oħra, huwa off kummerċ.

459
00:20:51,000 --> 00:20:53,870
U għal xi ħaġa bħal dejta tar-riċerka
stabbiliti, jew saħansitra xi ħaġa kbira bħal

460
00:20:53,870 --> 00:20:58,330
dan, l-utenti tiegħek eventwalment se
tibda tħossok li tnaqqis.

461
00:20:58,330 --> 00:21:02,670
>> Għalhekk fil-qosor, interpretat il-lingwi huma
ħafna fil Vogue, popolari ħafna, u

462
00:21:02,670 --> 00:21:06,710
franchement huma probabbilment l-lingwi li
għandhom jilħqu għal meta jissolvew problemi

463
00:21:06,710 --> 00:21:08,200
sussegwenti CS50.

464
00:21:08,200 --> 00:21:12,720
Imma tirrealizza kemm int verament
tieħu għall mogħtija taħt il-barnuża

465
00:21:12,720 --> 00:21:15,910
verament dawk li għaddew diversi ġimgħat hash
imwejjed, u siġar, u tentattivi,

466
00:21:15,910 --> 00:21:20,770
li jintużaw finalment li attwalment
jimplimentaw affarijiet simili parentesi miftuħa,

467
00:21:20,770 --> 00:21:24,200
parentesi kwadri, li nistgħu issa
gratefully jieħdu għal mogħtija.

468
00:21:24,200 --> 00:21:26,360
>> Mela ejja tagħti ħarsa issa
f'dan il-kuntest web.

469
00:21:26,360 --> 00:21:29,890
U semmejt aħħar darba li hemm
mazz ta 'superglobals fil-PHP li

470
00:21:29,890 --> 00:21:32,490
ma humiex verament rilevanti
fil-linja tal-kmand.

471
00:21:32,490 --> 00:21:36,210
Huma qed aktar rilevanti fil-kuntest
ta 'użu PHP f'kuntest web.

472
00:21:36,210 --> 00:21:41,220
Allura running PHP fuq server web sabiex
biex jiġġeneraw għalf bħal HTML.

473
00:21:41,220 --> 00:21:44,540
>> U aħna glanced fil $ _GET u $ _POST, u
li fejn awtomatikament utenti "

474
00:21:44,540 --> 00:21:49,100
input jispiċċa sempliċiment jekk inti tissottometti
jiffurmaw għal fajl li jispiċċa fil. PHP fuq web

475
00:21:49,100 --> 00:21:50,460
server bħall-appliance.

476
00:21:50,460 --> 00:21:53,310
Imma ejja nħarsu ftit lejn
$ _COOKIE U $ _SESSION.

477
00:21:53,310 --> 00:21:56,670
>> F'termini layman, dak li huwa cookie bħala
inti tifhem li fil-kuntest ta '

478
00:21:56,670 --> 00:21:58,220
jużaw il-web?

479
00:21:58,220 --> 00:21:59,450
>> UDJENZA: File fuq il-kompjuter.

480
00:21:59,450 --> 00:21:59,920
>> DAVID Malan: Yeah.

481
00:21:59,920 --> 00:22:03,500
Huwa fajl fuq il-kompjuter l-utent
mħawla bi kwalunkwe website

482
00:22:03,500 --> 00:22:04,410
inti jiġri li jżuru.

483
00:22:04,410 --> 00:22:07,334
Allura meta inti tmur għall Facebook, meta tmur
li bankofamerica.com, meta tmur

484
00:22:07,334 --> 00:22:10,330
li google.com, meta inti tmur għal kważi kull
websajt fid-dinja f'dawn il-jiem,

485
00:22:10,330 --> 00:22:14,850
inkluż cs50.net, cookie hija mħawla
fuq il-kompjuter tiegħek, li huwa

486
00:22:14,850 --> 00:22:19,800
jew valur maħżuna fil RAM fil tiegħek
kompjuter fil-memorja tal-browser tiegħek, jew

487
00:22:19,800 --> 00:22:22,800
kultant tabilħaqq maħżuna fajl
fuq hard drive tiegħek.

488
00:22:22,800 --> 00:22:26,960
>> U x'hemm tipikament maħżuna f'dak il-fajl
mhuwiex isem l-utent tiegħek, mhux tiegħek

489
00:22:26,960 --> 00:22:31,060
password, tipikament mhux xi ħaġa
sensittivi ħlief jekk il-websajt ma tkunx hekk

490
00:22:31,060 --> 00:22:35,040
tajba mas-sigurtà tagħhom, iżda pjuttost
huwa identifikatur uniku big fost

491
00:22:35,040 --> 00:22:35,680
affarijiet oħra.

492
00:22:35,680 --> 00:22:38,920
Huwa numru bl-addoċċ big mħawla fuq tiegħek
kompjuter iżda inti tista 'taħseb kif

493
00:22:38,920 --> 00:22:42,740
tip ta 'timbru virtwali idejn simili minn
klabb jew xi park tad-divertiment li

494
00:22:42,740 --> 00:22:47,160
jippermetti l-persunal, is-sidien ta 'dak
servizz, li tiftakar min int.

495
00:22:47,160 --> 00:22:51,030
Allura jekk in-numru bl-addoċċ kbira hija simili
12345678, għalkemm dan huwa ovvjament

496
00:22:51,030 --> 00:22:54,180
mhux wisq każwali, think ta 'dak il-
timbru idejn li meta inti żżur

497
00:22:54,180 --> 00:22:57,930
facebook.com għall-ewwel darba, huma
timbru dak in-numru fuq naħa tiegħek.

498
00:22:57,930 --> 00:23:01,510
U allura għaliex inti titkellem HTTP, inti
tkun browser, u minħabba Facebook

499
00:23:01,510 --> 00:23:06,440
ovvjament jitkellem l-istess bħala web
server, il-protokoll HTTP jgħid li

500
00:23:06,440 --> 00:23:09,930
ghaċ sussegwentement żżur
facebook.com, kemm jekk huwa t-tieni

501
00:23:09,930 --> 00:23:13,560
aktar tard, siegħa wara, anke l-jum li jmiss,
sakemm int ma espliċitament

502
00:23:13,560 --> 00:23:17,050
logged out, li effettivament
huwa simili taħsel idejk.

503
00:23:17,050 --> 00:23:20,280
HTTP jgħid inti għandek tippreżenta tiegħek
timbru idejn kull darba li inti

504
00:23:20,280 --> 00:23:22,020
ritorn lejn dak website.

505
00:23:22,020 --> 00:23:24,390
>> What Facebook allura ma huma huma
tħares lejn dak timbru idejn u

506
00:23:24,390 --> 00:23:26,850
jgħidu, oh, 123456789.

507
00:23:26,850 --> 00:23:30,260
I do not know-ewwel daqqa t'għajn li dan
huwa David Malan fil Cambridge,

508
00:23:30,260 --> 00:23:34,690
Massachusetts, iżda huma jistgħu jikkontrollaw tagħhom
database u jgħidu, oh, il-persuna

509
00:23:34,690 --> 00:23:39,930
li fuq il-kompjuter aħna mħawla 123456789
huwa David Malan minn Cambridge,

510
00:23:39,930 --> 00:23:40,440
Massachusetts.

511
00:23:40,440 --> 00:23:46,000
Ejja juru li l-utent mbagħad profil tiegħu
paġna jew Feed News tiegħu.

512
00:23:46,000 --> 00:23:49,660
>> Imma hemm problema hawn jekk dan
hija kif il-web tabilħaqq xogħlijiet.

513
00:23:49,660 --> 00:23:51,390
Ejja tagħti ħarsa lejn eżempju malajr.

514
00:23:51,390 --> 00:23:55,190
Ejja fatt imorru jgħidu facebook.com.

515
00:23:55,190 --> 00:23:58,130
Iżda qabel ma nistgħu jmorru hemm, let
me imorru quddiem u tiftaħ Chrome

516
00:23:58,130 --> 00:23:59,790
Spettur stabbiliti hawn.

517
00:23:59,790 --> 00:24:01,140
Let me ħarsa lejn il-tab netwerk.

518
00:24:01,140 --> 00:24:06,020
U issa ejja imorru quddiem u tip
fil https://facebook.com.

519
00:24:06,020 --> 00:24:09,410
U jien tagħmel dan hekk li aħna ma tara
kollha ta 'dawk redirects u skart

520
00:24:09,410 --> 00:24:10,660
żmien tfittex permezz dawk.

521
00:24:10,660 --> 00:24:12,690
Let me hit jidħol.

522
00:24:12,690 --> 00:24:13,130
>> Kull dritt.

523
00:24:13,130 --> 00:24:14,580
Naraw mazz sħiħ ta 'talbiet.

524
00:24:14,580 --> 00:24:15,640
Hemm jaqa Facebook.

525
00:24:15,640 --> 00:24:16,930
Hemm mazz sħiħ ta 'fajls.

526
00:24:16,930 --> 00:24:19,290
U hawn, per aċċenn tiegħi ta '
aħħar darba latency, li

527
00:24:19,290 --> 00:24:21,240
ħafna ta 'talbiet HTTP.

528
00:24:21,240 --> 00:24:23,700
Iżda l-ewwel wieħed huwa probabbilment
l-aktar interessanti.

529
00:24:23,700 --> 00:24:26,420
>> Mela ejja iscroll down hawn, u
I ser zoom fit-tieni.

530
00:24:26,420 --> 00:24:29,090
Dan se jkun it-tip ta '
mess, imma ejja ara.

531
00:24:29,090 --> 00:24:31,660
Facebook huwa tibgħatilna
mazz sħiħ ta 'għalf.

532
00:24:31,660 --> 00:24:33,490
>> Iżda Whoa, interessanti.

533
00:24:33,490 --> 00:24:37,880
Huma qed tħawwil mhux wieħed, iżda erba '
timbri idejn għal fuq naħa tiegħi hawnhekk.

534
00:24:37,880 --> 00:24:40,400
Set-cookie, Set-cookie, set-cookie,
set cookie.

535
00:24:40,400 --> 00:24:44,030
U hemm ftit karatteristiċi hawn.

536
00:24:44,030 --> 00:24:46,170
Kollha kemm huma jsemmu xi
tip ta 'skadenza.

537
00:24:46,170 --> 00:24:50,090
U jidher qisu Facebook qed jittama
tiftakar lili sal-2015.

538
00:24:50,090 --> 00:24:53,670
Allura dak preżumibbilment sa meta
I trid login jew dawn ser biss

539
00:24:53,670 --> 00:24:55,710
awtomatikament jassumu jien
mhux ġejjin lura.

540
00:24:55,710 --> 00:24:57,840
Allura li attwalment deċenti
ammont ta 'ħin.

541
00:24:57,840 --> 00:24:59,170
>> U hemm xi oħra
affarijiet għaddejjin hawn.

542
00:24:59,170 --> 00:25:03,036
Dan cookie jidher li bil-forza
imħassra billi qal li skada fl-1970

543
00:25:03,036 --> 00:25:04,460
qabel kienu jeżistu cookies.

544
00:25:04,460 --> 00:25:06,510
Allura l-browser huwa biss se
li wieħed jassumi OK, dan huwa simili

545
00:25:06,510 --> 00:25:07,910
ħasil tal-idejn timbru.

546
00:25:07,910 --> 00:25:11,240
>> Imma issa meta browser tiegħi jagħmel
talba sussegwenti -

547
00:25:11,240 --> 00:25:14,340
let me imorru quddiem u tagħmel dan
ġdid u rikarigu.

548
00:25:14,340 --> 00:25:18,170
Issa let me iscroll lura lill-
talba fuq u jinżlu

549
00:25:18,170 --> 00:25:20,760
hawn, titlob headers.

550
00:25:20,760 --> 00:25:21,390
Avviż dan.

551
00:25:21,390 --> 00:25:25,280
Allura issa jien taħt mhux headers rispons,
iżda tinnota li jgħid talba headers.

552
00:25:25,280 --> 00:25:29,220
U tinnota li browser tiegħi bħala parti mill-
talba tagħha wara laqtu rikarigu għandha

553
00:25:29,220 --> 00:25:32,780
mibgħut mill-inqas dan li ġej
informazzjoni.

554
00:25:32,780 --> 00:25:34,670
Mhux stabbiliti-cookie, iżda cookie.

555
00:25:34,670 --> 00:25:38,750
Allura dan huwa l-linja, l-header HTTP hekk
biex jitkellmu, fejn browser tiegħi huwa tip

556
00:25:38,750 --> 00:25:43,340
mingħajr ma jkunu jafu tiegħi jippreżentaw
naħa tiegħi għall-ispezzjoni Facebook.

557
00:25:43,340 --> 00:25:46,020
>> Allura dawn il-cookies jistgħu jkunu
użata imbagħad għal liema?

558
00:25:46,020 --> 00:25:49,420
Li tiftakar min int, jew tiftakar kif
ħafna drabi inti ħadthom kien hemm, jew

559
00:25:49,420 --> 00:25:50,280
verament xejn.

560
00:25:50,280 --> 00:25:52,742
>> Allura hawnhekk huwa counter.php.

561
00:25:52,742 --> 00:25:53,780
U let me zoom fl fuq il-font.

562
00:25:53,780 --> 00:25:58,380
U kull darba I rikarigu din il-paġna, l-avviż
huwa ftakar kif ħafna drabi

563
00:25:58,380 --> 00:25:59,250
Stajt ilhom hemm.

564
00:25:59,250 --> 00:26:00,570
Ukoll, li mhux kollha li impressjonanti.

565
00:26:00,570 --> 00:26:03,140
Ejja biss tagħlaq dik tab,
u issa ejja mmorru lura għall

566
00:26:03,140 --> 00:26:07,860
http://localhost/counter.php.

567
00:26:07,860 --> 00:26:08,970
>> Oh, li interessanti.

568
00:26:08,970 --> 00:26:10,960
Hija xorta mfakkar, anki
għalkemm I għalqet il-tab.

569
00:26:10,960 --> 00:26:14,010
U franchement, jekk I qrib il-browser,
jekk ikun implimentat bl-aħjar mod, I

570
00:26:14,010 --> 00:26:18,950
xorta tista 'ftakar li dan l-utent huwa
li hu jew hi kien l-ewwel darba, u

571
00:26:18,950 --> 00:26:22,840
darba biss mmur menu Chrome, li
hawn fuq hija hawnhekk, u mur

572
00:26:22,840 --> 00:26:25,990
Istorja, u kklikkja Clear Browsing Data,
kif xi wħud minnkom jista 'jkollhom fil-

573
00:26:25,990 --> 00:26:33,050
passat, biss mbagħad cookies tiegħek
attwalment jitħassru matul web

574
00:26:33,050 --> 00:26:33,970
iżvilupp.

575
00:26:33,970 --> 00:26:35,340
>> Għalhekk, jekk immorru -

576
00:26:35,340 --> 00:26:37,080
ejja tagħlaq gedit here.

577
00:26:37,080 --> 00:26:38,910
U jekk immorru issa li dan il-fajl.

578
00:26:38,910 --> 00:26:44,210
Let me jmorru fil tagħna
vhosts / localhost / pubbliku, u let me do

579
00:26:44,210 --> 00:26:46,340
counter.php.

580
00:26:46,340 --> 00:26:48,350
Avviż li dan huwa pretty
programm sempliċi.

581
00:26:48,350 --> 00:26:50,250
Huwa website pjuttost sempliċi.

582
00:26:50,250 --> 00:26:51,770
>> Allura l-quċċata tal-fajl
huwa biss kummenti.

583
00:26:51,770 --> 00:26:54,930
Imma hawn xi linja ġdida li inti tista '
raw diġà fis-p sett sebgħa,

584
00:26:54,930 --> 00:26:56,000
session_start ().

585
00:26:56,000 --> 00:27:00,380
Din hija linja tal-kodiċi PHP li
essenzjalment jirrakkonta l-web server, jagħmlu

586
00:27:00,380 --> 00:27:03,400
żgur li timbru idejn u jagħmlu
żgur li tivverifika timbri idejn.

587
00:27:03,400 --> 00:27:06,810
Li kollox dik il-linja ma, u
ma kollha ta 'dak il-proċess għalina.

588
00:27:06,810 --> 00:27:09,510
Imbagħad avviż Stajt biss ltqajna
żewġ fergħat hawn.

589
00:27:09,510 --> 00:27:14,150
Jekk il-kjavi counter ġewwa ta 'dan
varjabbli globali speċjali msejħa

590
00:27:14,150 --> 00:27:18,010
$ _SESSION Huwa stabbilit - fi kliem ieħor,
jekk hemm xi valur hemmhekk -

591
00:27:18,010 --> 00:27:22,440
ejja nikseb dan u jaħżnu lokali
varjabbli imsejħa $ counter.

592
00:27:22,440 --> 00:27:27,000
Else, ejja tassenja $ counter
il-valur ta 'default ta '0.

593
00:27:27,000 --> 00:27:30,320
>> Issa hawn aspett wieħed ta 'PHP li l-
kemm barka u curse.

594
00:27:30,320 --> 00:27:32,080
PHP huwa ftit sloppy.

595
00:27:32,080 --> 00:27:35,160
Allura billi fis-C, dak li l-
ambitu tal-counter kienu

596
00:27:35,160 --> 00:27:36,725
jew hawn jew hawn?

597
00:27:36,725 --> 00:27:39,270

598
00:27:39,270 --> 00:27:41,690
>> Kienet tkun limitata
għal dawk braces kaboċċi.

599
00:27:41,690 --> 00:27:42,090
Raden liema?

600
00:27:42,090 --> 00:27:46,920
Fil PHP, dan jeżisti anke barra minn dawk
braces kaboċċi, hawn, u hawn,

601
00:27:46,920 --> 00:27:49,120
u hawn, u hawn, u
anke down hawn taħt.

602
00:27:49,120 --> 00:27:52,400
So I ngħid dan huwa barka fis-sens
li inti ma għandekx biex jaħsbu bħala

603
00:27:52,400 --> 00:27:54,070
hard kif għamilna ġimgħat ilu.

604
00:27:54,070 --> 00:27:56,880
Imma hija wkoll daqsxejn ta 'curse f'dak
ebda kwistjoni fejn inti tuża varjabbli

605
00:27:56,880 --> 00:28:00,020
PHP, għall-inqas fi programm bħal dan,
huwa globalment aċċessibbli għall-

606
00:28:00,020 --> 00:28:01,170
aħjar jew għall-agħar.

607
00:28:01,170 --> 00:28:06,130
Allura inti għandek iżomm f'moħħu issa li
varjabbli tiegħek ma jistgħux jiġu undefined.

608
00:28:06,130 --> 00:28:07,640
Inti jista 'jkollok definiti minnhom x'imkien ieħor.

609
00:28:07,640 --> 00:28:09,460
>> Imma dak li jien ser tagħmel finalment?

610
00:28:09,460 --> 00:28:13,160
Jien ser jaħżnu ġewwa ta 'dik globali
varjabbli bħala valur tal-

611
00:28:13,160 --> 00:28:17,060
counter ewlieni r-riżultat ta '
tagħmel counter plus 1.

612
00:28:17,060 --> 00:28:18,910
Allura dan huwa biss l-aritmetika
li ma l-

613
00:28:18,910 --> 00:28:20,590
incrementation 'dak counter.

614
00:28:20,590 --> 00:28:24,850
U l-fatt li jien ħażna li
valur lura fil hawn ifisser huwa li

615
00:28:24,850 --> 00:28:29,970
essenzjalment taġġorna d-database għall-
ftakar li 123456789 utent ilu

616
00:28:29,970 --> 00:28:31,010
hawn darbtejn.

617
00:28:31,010 --> 00:28:33,780
U meta I jagħmlu mill-ġdid il-ħin li jmiss I
rikarigu-paġna, li għaddej biex jiċċekkjaw

618
00:28:33,780 --> 00:28:36,710
timbru naħa tiegħi u jgħidu, oh,
123456789 utent għandu issa

619
00:28:36,710 --> 00:28:38,410
kien hawn tliet darbiet.

620
00:28:38,410 --> 00:28:43,390
>> U iva, liema lingwi PHP u simili
qed jagħmlu għalina hija li huma jidhru

621
00:28:43,390 --> 00:28:47,720
kif u fejn u għal kemm żmien
li żżomm il-valuri f'din speċjali

622
00:28:47,720 --> 00:28:48,830
superglobal.

623
00:28:48,830 --> 00:28:52,750
U dan superglobal-ħin li jmiss I
żur il-paġna huwa tip ta magically

624
00:28:52,750 --> 00:28:57,440
pre-popolati, mimlija bil-valuri li
kien hemm l-aħħar darba li tkun żaret,

625
00:28:57,440 --> 00:29:02,310
jekk dan kien it-tieni ilu, ġimgħa
ilu, jew fl-2013 u aħna qed issa jitkellem

626
00:29:02,310 --> 00:29:03,790
dwar 2015.

627
00:29:03,790 --> 00:29:07,600
PHP u l-web server jieħdu ħsieb
kollha ta 'dan għalik.

628
00:29:07,600 --> 00:29:08,850
>> UDJENZA: [inaudible].

629
00:29:08,850 --> 00:29:11,900

630
00:29:11,900 --> 00:29:15,760
>> DAVID Malan: elementi varjabbli fil PHP huma
essenzjalment dejjem globali sakemm inti

631
00:29:15,760 --> 00:29:18,400
jiddikjaraw lilhom ġewwa ta 'funzjoni,
u allura dawn huma lokali biex

632
00:29:18,400 --> 00:29:19,420
il-funzjoni biss.

633
00:29:19,420 --> 00:29:22,300
Imma għaliex stajt jkunux miktuba xi
funzjonijiet, huma issa effettivament

634
00:29:22,300 --> 00:29:25,090
globali matul fajl sħiħ tiegħi hawn.

635
00:29:25,090 --> 00:29:26,040
>> UDJENZA: Hemm mod
jagħmluhom lokali?

636
00:29:26,040 --> 00:29:28,470
>> DAVID Malan: Hemm xi
mod biex jagħmluhom lokali?

637
00:29:28,470 --> 00:29:30,680
Huwa biss billi tgeżwir minnhom fil-funzjonijiet.

638
00:29:30,680 --> 00:29:32,790
Li fl-aħħar verżjoni tad-
PHP, inti tista 'tagħmel dan ma'

639
00:29:32,790 --> 00:29:34,130
funzjoni anonimu.

640
00:29:34,130 --> 00:29:35,930
Iżda aktar fuq li fil-
kuntest ta 'JavaScript.

641
00:29:35,930 --> 00:29:37,260
Iżda l-risposta qasira hija le.

642
00:29:37,260 --> 00:29:40,888
A tweġiba hija iva itwal.

643
00:29:40,888 --> 00:29:42,380
Nizza.

644
00:29:42,380 --> 00:29:43,380
Mistoqsija tajba kwizz.

645
00:29:43,380 --> 00:29:43,930
Kull dritt.

646
00:29:43,930 --> 00:29:47,760
>> Allura fl-aħħarnett, il-paġna nnifisha hija
attwalment pjuttost sempliċi.

647
00:29:47,760 --> 00:29:51,470
Avviż li ladarba I ħruġ modalità PHP, recall
li dan kollu Jittieħed isfel

648
00:29:51,470 --> 00:29:53,700
hawn taħt huwa biss se tikseb bżiq
out prima għall-browser.

649
00:29:53,700 --> 00:29:57,050
Liema hija multa, minħabba I do jridu jibagħtu
l-utent xi HTML, imma jien ma jridux

650
00:29:57,050 --> 00:29:59,140
li dinamikament jaġġornaw dik HTML.

651
00:29:59,140 --> 00:30:03,930
U mod wieħed I tista 'tagħmel dan huwa li sort
ta 'malajr ħafna jinżel lura fis PHP

652
00:30:03,930 --> 00:30:07,730
modalità, jużaw open kwistjoni mark bracket
sinjal ugwali, u mbagħad output l-valur

653
00:30:07,730 --> 00:30:08,650
ta counter.

654
00:30:08,650 --> 00:30:12,360
>> Jew jekk dan jistenna ftit cryptic, dan
sinjal ugwali huwa attwalment biss ftit

655
00:30:12,360 --> 00:30:16,190
zokkor sintattika għal dan
printf ($ counter).

656
00:30:16,190 --> 00:30:19,160
Iżda franchement, li jinsab biss ftit ikrah
u ftit annoying għat-tip.

657
00:30:19,160 --> 00:30:23,660
Allura PHP ħafna nicely toffri din il-karatteristika
fejn inti tista 'biss jgħidu li aktar

658
00:30:23,660 --> 00:30:25,450
qosor fl-istess mod.

659
00:30:25,450 --> 00:30:26,940
>> Allura x'inhu għaddej taħt
il-barnuża?

660
00:30:26,940 --> 00:30:31,210
Ejja malajr nħarsu lejn in-netwerk
tab hawn għal counter.php.

661
00:30:31,210 --> 00:30:35,090
U let me imorru quddiem u l-ewwel
ejja ċar cookies tiegħek.

662
00:30:35,090 --> 00:30:38,670
Data browsing ċari Ejja peress
il-bidu ta 'żmien.

663
00:30:38,670 --> 00:30:39,680
Issa ejja mmorru lura minn hawn.

664
00:30:39,680 --> 00:30:41,340
Issa ejja rikarigu-paġna.

665
00:30:41,340 --> 00:30:42,170
U jien lura għal żero.

666
00:30:42,170 --> 00:30:44,810
Minħabba timbru naħa tiegħi kien maħsul,
I issa jiksbu cookie ġdid.

667
00:30:44,810 --> 00:30:48,780
>> Tabilħaqq jekk I tħares lejn il-tab netwerk u
tħares lejn headers rispons, avviż

668
00:30:48,780 --> 00:30:51,960
li l-appliance hija li jibgħat me
cookie li ismu huwa kemmxejn

669
00:30:51,960 --> 00:30:55,820
arbitrarju, iżda tip ta '
raġonevolment, PHPSESSID.

670
00:30:55,820 --> 00:30:58,440
U huwa jibghatni dan verament
numru bl-addoċċ big.

671
00:30:58,440 --> 00:30:59,440
Mhuwiex pjuttost numru.

672
00:30:59,440 --> 00:31:00,390
Huwa pjuttost mhux hexadecimal.

673
00:31:00,390 --> 00:31:03,600
Huwa xi tip ta 'spag alfanumeriku,
iżda preżumibbilment huwa każwali.

674
00:31:03,600 --> 00:31:06,830
U li huwa l-timbru idejn hekk biex
jitkellmu li jien jirreferu għall.

675
00:31:06,830 --> 00:31:11,960
>> Sadanittant jekk I ikklikkja rikarigu u mbagħad
ħarsa lejn din it-tieni linja għat-tieni tiegħi

676
00:31:11,960 --> 00:31:17,600
talba, avviż issa li t-talba tiegħi
headers jinkludu PHPSESSID ugwali dan,

677
00:31:17,600 --> 00:31:19,390
ma set-cookie, iżda biss cookie.

678
00:31:19,390 --> 00:31:22,950
U li l-preżentazzjoni browser tiegħi
ta 'timbru naħa tiegħi.

679
00:31:22,950 --> 00:31:28,820
>> Allura issa bħala teaser, u aħna ser nitkellmu aktar
dwar dan fil-ġimgħa jew hekk, imma

680
00:31:28,820 --> 00:31:31,590
b'liema mod il dan tagħmel inti
vulnerabbli, kont tiegħek Facebook

681
00:31:31,590 --> 00:31:34,137
vulnerabbli, u oħrajn bħal
kontijiet vulnerabbli?

682
00:31:34,137 --> 00:31:35,510
>> UDJENZA: Jekk xi ħadd ikollu cookie tiegħek.

683
00:31:35,510 --> 00:31:36,750
>> DAVID Malan: Yeah, jekk xi ħadd
għandha cookie tiegħek.

684
00:31:36,750 --> 00:31:39,920
I mean tassew, simili ħafna xi wħud minnkom
tista ippruvaw fil bħal klabb jew

685
00:31:39,920 --> 00:31:44,030
park ta 'divertiment, jekk inti tipprova xi ħaġa
bħal dan li kopja tal-boll, għalkemm

686
00:31:44,030 --> 00:31:47,560
lura fuq naħa ta 'persuna oħra,
u allura hu jew hi tippreżenta bħala

687
00:31:47,560 --> 00:31:53,250
tagħhom stess, jekk fil-fatt ma tfittex
identiċi, 123456789, allura l-web

688
00:31:53,250 --> 00:31:57,980
server li apparentament huwa biss se
fiduċja li dak l-utent huwa inti.

689
00:31:57,980 --> 00:32:01,450
>> U dan huwa tabilħaqq fundamentali
theddida kwalunkwe ħin li inti tuża cookies

690
00:32:01,450 --> 00:32:05,420
għaliex jekk xi ħadd biss spoofs hekk li
jitkellmu cookie tiegħek, figuri barra dak li

691
00:32:05,420 --> 00:32:08,660
hija, jew billi verament ikkupjar
billi tħares lejn il-kompjuter tiegħek

692
00:32:08,660 --> 00:32:09,890
u li jkunu simili, OK.

693
00:32:09,890 --> 00:32:14,520
Cookie David huwa JJ3JIK u oħrajn,
u mbagħad dawn qed intelliġenti biżżejjed biex tkun taf

694
00:32:14,520 --> 00:32:18,080
kif issolvi manwalment jibgħat dik
cookie minn browser jew minn

695
00:32:18,080 --> 00:32:22,350
programm huma jiktbu, dawn jistgħu totalment
log fis websajt kif inti.

696
00:32:22,350 --> 00:32:28,560
Mhuwiex li diffiċli li jippretendu li jkunu
xi ħadd ieħor sakemm aħna tirrevedi p-set

697
00:32:28,560 --> 00:32:30,790
tnejn, li introduċiet liema?

698
00:32:30,790 --> 00:32:32,065
>> UDJENZA: Kriptografika.

699
00:32:32,065 --> 00:32:33,860
>> DAVID Malan: A ftit
daqsxejn ta 'kriptografija.

700
00:32:33,860 --> 00:32:36,550
Kriptografija sempliċi, inqas fil-
standard edizzjoni, iżda kripto

701
00:32:36,550 --> 00:32:36,870
xorta.

702
00:32:36,870 --> 00:32:37,410
inqas.

703
00:32:37,410 --> 00:32:41,440
Għalhekk jirriżulta li jekk inti kriptaġġ kollha
dawn headers jużaw xi ħaġa li inti

704
00:32:41,440 --> 00:32:48,770
issa tista 'tkun taf aktar familjari bħala SSL,
socket layer, jew URLs https:/,

705
00:32:48,770 --> 00:32:51,890
allura kollha ta 'dawn affarijiet aħna kont qed
glancing fil huma attwalment encrypted,

706
00:32:51,890 --> 00:32:54,800
li jfisser li huwa simili inti
ma tistax taqra l timbru idejn.

707
00:32:54,800 --> 00:32:59,350
Biss facebook.com jista ', jew google.com,
jew f'dan il-każ, l-appliance jista '

708
00:32:59,350 --> 00:33:00,550
taqra li timbru idejn.

709
00:33:00,550 --> 00:33:04,020
>> Traġikament għalkemm, u għal darb'oħra, dan huwa
kollha wisq xierqa mal-għalf NSA

710
00:33:04,020 --> 00:33:06,410
l-aħħar, anki SSL huwa breakable.

711
00:33:06,410 --> 00:33:09,850
U huwa attwalment mhux li diffiċli
biex saħansitra xquq li encryption.

712
00:33:09,850 --> 00:33:12,040
Mhux tant mill-ikkrekkjar ta 'l-encryption,
iżda mill tricking l-

713
00:33:12,040 --> 00:33:15,720
browser fis decrypting
id-dejta qabel iż-żmien.

714
00:33:15,720 --> 00:33:17,880
Iżda għal darb'oħra, aħna ser inti tease
ma 'dik qabel twil.

715
00:33:17,880 --> 00:33:21,242
Għal issa, biss ikunu jibżgħu.

716
00:33:21,242 --> 00:33:23,070
Huwa traġikament tip ta 'veru.

717
00:33:23,070 --> 00:33:23,760
>> Kull dritt.

718
00:33:23,760 --> 00:33:27,910
Għalhekk, fejn ma dan issa leave us?

719
00:33:27,910 --> 00:33:29,010
Well, ejja tagħmel dan.

720
00:33:29,010 --> 00:33:31,790
Ejja jimxi 'l quddiem u tieħu quick
teaser qabel we jieħu pawża.

721
00:33:31,790 --> 00:33:33,790
U naħseb aħna ser linger ftit itwal
illum, imma aħna qed tmur biex adsa fis

722
00:33:33,790 --> 00:33:37,850
marka xi ħaġa ġdida u sexy, li se
iqabbduk l-aptit tiegħek għal saħansitra aktar.

723
00:33:37,850 --> 00:33:38,950
Allura dak hu l-teaser.

724
00:33:38,950 --> 00:33:41,520
>> Allura SQL, bdejna nitkellmu dwar
dejjem hekk qosor aħħar darba.

725
00:33:41,520 --> 00:33:44,670
Int ser verament tikseb idejk maħmuġin
ma 'xi ta' dan fil-p sett sebgħa.

726
00:33:44,670 --> 00:33:46,480
U f'termini laymans, dak ma SQL -

727
00:33:46,480 --> 00:33:47,110
S-Q-L -

728
00:33:47,110 --> 00:33:49,850
jagħmel għalik?

729
00:33:49,850 --> 00:33:50,310
X'inhu dan?

730
00:33:50,310 --> 00:33:51,546
Yeah.

731
00:33:51,546 --> 00:33:53,240
>> UDJENZA: Ejja inti aċċess għad-data.

732
00:33:53,240 --> 00:33:53,360
>> DAVID Malan: Yeah.

733
00:33:53,360 --> 00:33:55,120
Hija ejja inti aċċess għad-data
fid-database.

734
00:33:55,120 --> 00:33:56,710
Strutturat Mistoqsija Lingwa.

735
00:33:56,710 --> 00:33:59,890
U dan huwa essenzjalment
lingwa ta 'programmar.

736
00:33:59,890 --> 00:34:03,400
Hemm karatteristiċi ta 'dan li
aħna mhux se anki tuża fil-klassi.

737
00:34:03,400 --> 00:34:04,710
Imma int tista 'effettivament
jiddefinixxu l-funzjonijiet.

738
00:34:04,710 --> 00:34:06,870
Huma qed jissejjaħ maħżuna
proċeduri fl SQL.

739
00:34:06,870 --> 00:34:09,860
Iżda aħna ser jżommha pjuttost sempliċi u biss
użu minnha għal xi operazzjonijiet bażiċi

740
00:34:09,860 --> 00:34:14,320
bħall-għażla tad-data, li jdaħħal data,
aġġornament tad-data, u t-tħassir tad-data.

741
00:34:14,320 --> 00:34:17,400
>> U inti tista 'verament think ta' database,
bħal database SQL, biss bħala

742
00:34:17,400 --> 00:34:18,800
qed Microsoft Excel.

743
00:34:18,800 --> 00:34:21,989
Minħabba SQL tirreferi għal relazzjonali
database, fejn

744
00:34:21,989 --> 00:34:23,480
rigward ifisser biss tabelli.

745
00:34:23,480 --> 00:34:24,739
Ringieli u kolonni.

746
00:34:24,739 --> 00:34:27,929
Allura xi ħaġa li tista tpoġġi fil-spreadsheet
bħal dan jew Google Docs,

747
00:34:27,929 --> 00:34:32,460
inti tista 'tpoġġi fis-database SQL
billi jiddikjara tabella.

748
00:34:32,460 --> 00:34:34,800
>> Issa, kif taħseb li attwalment aċċess
dik l-informazzjoni?

749
00:34:34,800 --> 00:34:38,239
Ukoll, jikkmanda jew
mistoqsijiet bħal dan.

750
00:34:38,239 --> 00:34:40,199
TAGĦŻEL, DAĦĦAL, AĠĠORNAMENT, u ħassar.

751
00:34:40,199 --> 00:34:44,489
U għall-parti l-kbira, dawn huma l-
erba uniċi ingredjenti li ghandek bzonn biex

752
00:34:44,489 --> 00:34:47,370
tagħmel xi ħaġa pjuttost qawwi
fil-problema stabbiliti seba.

753
00:34:47,370 --> 00:34:49,940
>> Issa lura fil-ġurnata, inti fil-fatt
jinteraġixxu ma 'database fil-

754
00:34:49,940 --> 00:34:52,730
tieqa terminal iswed u abjad fil-
pront Teptip bħal dan.

755
00:34:52,730 --> 00:34:56,370
U d-database aħna qed taħdem fuq l-
apparat huwa msejjaħ MySQL, li hija

756
00:34:56,370 --> 00:34:58,560
magna database liberu u open source.

757
00:34:58,560 --> 00:35:02,240
Jekk inti Google u aqra l-Wikipedija
artikolu, inti ser tkun taf li l-isem huwa

758
00:35:02,240 --> 00:35:05,060
daqsxejn ta 'transizzjoni għal xi
verżjonijiet ta 'Linux.

759
00:35:05,060 --> 00:35:10,460
Database Maria huwa attwalment
furketta biex ngħidu hekk ta 'MySQL.

760
00:35:10,460 --> 00:35:12,740
>> Qasir Long storja, Oracle mixtrija MySQL.

761
00:35:12,740 --> 00:35:13,870
Oracle huwa kumpanija kbira.

762
00:35:13,870 --> 00:35:17,010
Nies ġew inkwetat li dan iwassal
m'għadhomx jibqgħu sors pjuttost miftuħ,

763
00:35:17,010 --> 00:35:20,930
għalhekk dan huwa biss kopja ta 'MySQL li l-
xorta b'xejn, għadu sors miftuħ, u

764
00:35:20,930 --> 00:35:23,550
installati fil Fedora Linux kontumaċja.

765
00:35:23,550 --> 00:35:26,130
>> Iżda din hija tip ta 'uġigħ fl-
għonq li jiffamiljarizzaw ma '

766
00:35:26,130 --> 00:35:27,310
database b'dan il-mod.

767
00:35:27,310 --> 00:35:30,560
Allura aħna jinkludu fl-appliance CS50
għodda sors miftuħ libera msejħa

768
00:35:30,560 --> 00:35:31,700
phpMyAdmin.

769
00:35:31,700 --> 00:35:33,940
Biss koinċidenza li
Huwa bil-miktub fil-PHP.

770
00:35:33,940 --> 00:35:36,450
M'hemm l-ebda fundamentali
bżonn għall PHP hawn.

771
00:35:36,450 --> 00:35:40,090
Iżda din hija biss għodda fuq l-internet li
aħna titniżżel b'xejn, installat fil-

772
00:35:40,090 --> 00:35:43,850
l-apparat, li jippermetti li jkollhom
grafika user interface li magħhom

773
00:35:43,850 --> 00:35:48,610
biex tesplora l-p sett seba database ma
li biex joħolqu databases ġodda,

774
00:35:48,610 --> 00:35:51,980
ngħid għal proġett finali tiegħek jekk youd
simili, u finalment joħolqu

775
00:35:51,980 --> 00:35:55,900
websajts dinamika bħal CS50 Finanzi
li jippermettu li inti mistoqsija data u

776
00:35:55,900 --> 00:35:58,140
jaġġornaw data dinamiku.

777
00:35:58,140 --> 00:36:01,420
>> Int mhux se jkollhom jużaw biss
fajl test sempliċi jew CSV.

778
00:36:01,420 --> 00:36:05,950
Inti tista 'attwalment jużaw database smart
programm sabiex inti tista 'twettaq b'mod aktar

779
00:36:05,950 --> 00:36:10,240
mistoqsijiet sofistikati milli sempliċiment qari
permezz kollox lineari.

780
00:36:10,240 --> 00:36:14,150
>> Allura per eżempju, dan huwa dak li aħna nagħtu
inti out tal-kaxxa għall-p sett sebgħa.

781
00:36:14,150 --> 00:36:18,280
Dan huwa tabella bi apparentament inqas
tliet kolonni, waħda minnhom hija

782
00:36:18,280 --> 00:36:21,450
username, li waħda minnhom hija hash,
u l-ieħor tagħhom huwa ID.

783
00:36:21,450 --> 00:36:26,200
>> Imma l-ħaġa interessanti, u biss biex
tease ħsieb wieħed hawn, username

784
00:36:26,200 --> 00:36:29,270
x'aktarx li huwa diġà unika, right?

785
00:36:29,270 --> 00:36:31,190
I mean, aktar xi website, jekk
għandek username, hemm

786
00:36:31,190 --> 00:36:32,370
ma jistax ikun f'żewġ Caesars.

787
00:36:32,370 --> 00:36:33,440
Ma jistax ikun hemm żewġ malans.

788
00:36:33,440 --> 00:36:34,950
Ma jistax ikun hemm żewġ jharvards.

789
00:36:34,950 --> 00:36:35,600
Unika tagħha.

790
00:36:35,600 --> 00:36:38,610
Inkella, dawn ma jkunux jafu liema
jharvard fatt hu.

791
00:36:38,610 --> 00:36:42,710
Allura x'jista 'jkun l-motivazzjoni għall wkoll
jkollhom tielet kolonna fuq ix-xellug

792
00:36:42,710 --> 00:36:46,970
hemm imsejħa ID, li qisu
numru li huwa simili unique?

793
00:36:46,970 --> 00:36:51,300
Iħoss żejda ftit
lili ewwel daqqa t'għajn.

794
00:36:51,300 --> 00:36:54,910
Għaliex jista 'jkun konvinċenti li jkollhom
mhux biss usernames uniku,

795
00:36:54,910 --> 00:36:56,837
iżda wkoll numri uniċi?

796
00:36:56,837 --> 00:36:59,460
>> UDJENZA: Huma jista 'jkollhom
l-istess password.

797
00:36:59,460 --> 00:37:01,720
>> DAVID Malan: Nies jista 'jkollhom
l-istess password, żgur.

798
00:37:01,720 --> 00:37:03,900
Dan jista 'assolutament jiġri.

799
00:37:03,900 --> 00:37:08,270
Iżda jekk dawn ikollhom din username uniku, I
jargumentaw li dan ma verament

800
00:37:08,270 --> 00:37:11,630
kwistjoni, għaliex jekk dawn it-tip fl tagħhom
username, I biss bżonn li jiċċekkja tagħhom

801
00:37:11,630 --> 00:37:15,060
password, hash tagħhom tiegħu.

802
00:37:15,060 --> 00:37:15,970
Għaliex inkella?

803
00:37:15,970 --> 00:37:17,950
>> UDJENZA: Faster tiftix.

804
00:37:17,950 --> 00:37:18,680
>> DAVID Malan: Faster tiftix.

805
00:37:18,680 --> 00:37:19,548
Għaliex?

806
00:37:19,548 --> 00:37:21,460
>> UDJENZA: ID hija waħda biss.

807
00:37:21,460 --> 00:37:24,040
>> DAVID Malan: ID huwa biss karattru wieħed,
jew biex ikunu aktar preċiżi, huwa numru,

808
00:37:24,040 --> 00:37:26,910
dan huwa probabbilment 32 bits
jew xi ħaġa bħal dik.

809
00:37:26,910 --> 00:37:30,270
Billi l-username, apparentement Jason
Hirschhorn sad hemm tip ta '

810
00:37:30,270 --> 00:37:33,900
ridiculously twil, u li għaddej biex
jieħdu me ħafna aktar ħin biex string

811
00:37:33,900 --> 00:37:40,910
iqabblu H-I-R-S-C-H-H-O-R-N, u forsi
a / 0 jew xi ħaġa bħal dik, sabiex

812
00:37:40,910 --> 00:37:45,100
tfittex up Jason, għall-kuntrarju biss
qal tagħti me numru utent tnejn.

813
00:37:45,100 --> 00:37:46,510
C'est 32 bits.

814
00:37:46,510 --> 00:37:48,550
Huwa INT waħda li
għandek biex titqabbel.

815
00:37:48,550 --> 00:37:52,150
U fil-fatt, dan huwa eżattament għaliex databases
tendenza li tassenja IDs uniċi li

816
00:37:52,150 --> 00:37:53,710
ringieli fihom.

817
00:37:53,710 --> 00:37:56,280
>> Issa liema tipi oħra tad-data hemm
minbarra INT u apparentement

818
00:37:56,280 --> 00:37:57,160
kordi bħal dan?

819
00:37:57,160 --> 00:37:59,700
Well, biex ikunu aktar xierqa,
Databases SQL, bħall-

820
00:37:59,700 --> 00:38:02,060
MySQL, għandhom kampijiet Char.

821
00:38:02,060 --> 00:38:05,320
U CHAR ftit misleadingly
mhuwiex CHAR wieħed.

822
00:38:05,320 --> 00:38:10,290
A qasam CHAR f 'database MySQL huwa
karattri wieħed jew aktar, imma hija

823
00:38:10,290 --> 00:38:11,780
numru fiss ta 'karattri.

824
00:38:11,780 --> 00:38:15,710
>> Għalhekk per eżempju, jekk I jmorru fuq biex
phpMyAdmin kif inti tista 'diġà, jew

825
00:38:15,710 --> 00:38:21,340
dalwaqt se problema stabbiliti seba ', u mmur
għad-database tiegħi, u biss għall-gost,

826
00:38:21,340 --> 00:38:25,700
ejja tinħoloq tabella ġdida msejħa
test bil biss żewġ kolonni.

827
00:38:25,700 --> 00:38:27,160
I ser mbagħad ikklikkja Mur.

828
00:38:27,160 --> 00:38:30,070
U dan se jsir pjuttost familjari,
speċjalment kif inti tinker

829
00:38:30,070 --> 00:38:31,130
madwar fuq tiegħek.

830
00:38:31,130 --> 00:38:34,140
Hawnhekk I tista 'tip ID joħolqu
tabella ġdida ta INT tip.

831
00:38:34,140 --> 00:38:37,770
Imma hawn I jista tip username li
jirrikreaw dik it-tabella preċedenti.

832
00:38:37,770 --> 00:38:40,700
U l-avviż I jkollhom mazz sħiħ
ta 'tipi li jagħżlu minn.

833
00:38:40,700 --> 00:38:43,610
>> U dan ukoll huwa għaliex phpMyAdmin
huwa tip ta 'sbieħ.

834
00:38:43,610 --> 00:38:46,770
Huwa tip ta 'awto-tagħlim fl-li inti
tista 'sempliċement tip ta' punt u kklikkja, u

835
00:38:46,770 --> 00:38:50,730
tħares lejn menus dropdown, u jiddeduċi minn
li dak poteri SQL jagħtik.

836
00:38:50,730 --> 00:38:54,090
>> U fil-fatt, jekk I jagħżlu CHAR, I imbagħad
għandek tispeċifika t-tul, jew kif

837
00:38:54,090 --> 00:38:55,940
Valuri ħafna, kemm Chars.

838
00:38:55,940 --> 00:39:00,090
Valuri hekk komuni ħafna huma affarijiet simili
255, iżda li ftit twil.

839
00:39:00,090 --> 00:39:02,250
Komunement huwa tmienja għal username.

840
00:39:02,250 --> 00:39:03,590
Imma dak li ftit żgħar dawn il-jiem.

841
00:39:03,590 --> 00:39:05,430
Allura din hija deċiżjoni disinn.

842
00:39:05,430 --> 00:39:08,630
Huwa 8 karattri max,
32, 255, 1,000?

843
00:39:08,630 --> 00:39:09,830
Huwa verament sa inti.

844
00:39:09,830 --> 00:39:12,350
Iżda qasam CHAR huwa numru fiss.

845
00:39:12,350 --> 00:39:16,420
Hekk jagħżlu ftit wisq u int tip ta '
invitat jekk inti tixtieq a username itwal.

846
00:39:16,420 --> 00:39:19,132
Agħżel wisq u x'hemm
l-isfel?

847
00:39:19,132 --> 00:39:20,820
>> UDJENZA: [inaudible].

848
00:39:20,820 --> 00:39:21,620
>> DAVID Malan: Huwa ħela.

849
00:39:21,620 --> 00:39:24,835
Eżatt bħal fil C, jekk għandek akbar
blokki ta 'memorja milli għandek bżonn, int

850
00:39:24,835 --> 00:39:27,190
biss ħela ta 'ħin u ħela ispazju.

851
00:39:27,190 --> 00:39:31,430
Allura bħala alternattiva, teżisti
Varchar, li jsolvi din il-problema billi

852
00:39:31,430 --> 00:39:36,390
trattament tul mhux bħala tul fiss,
iżda bħala tul massimu, u billi jintuża

853
00:39:36,390 --> 00:39:40,990
numru varjabbli ta 'Chars, li mbagħad
tendenza li jużaw biss bħala ħafna kif inti Chars

854
00:39:40,990 --> 00:39:42,710
attwalment ħtieġa.

855
00:39:42,710 --> 00:39:43,670
Ħsejjes li perfetta.

856
00:39:43,670 --> 00:39:45,640
>> Għaliex ma we jeħles mill-
Data CHAR tip allura?

857
00:39:45,640 --> 00:39:48,500
Liema jista 'jkun l-tnaqqis ta'
użu VARCHARs, li ħsejjes

858
00:39:48,500 --> 00:39:51,644
bħal din hija rebħa sbieħ?

859
00:39:51,644 --> 00:39:52,596
Yeah?

860
00:39:52,596 --> 00:39:53,846
>> UDJENZA: [inaudible].

861
00:39:53,846 --> 00:39:57,360

862
00:39:57,360 --> 00:39:57,790
>> DAVID Malan: OK, tajba.

863
00:39:57,790 --> 00:40:01,101
Mela jekk kollha tad-data tiegħek huwa l-istess
tul, x'inhu l-interess?

864
00:40:01,101 --> 00:40:05,250
>> UDJENZA: Minħabba int wasting
data billi tgħidilhom kollha.

865
00:40:05,250 --> 00:40:09,060
>> DAVID Malan: Mela jekk kollha tad-data tiegħek huwa
l-istess tul, għalkemm, nixtieq jargumentaw

866
00:40:09,060 --> 00:40:12,300
li tispeċifika t-tul massimu
fuq varchar mhi xejn differenti minn

867
00:40:12,300 --> 00:40:16,070
tispeċifika tul fiss fuq CHAR jekk
inti taf li hemm numru bil-quddiem.

868
00:40:16,070 --> 00:40:19,500
Iżda hemm tabilħaqq, u jien ser sort ta '
estratt mill din ir-risposta l-realtà

869
00:40:19,500 --> 00:40:22,610
li għad hemm max, li jista '
jkun annoying, speċjalment jekk inti

870
00:40:22,610 --> 00:40:25,920
jiltaqgħu isem ta 'persuna li l-
eċċezzjonalment twil li inti ma

871
00:40:25,920 --> 00:40:26,860
tantiċipa.

872
00:40:26,860 --> 00:40:31,420
U huwa wkoll ftit inqas effiċjenti
li attwalment tfittex fuq VARCHARs bħala

873
00:40:31,420 --> 00:40:35,620
kuntrarju Chars tiftix, speċjalment
għat-tabelli twil li jkunu lottijiet u

874
00:40:35,620 --> 00:40:36,510
lottijiet ta 'data.

875
00:40:36,510 --> 00:40:40,060
Allura hawnhekk ukoll, tematiku huwa għal darb'oħra
ebda għażla ovvja.

876
00:40:40,060 --> 00:40:42,870
>> Hekk biss li jtik sens ta 'l-oħra
tipi ta 'data li jistgħu jkunu ta' interess

877
00:40:42,870 --> 00:40:45,400
jew għal p-sett seba 'jew fil-
il-futur, hemm INT.

878
00:40:45,400 --> 00:40:47,270
Hemm BIGINT, li
huwa simili twil twil.

879
00:40:47,270 --> 00:40:48,880
Hemm tendenza li jkun 64 bits.

880
00:40:48,880 --> 00:40:51,640
Hemm deċimali, li tkun taf tara fil
il-problema sett, li huwa ferm

881
00:40:51,640 --> 00:40:55,300
cleaner tweġiba għall-problemi li għandna
ltaqgħu mal float u galleġġjanti

882
00:40:55,300 --> 00:40:55,980
punt impreċiżjoni.

883
00:40:55,980 --> 00:40:57,390
U allura hemm DateTime.

884
00:40:57,390 --> 00:41:01,530
Hemm litteralment a tip ta 'data li għandha
lill-dehra sena, xahar, jum,

885
00:41:01,530 --> 00:41:03,730
u siegħa, minuta, u t-tieni.

886
00:41:03,730 --> 00:41:07,470
>> Iżda databases SQL għandhom ukoll
affarijiet aħna ser sejħa indiċijiet.

887
00:41:07,470 --> 00:41:11,630
U indiċi hija xi ħaġa li inti
jispeċifika meta jinħoloq il-mejda li

888
00:41:11,630 --> 00:41:15,720
jagħmlu tfittxijiet u operazzjonijiet oħra
aktar effiċjenti.

889
00:41:15,720 --> 00:41:18,550
Speċifikament, hemm xi ħaġa imsejħa
l-indiċi PRIMARY li inti tista '

890
00:41:18,550 --> 00:41:19,440
tiddikjara kif ġej.

891
00:41:19,440 --> 00:41:22,330
>> Għamilna dan għalik ma 'l-
utenti tabella aħna nagħtuk.

892
00:41:22,330 --> 00:41:26,160
Imma avviż jekk jien kienu manwalment jerġgħu jinħolqu
-tabella hawn utenti tagħti

893
00:41:26,160 --> 00:41:27,110
dan l-isem ta 'l-utenti.

894
00:41:27,110 --> 00:41:28,125
I diġà speċifikat ID.

895
00:41:28,125 --> 00:41:29,330
I speċifikat INT.

896
00:41:29,330 --> 00:41:32,000
I speċifikat username ma
massimu 32 karattru.

897
00:41:32,000 --> 00:41:36,140
Imma jekk inżommu scrolling f'dan pjuttost
tieqa wiesgħa, avviż hemm

898
00:41:36,140 --> 00:41:38,260
mazz ta 'affarijiet oħra I jistgħu jispeċifikaw.

899
00:41:38,260 --> 00:41:40,950
>> Waħda, I tista 'tispeċifika l-attributi
simili, inti taf liema, dan

900
00:41:40,950 --> 00:41:42,190
INT għandhom ikunu iffirmati.

901
00:41:42,190 --> 00:41:45,510
Ma rridx numri negattivi,
hekk ejja jagħmluha mhux iffirmat.

902
00:41:45,510 --> 00:41:48,660
Null mhijiex rilevanti hawnhekk għaliex
I do jridu kull utent li

903
00:41:48,660 --> 00:41:49,640
jkollha numru uniku.

904
00:41:49,640 --> 00:41:50,830
Ma rridx li din tkun nulla.

905
00:41:50,830 --> 00:41:52,330
>> Iżda dan huwa interessanti.

906
00:41:52,330 --> 00:41:57,780
I tista 'tispeċifika li ID huwa jew il-
kodiċi primarju ta 'din id-database, jew huwa

907
00:41:57,780 --> 00:42:00,620
uniku, jew huwa indiċjati, jew full test.

908
00:42:00,620 --> 00:42:05,630
Allura għal skopijiet tal-lum, l-istorja twila
, mezzi PRIMARJI qosra li dan għandu

909
00:42:05,630 --> 00:42:10,570
jkun kemm kunċettwalment kif ukoll teknikament
il-qasam li nużaw biex unikament

910
00:42:10,570 --> 00:42:12,140
jidentifikaw l-utenti.

911
00:42:12,140 --> 00:42:16,140
>> Allura meta nħarsu up utenti, dan huwa tip
ta 'wegħda li tfittex lilhom aktar minn

912
00:42:16,140 --> 00:42:17,370
li identifikatur uniku.

913
00:42:17,370 --> 00:42:21,930
U d-database se tiżgura li jekk inti
jkollhom numru user 3, inti ma tistax

914
00:42:21,930 --> 00:42:25,400
fiżikament daħħal utent ieħor
bl-istess numru 3.

915
00:42:25,400 --> 00:42:28,380
Id-database se biss tirrifjuta
biex isalva bidliet tiegħek.

916
00:42:28,380 --> 00:42:32,310
Liema hija ħaġa tajba, għaliex inti tista '
tipproteġi ruħek mill yourself. awto

917
00:42:32,310 --> 00:42:34,270
>> Alternattivament, għal username.

918
00:42:34,270 --> 00:42:37,670
Allura l-tieni ringiela, recall,
huwa l-qasam username.

919
00:42:37,670 --> 00:42:41,860
Allura l-tieni ringiela hawnhekk huwa username,
kif għamilna fuq ix-xellug hemm.

920
00:42:41,860 --> 00:42:43,940
>> Allura x'iktar jista nixtieq li tispeċifika?

921
00:42:43,940 --> 00:42:47,840
Jien mhux permess, skond SQL,
li tispeċifika żewġ ċwievet primarja.

922
00:42:47,840 --> 00:42:50,750
inti tista 'tispeċifika ewlieni konġunta fejn inti
tħares lejn żewġ oqsma, iżda dawn ma jistgħux

923
00:42:50,750 --> 00:42:52,260
individwalment jkun ċwievet primarja.

924
00:42:52,260 --> 00:42:54,750
Allura dak hu barra mill-kwistjoni.

925
00:42:54,750 --> 00:42:56,040
So li jista nixtieq li jagħżlu?

926
00:42:56,040 --> 00:42:59,710
>> Well, UNIĊI huwa simili fl-ispirtu għal
kodiċi primarju fejn inti tispeċifika dan

927
00:42:59,710 --> 00:43:03,570
kamp għandha tkun unika, imma hija
mhux se jkun il-wieħed

928
00:43:03,570 --> 00:43:04,410
I użu l-ħin kollu.

929
00:43:04,410 --> 00:43:08,450
U aħna qed mhux se jużaw dan wieħed kull
il-ħin għal liema raġuni mill-ġdid?

930
00:43:08,450 --> 00:43:10,490
Huwa bil-mod potenzjalment jekk
huwa username twil.

931
00:43:10,490 --> 00:43:11,740
Huwa biss ħela ta 'ħin.

932
00:43:11,740 --> 00:43:16,140
>> INDIĊI, sadanittant, tispeċifika li huwa
mhux se tkun unika, imma nixtieq

933
00:43:16,140 --> 00:43:19,470
li taħdem magic tiegħek taħt il-
barnuża sabiex ikun aktar mgħaġġel għalija li

934
00:43:19,470 --> 00:43:21,420
tfittxija fuq il-qasam.

935
00:43:21,420 --> 00:43:23,320
Allura dan probabbilment mhuwiex rilevanti hawnhekk.

936
00:43:23,320 --> 00:43:26,500
Għal username, I d jargumentaw li
UNIQUE hija risposta tajba.

937
00:43:26,500 --> 00:43:31,200
Imma ejja ngħidu li għamilna utenti aktar
interessanti minn sempliċiment usernames,

938
00:43:31,200 --> 00:43:32,430
hashes, u numri tal-ID.

939
00:43:32,430 --> 00:43:33,860
X'jiġri jekk aħna taw nies ismijiet sħaħ?

940
00:43:33,860 --> 00:43:37,700
X'jiġri jekk aħna taw lilhom indirizzi
u data oħra dwar minnhom?

941
00:43:37,700 --> 00:43:43,360
>> Ukoll, jekk inti tispeċifika li kolonna a
database hija indiċjata, dan ifisser li

942
00:43:43,360 --> 00:43:47,730
MySQL, jew Oracle, jew kwalunkwe database
inti qed tuża, għandhom jaħdmu magic tagħha

943
00:43:47,730 --> 00:43:51,300
u l-użu xi tip ta 'data fancy
struttura bħal siġra, jew trie, jew

944
00:43:51,300 --> 00:43:55,940
tabella hash, jew xi ħaġa li jiggarantixxu
li meta inti tfittex għal data bl-użu

945
00:43:55,940 --> 00:43:58,150
jagħżlu fuq dak il-qasam partikolari -

946
00:43:58,150 --> 00:44:01,310
bħal urini kulħadd li
ħajjiet fuq Oxford Street.

947
00:44:01,310 --> 00:44:02,540
A mistoqsija bħal dik.

948
00:44:02,540 --> 00:44:06,250
Jekk għandek speċifikati minn qabel li
inti tixtieq indiċi fuq il-qasam, l-

949
00:44:06,250 --> 00:44:09,050
tfittxijiet se jkun ħafna, ħafna aktar mgħaġġla.

950
00:44:09,050 --> 00:44:12,090
>> Jekk inti ma jispeċifikawx indiċi, l-aħjar
inti tista 'tagħmel huwa tfittxija lineari jekk

951
00:44:12,090 --> 00:44:13,030
mhuwiex magħżula.

952
00:44:13,030 --> 00:44:16,220
Imma jekk inti tispeċifika INDIĊI, il-smart
persuni li għamlu l-database -

953
00:44:16,220 --> 00:44:19,340
nies bħalek li issa jafu siġar
u tipprova u tabelli hash -

954
00:44:19,340 --> 00:44:23,220
awtomatikament se jibni data bħal
istruttura RAM biex tiżgura li

955
00:44:23,220 --> 00:44:26,050
dawk tfittxijiet huma ħafna aktar mgħaġġla.

956
00:44:26,050 --> 00:44:29,660
>> Fulltext sadanittant huwa simili fl-ispirtu,
iżda tippermetti li tagħmel wildcard

957
00:44:29,660 --> 00:44:35,480
tfittxijiet, bħal urini kulħadd li
jgħix fil-toroq li jibdew bil-

958
00:44:35,480 --> 00:44:36,960
ittra O għal kwalunkwe raġuni.

959
00:44:36,960 --> 00:44:38,850
Tista 'tagħmel tfittxijiet wildcard
bħal dik.

960
00:44:38,850 --> 00:44:45,880
Or, affarijiet aktar konvinċenti simili juru
me kulħadd li għandu l-kelma -

961
00:44:45,880 --> 00:44:49,400
urini kulħadd li isimha jibda
ma 'ittra partikolari.

962
00:44:49,400 --> 00:44:51,880
Tista 'tfittex għal keywords
b'dan il-mod.

963
00:44:51,880 --> 00:44:52,630
Kull dritt.

964
00:44:52,630 --> 00:44:55,760
>> Allura, l-opportunitajiet ta 'disinn
hemm potenzjalment.

965
00:44:55,760 --> 00:44:57,740
Hemm oħrajn li jien ser
mewġa idejn tiegħi fuq.

966
00:44:57,740 --> 00:45:00,530
Jirriżulta li inti jista 'jkollhom
magni ta 'ħażna differenti.

967
00:45:00,530 --> 00:45:04,390
U dan huwa aktar arcane minn għandna bżonn
ċertament għal problema stabbiliti seba.

968
00:45:04,390 --> 00:45:06,920
Permezz ta 'default, inti guys qed jużaw
xi ħaġa imsejħa InnoDB.

969
00:45:06,920 --> 00:45:10,910
Int ser ikollok tara referenza ta 'din x'imkien
interface phpMyAdmin-aktar probabbli.

970
00:45:10,910 --> 00:45:14,130
Imma jafu li hemm disinn oħra
deċiżjonijiet li huma ta 'potenzjal

971
00:45:14,130 --> 00:45:18,030
interess jidħlu proġetti finali jekk
inti tagħmel fuq l-internet xi ħaġa.

972
00:45:18,030 --> 00:45:19,330
>> Imma ejja tagħmel dan.

973
00:45:19,330 --> 00:45:23,130
Ejja jimxi 'l quddiem u jdaħħlu dan fuq il-
screen bħala teaser għal storja

974
00:45:23,130 --> 00:45:26,330
jinvolvi inti, roommate,
u ħġieġ tal-ħalib.

975
00:45:26,330 --> 00:45:28,240
Ejja tagħti żewġ minuti
jew hekk break hawn.

976
00:45:28,240 --> 00:45:31,060
U jekk inti tista 'twaħħal madwar, ejja come
lura, tfittex ftit aktar fil SQL, u

977
00:45:31,060 --> 00:45:35,160
allura daqsxejn ta 'JavaScript ma
-p stabbiliti tmienja fil-moħħ.

978
00:45:35,160 --> 00:45:36,120
>> Kull dritt.

979
00:45:36,120 --> 00:45:40,420
Allura, ejja nikseb inti taħseb dwar
każ kantuniera li jistgħu faċilment jinqalgħu

980
00:45:40,420 --> 00:45:44,240
fil-kuntest ta 'użu ta' database, jew
franchement, anki bl-użu l-affarijiet dinjija reali

981
00:45:44,240 --> 00:45:46,280
bħal ATMs sabiex jiksbu flus.

982
00:45:46,280 --> 00:45:47,640
Allura hawnhekk friġġ.

983
00:45:47,640 --> 00:45:50,040
Ejja ngħidu li inti stajt ltqajna waħda wisq
dorm tiegħek jew dar tiegħek.

984
00:45:50,040 --> 00:45:54,990
U inti stajt ltqajna roommate waħda, u tnejn
int verament tixtieq ħalib per eżempju.

985
00:45:54,990 --> 00:45:57,210
>> Allura inti ġejjin dar mill-klassi jum wieħed.

986
00:45:57,210 --> 00:45:58,490
Hu jew hi għadu mhux lura.

987
00:45:58,490 --> 00:45:59,180
Inti tiftaħ il-fridge.

988
00:45:59,180 --> 00:46:00,870
Int verament tixtieq ħġieġ kbir ta 'ħalib.

989
00:46:00,870 --> 00:46:01,820
M'hemm l-ebda ħalib.

990
00:46:01,820 --> 00:46:02,920
Allura dak do you do?

991
00:46:02,920 --> 00:46:03,840
Inti qrib il-fridge.

992
00:46:03,840 --> 00:46:04,670
Inti grab ċwievet tiegħek.

993
00:46:04,670 --> 00:46:05,930
Inti tmur għall-kwadru.

994
00:46:05,930 --> 00:46:09,240
U ikollok fil-linja fil CVS lejn dawk
affarijiet checkout awto, li dejjem

995
00:46:09,240 --> 00:46:11,180
tieħu aktar milli fil-fatt
jkollhom kaxxiera.

996
00:46:11,180 --> 00:46:11,820
Xorta.

997
00:46:11,820 --> 00:46:15,490
>> Mela allura, sadanittant, dot dot dot, tiegħek
roommate jiġi dar u hu jew hi

998
00:46:15,490 --> 00:46:17,440
bl-istess mod għandha hankering
għal xi ħalib.

999
00:46:17,440 --> 00:46:20,380
Hekk hu jew hi tiftaħ il-fridge,
jistenna ġewwa, u oh, kkritikat.

1000
00:46:20,380 --> 00:46:21,160
Nru ħalib.

1001
00:46:21,160 --> 00:46:24,750
Hekk hu jew hi irjus, jiġri li jmorru
għall-CVS oħra, li kien biss

1002
00:46:24,750 --> 00:46:27,900
blokk bogħod għal xi raġuni, u hu jew
hi gets fil-linja li jixtru xi ħalib.

1003
00:46:27,900 --> 00:46:30,480
>> Sadanittant, inti ġejjin dar, hu jew
hi jiġi dar, u liema do

1004
00:46:30,480 --> 00:46:31,980
inti finalment ikollhom?

1005
00:46:31,980 --> 00:46:33,080
Ħalib darbtejn daqs.

1006
00:46:33,080 --> 00:46:34,620
Imma inti ma verament simili
ħalib li ħafna.

1007
00:46:34,620 --> 00:46:37,300
Allura issa għandek ħalib tant li issa
wieħed minnhom huwa biss se jmorru qarsa

1008
00:46:37,300 --> 00:46:37,820
eventwalment.

1009
00:46:37,820 --> 00:46:39,370
Allura din hija problema tassew ħżiena.

1010
00:46:39,370 --> 00:46:39,900
Dritt?

1011
00:46:39,900 --> 00:46:41,990
>> Allura dak li ġara?

1012
00:46:41,990 --> 00:46:44,810
Allura fundamentalment, dan huwa tip
ta 'eżempju redikoli.

1013
00:46:44,810 --> 00:46:48,580
Iżda taħt il-barnuża, dak li aħna kellna
jiġri hawnhekk huwa tnejn inti ċċekkjati

1014
00:46:48,580 --> 00:46:52,390
l-istat ta 'xi biċċa ta'
memorja, il-friġġ.

1015
00:46:52,390 --> 00:46:54,420
Tnejn inti ċċekkjati l-istat
ta 'xi varjabbli.

1016
00:46:54,420 --> 00:46:57,360
Inti kemm ġibdet konklużjoni
li inti mbagħad aġixxa fuq.

1017
00:46:57,360 --> 00:47:01,420
Iżda sfortunatament, filwaqt li roommate tiegħek
kien fil-maħżen, l-istat ta 'dik

1018
00:47:01,420 --> 00:47:05,670
varjabbli nbidlu, hu jew hi daħlet lura
u issa irid jibdel l-istat, iżda

1019
00:47:05,670 --> 00:47:07,480
huwa diġà ġie mibdul
fuq lilu jew lilha.

1020
00:47:07,480 --> 00:47:11,120
U ovvjament, hu jew hi ma jkollhom
marret għall-maħżen jekk dawn kienu jafu

1021
00:47:11,120 --> 00:47:13,010
li inti kienu diġà en route.

1022
00:47:13,010 --> 00:47:16,430
>> Allura fid-dinja reali, kif tista 'inti
jevitaw din il-problema, jekk wieħed jassumi għandek

1023
00:47:16,430 --> 00:47:18,940
fridge, għandek roommate,
u inti fil-fatt tixtieq ħalib?

1024
00:47:18,940 --> 00:47:19,760
>> UDJENZA: Nikkomunikaw.

1025
00:47:19,760 --> 00:47:20,580
>> DAVID Malan: Nikkomunikaw.

1026
00:47:20,580 --> 00:47:21,160
OK.

1027
00:47:21,160 --> 00:47:22,500
Imma kif tista 'inti tikkomunika?

1028
00:47:22,500 --> 00:47:23,990
>> UDJENZA: Ħalli nota.

1029
00:47:23,990 --> 00:47:25,480
>> DAVID Malan: Ħalli nota, right?

1030
00:47:25,480 --> 00:47:28,025
Dejjem iħallu nota, għall-
fannijiet ta 'l-ispettaklu.

1031
00:47:28,025 --> 00:47:31,580
Kull dritt, hekk dejjem iħallu nota, jew
tpoġġi verament bħal katnazz jew xi ħaġa

1032
00:47:31,580 --> 00:47:35,440
fuq il-friġġ li jżomm tiegħek
roommate milli jispezzjonaw l-istat ta '

1033
00:47:35,440 --> 00:47:36,540
dak il-varjabbli.

1034
00:47:36,540 --> 00:47:40,800
>> Issa, għaliex jista 'dan jiġi germane biex
problema stabbiliti seba ', jew biex ATMs.

1035
00:47:40,800 --> 00:47:46,780
Well, timmaġina dinja fi ATM fejn
inti tista 'tkun kapaċi li jmorru sa ATM

1036
00:47:46,780 --> 00:47:48,920
magna hawnhekk, u ATM ieħor hawnhekk.

1037
00:47:48,920 --> 00:47:50,680
U dan jiġri spiss.

1038
00:47:50,680 --> 00:47:54,150
U jissoponi kellek żewġ karti ATM,
li huwa possibbli li tinkiseb.

1039
00:47:54,150 --> 00:47:57,420
U inti log fis-żewġ magni
effettivemnt simultanjament, nisperaw

1040
00:47:57,420 --> 00:47:58,660
filwaqt li qed ifittxu l-ebda waħda.

1041
00:47:58,660 --> 00:48:01,260
U allura inti tip PIN tiegħek
bejn wieħed u ieħor fl-istess ħin.

1042
00:48:01,260 --> 00:48:06,280
U mbagħad inti tagħmel mistoqsija bilanċ
biex tara kemm flus ikollok.

1043
00:48:06,280 --> 00:48:08,920
U ejja ngħidu li għandek $ 100
jitħalla fil-kont tiegħek.

1044
00:48:08,920 --> 00:48:13,310
Allura essenzjalment simultanjament, inti
jgħidu wieħed, żero, żero, jidħol.

1045
00:48:13,310 --> 00:48:16,000
U inti nisperaw tikseb lura xi flus.

1046
00:48:16,000 --> 00:48:18,440
>> Imma kemm flus tista 'tikseb lura?

1047
00:48:18,440 --> 00:48:21,710
Issa kompjuters fl-aħħar tal-ġurnata,
speċjalment jekk dawn qed nitkellmu

1048
00:48:21,710 --> 00:48:27,360
servers, mhux bilfors tagħmel affarijiet
fl-ordni li mistenni.

1049
00:48:27,360 --> 00:48:30,860
>> Allura jissoponi x'jiġri, minħabba
kwalunkwe netwerk kwistjonijiet veloċità hemmhekk

1050
00:48:30,860 --> 00:48:34,530
huma, jew kwistjonijiet CPU hemm, jew
xi ħaġa bħal dik, jissoponi li l-

1051
00:48:34,530 --> 00:48:38,530
ewwel ATM kontrolli bilanċ u tiegħek
jara, oh, din il-persuna għandha $ 100.

1052
00:48:38,530 --> 00:48:41,840
Iżda mbagħad gets distratt għaliex forsi
backup qed jiġri u għalhekk huwa

1053
00:48:41,840 --> 00:48:42,500
tmajna.

1054
00:48:42,500 --> 00:48:45,080
Jew forsi waqt verifika, in-netwerk
konnessjoni ltqajna ftit aktar bil-mod minħabba

1055
00:48:45,080 --> 00:48:45,910
dan jiġri biss.

1056
00:48:45,910 --> 00:48:47,100
Huma qed mezzi fiżiċi.

1057
00:48:47,100 --> 00:48:49,330
Allura sadanittant, it-tieni ATM huwa
tistaqsi l-istess kwistjoni.

1058
00:48:49,330 --> 00:48:53,030
Kemm flus ma David jkollhom?
$ 100 huwa l-risposta.

1059
00:48:53,030 --> 00:48:58,930
Iżda minħabba l-ewwel ATM għadha ma
bagħat il-messaġġ naqqas $ 100, kemm

1060
00:48:58,930 --> 00:49:03,000
ATMs kienu spezzjonati kaxxa-forti tal-bank,
jaraw hemm $ 100 hemm, u issa

1061
00:49:03,000 --> 00:49:07,160
kemm magni potenzjalment huma
se bżiq risposta.

1062
00:49:07,160 --> 00:49:12,240
>> Issa, dan huwa kbir għalik f'xi sens
jekk dak il-bank ma finalment

1063
00:49:12,240 --> 00:49:17,200
qed jibdlu l-ammont għal nieqes 100 minn
iffissar tal-varjabbli daqs tiegħek

1064
00:49:17,200 --> 00:49:21,570
Kont tal-Bank ugwali għal 0, kuntrarju
biex tagħmel minus 100.

1065
00:49:21,570 --> 00:49:24,410
Issa fl-agħar każ għall-bank -

1066
00:49:24,410 --> 00:49:27,470
jew fl-aħjar għall-bank, sadanittant,
dawn jagħtu inti $ 200, u

1067
00:49:27,470 --> 00:49:31,690
kont bankarju tiegħek issa turi negattiv
$ 100, li verament ma

1068
00:49:31,690 --> 00:49:32,950
jibbenefikaw inti fil-livelli kollha.

1069
00:49:32,950 --> 00:49:36,500
Imma l-punt hu li din ir-razza
kundizzjoni għal żewġ roommates jkollna

1070
00:49:36,500 --> 00:49:40,660
ħalib, jew għal żewġ ATMs jippruvaw jiksbu l-flus
u jibdlu l-istat tal-kaxxa-forti

1071
00:49:40,660 --> 00:49:44,510
fl-istess ħin teżisti ebda
darba li inti għandek database.

1072
00:49:44,510 --> 00:49:48,290
>> Issa fil-problema stabbiliti seba ', din il-kwistjoni
tqum fis-sens li jekk tixtri

1073
00:49:48,290 --> 00:49:52,110
sehem ta 'Facebook istokk, u mbagħad għal
eżempju inti tixtri tieni sehem ta '

1074
00:49:52,110 --> 00:49:55,160
Facebook istokk, inti għandek bżonn tagħmel
deċiżjoni bħala l-programmer.

1075
00:49:55,160 --> 00:49:58,710
Sabiex tiddeċiedi kif biex jaġġornaw il-
database, odds huma inti qed tmur għall-

1076
00:49:58,710 --> 00:50:02,250
jkollhom ringiela waħda għal dak l-istokk, u dan
huwa mod wieħed biex jimplimentawha.

1077
00:50:02,250 --> 00:50:06,640
U int se jkollhom sehem wieħed ta '
FB, li hija simbolu ticker istokk tagħhom

1078
00:50:06,640 --> 00:50:10,120
għal dan username, jew dan l-utent
ID, l-identifikatur uniku.

1079
00:50:10,120 --> 00:50:12,340
>> Iżda l-istess storja jista 'jiġri hawn.

1080
00:50:12,340 --> 00:50:15,800
Jekk inti tagħmel TAGĦŻEL fil SQL, kif tkun taf tara
fil-problema sett seba meta tara,

1081
00:50:15,800 --> 00:50:18,460
oh, David għandu sehem wieħed
ta 'Facebook istokk.

1082
00:50:18,460 --> 00:50:23,240
Let me issa tbiddel dan li hemm żewġ ishma,
minħabba li huwa jixtieq jixtri

1083
00:50:23,240 --> 00:50:24,120
tieni sehem.

1084
00:50:24,120 --> 00:50:27,860
Iżda jissoponi David attwalment kellu żewġ
twieqi browser miftuħa, jew jissoponi li

1085
00:50:27,860 --> 00:50:32,150
huwa kont konġunt ma 'żewġ konjuġi,
u tnejn minnhom qed jippruvaw biex iwettqu

1086
00:50:32,150 --> 00:50:36,770
l-istess operazzjoni, hemm, wisq, il-
jeżisti potenzjal għal deċiżjoni biex tkun

1087
00:50:36,770 --> 00:50:39,670
imsejsa fuq il-preċedenti
istat tad-dinja -

1088
00:50:39,670 --> 00:50:41,290
il-kont għandu sehem wieħed -

1089
00:50:41,290 --> 00:50:45,630
u kemm nies, jew it-tnejn servers, issa
jippruvaw jgħidu inkrement li żewġ ishma.

1090
00:50:45,630 --> 00:50:49,020
Iżda f'dan il-każ, inti jista 'jkollok mitluba
me flus kemm għall-ishma, iżda

1091
00:50:49,020 --> 00:50:50,830
jiżdied biss dak iż-żmien wieħed.

1092
00:50:50,830 --> 00:50:54,730
>> Għalhekk fil-qosor, il-problema fundamentali
hawnhekk, kif ma 'l-Joke dwar jħallu

1093
00:50:54,730 --> 00:50:58,750
jinnota, jew it-tqegħid katnazz fuqha, huwa
jekk żewġ persuni, jew żewġ ħjut -

1094
00:50:58,750 --> 00:50:59,930
Think lura għall-bidu -

1095
00:50:59,930 --> 00:51:03,220
tista 'tispezzjona l-istat ta' xi varjabbli
u mbagħad jipprova jbiddel dak il-varjabbli,

1096
00:51:03,220 --> 00:51:07,950
iżda dawn iż-żewġ affarijiet ma jiġri fil-
istess ħin, iżda jistgħu jiksbu interrotta

1097
00:51:07,950 --> 00:51:11,500
minn affarijiet oħra jiġri, data tista '
jsibu rwieħhom stat ħafna stramb.

1098
00:51:11,500 --> 00:51:15,450
U inti tista 'tibbenefika jew inti jista' jbati
fis-sens ta 'l-eżempju flus.

1099
00:51:15,450 --> 00:51:18,110
>> Għalhekk fl problema stabbiliti seba ', aħna nagħtuk
din il-linja waħda tal-kodiċi, li fit-

1100
00:51:18,110 --> 00:51:21,000
storja qasira, issolvi din
problema MySQL.

1101
00:51:21,000 --> 00:51:24,950
Din l-istruzzjoni twil ħafna li ma
anki tajbin fuq linja waħda fuq l-

1102
00:51:24,950 --> 00:51:30,370
iskrin hawn jiżgura li operazzjoni tiegħek
huwa dak li sejjaħ atomika.

1103
00:51:30,370 --> 00:51:33,720
Dan kollu jiġri f'daqqa, jew
ma jiġri fil-livelli kollha.

1104
00:51:33,720 --> 00:51:37,530
Din il-frażi twil ħafna ma tistax
nikseb interrott parzjalment.

1105
00:51:37,530 --> 00:51:39,840
>> U dak li ma huwa litteralment
dak li jgħid.

1106
00:51:39,840 --> 00:51:44,200
Daħħal fis xi tabella li ġej
tliet oqsma dawk il-valuri speċifiċi,

1107
00:51:44,200 --> 00:51:47,280
iżda fuq duplikat ewlenin,
ma tagħmel daħħal.

1108
00:51:47,280 --> 00:51:48,280
Do aġġornament.

1109
00:51:48,280 --> 00:51:52,450
Allura dan huwa simili tagħmel TAGĦŻEL u
DAĦĦAL biex ngħidu hekk fl-istess ħin.

1110
00:51:52,450 --> 00:51:55,150
U dak huwa l-muftieħ li probabbilment
tkun riferita hawn?

1111
00:51:55,150 --> 00:51:58,300

1112
00:51:58,300 --> 00:52:01,380
>> Jirriżulta, u tkun taf tara dan fil-
problema stabbiliti spec Seba, għaliex

1113
00:52:01,380 --> 00:52:06,040
konna dikjarat li jkun hemm ċavetta unika
fuq din it-tabella partikolari b'mod li

1114
00:52:06,040 --> 00:52:08,480
ma jistax ikollok ringieli multipli
għall-istess utent ma 'l-

1115
00:52:08,480 --> 00:52:10,150
istess Penny istokk simbolu -

1116
00:52:10,150 --> 00:52:13,780
f'dan l-eżempju hawn, DVN.V hija
stokk Penny iblah li aħna

1117
00:52:13,780 --> 00:52:14,980
jirreferu fit-spec.

1118
00:52:14,980 --> 00:52:17,860
Għaliex aħna ħadthom ddikjarat li hu uniku,
dak li dan ifisser huwa li jekk inti

1119
00:52:17,860 --> 00:52:23,580
jippruvaw daħħal ringiela duplikat, int
minflok ser taġġorna mingħajr

1120
00:52:23,580 --> 00:52:27,020
ħaddieħor jkollhom iċ-ċans għall-bidla
l-istat tad-dinja jew.

1121
00:52:27,020 --> 00:52:29,400
Għalhekk fil-qosor, dan jiżgura
affarijiet huma atomika.

1122
00:52:29,400 --> 00:52:32,530
>> B'mod aktar ġenerali għalkemm, databases
bħal MySQL -

1123
00:52:32,530 --> 00:52:35,460
u inti m'għandekx bżonn din il-karatteristika għall-
p-sett seba ', iżda żżomm f'moħħha għal

1124
00:52:35,460 --> 00:52:36,200
il-futur -

1125
00:52:36,200 --> 00:52:38,870
appoġġ liema huma msejħa tranżazzjonijiet,
fejn inti tista 'tgħid

1126
00:52:38,870 --> 00:52:40,990
START transazzjoni litteralment.

1127
00:52:40,990 --> 00:52:43,270
Tista 'mbagħad tesegwixxi
żewġ dikjarazzjonijiet SQL.

1128
00:52:43,270 --> 00:52:45,710
U dikjarazzjoni SQL, kif tkun taf tara
fil-p stabbiliti seba ', jistenna ftit

1129
00:52:45,710 --> 00:52:46,750
xi ħaġa bħal din.

1130
00:52:46,750 --> 00:52:48,820
Taġġorna imsejħa kont tabella.

1131
00:52:48,820 --> 00:52:52,550
Issettja l-kolonna bilanċ ugwali għal dak kollu li
il-kolonna bilanċ bħalissa

1132
00:52:52,550 --> 00:52:57,280
huwa nieqes 1,000 fejn l-għadd, il-
numru tal-kont, bħall-user ID,

1133
00:52:57,280 --> 00:53:00,830
ugwali 2, u mbagħad taġġorna
kont dot dot dot.

1134
00:53:00,830 --> 00:53:04,350
>> Allura f'termini laymans, liema do dawn iż-żewġ
mistoqsijiet jidhru li huma jagħmlu fil-

1135
00:53:04,350 --> 00:53:05,840
sens dinja reali tal-banek?

1136
00:53:05,840 --> 00:53:07,440
>> UDJENZA: trasferiment għal iffrankar.

1137
00:53:07,440 --> 00:53:08,020
>> DAVID Malan: Eżattament.

1138
00:53:08,020 --> 00:53:10,470
Trasferiment ta 'fondi minn
kont għall-ieħor.

1139
00:53:10,470 --> 00:53:14,400
U dan huwa eżempju ieħor fejn int
verament irridu dawn iż-żewġ affarijiet li jiġri

1140
00:53:14,400 --> 00:53:15,570
jew le jiġri.

1141
00:53:15,570 --> 00:53:18,880
Inti ma tridx xi ħaġa li jiksbu fil-
nofs minnhom u potenzjalment mess up

1142
00:53:18,880 --> 00:53:22,220
l-matematika, jew mess up kemm
flus għandek, jew kemm

1143
00:53:22,220 --> 00:53:23,170
flus il-bank ikollu.

1144
00:53:23,170 --> 00:53:26,890
Allura x'hemm verament sbieħ dwar transazzjonijiet
fil MySQL hija li, u

1145
00:53:26,890 --> 00:53:30,160
databases b'mod aktar ġenerali, huwa li dawn
u nies intelliġenti li ħadthom implimentati

1146
00:53:30,160 --> 00:53:33,670
dawn il-karatteristiċi figura kif jagħmlu
żgur li kemm ta 'dawk l-affarijiet jiġri

1147
00:53:33,670 --> 00:53:35,120
jew xejn.

1148
00:53:35,120 --> 00:53:38,580
>> U jekk int verament jaspiraw li jagħmlu
websajt li użaw minn nies fuq

1149
00:53:38,580 --> 00:53:41,490
kampus, nies fid-dinja reali, tagħmel
xi ħaġa fis-sens istartjar,

1150
00:53:41,490 --> 00:53:43,300
dawn huma t-tipi ta '
deċiżjonijiet tad-disinn li

1151
00:53:43,300 --> 00:53:45,020
isiru dejjem hekk importanti.

1152
00:53:45,020 --> 00:53:48,240
Inkella, inti jibdew jitilfu data, jitilfu
utenti, jew fl-agħar każ bħala

1153
00:53:48,240 --> 00:53:51,800
Rajna hawn, potenzjalment
jitilfu l-flus.

1154
00:53:51,800 --> 00:53:56,180
Għalhekk għal darb'oħra, aktar fuq li fil-problema stabbiliti
seba ', kif ukoll forsi għal xi wħud

1155
00:53:56,180 --> 00:53:57,530
inti fil-proġetti finali.

1156
00:53:57,530 --> 00:54:01,870
>> Mela ejja bidla li stampa kellna
mument ilu biss f'waħda aktar mod.

1157
00:54:01,870 --> 00:54:04,070
So let me attwalment tara jekk I jistgħu -

1158
00:54:04,070 --> 00:54:06,030
Nope, li marret.

1159
00:54:06,030 --> 00:54:06,690
Hemm hu.

1160
00:54:06,690 --> 00:54:09,020
>> Allura dan huwa fejn aħna jitħalla aħħar darba.

1161
00:54:09,020 --> 00:54:12,390
U jirriżulta aħna qed tmur biex toss
ħaġ'oħra fis-taħlita hawn -

1162
00:54:12,390 --> 00:54:14,510
lingwa imsejħa JavaScript.

1163
00:54:14,510 --> 00:54:18,060
Allura JavaScript fatt jaqbilx effettivament
fil din il-biċċa -

1164
00:54:18,060 --> 00:54:22,086
u jien ma pjuttost jħallu spazju biżżejjed,
għalhekk dan mhux issa li l-iskala.

1165
00:54:22,086 --> 00:54:23,900
OK, dan huwa verament pathetic.

1166
00:54:23,900 --> 00:54:27,075
OK, b'tali mod li JavaScript.

1167
00:54:27,075 --> 00:54:27,340
Kull dritt.

1168
00:54:27,340 --> 00:54:28,760
Ninsab verament tagħmel dan disservice.

1169
00:54:28,760 --> 00:54:29,390
Kull dritt.

1170
00:54:29,390 --> 00:54:34,790
>> Allura JavaScript huwa programmar ieħor
lingwa, u l-aħħar tagħna, Jekk dan jgħin

1171
00:54:34,790 --> 00:54:37,770
jassigurhom li hemm Ma tantx aktar
mill-idranti tan-nirien hawn.

1172
00:54:37,770 --> 00:54:41,100
Allura JavaScript huwa wkoll interpretat
lingwa, li jfisser li inti ma

1173
00:54:41,100 --> 00:54:42,670
josservawha fis żerijiet u dawk.

1174
00:54:42,670 --> 00:54:43,690
Inti biss run.

1175
00:54:43,690 --> 00:54:47,680
Imma x'hemm fundamentalment differenti ma
JavaScript normalment huwa li inti

1176
00:54:47,680 --> 00:54:49,815
ma run fuq web server tiegħek.

1177
00:54:49,815 --> 00:54:52,570
Hija ma jiksbu run fil-
appliance per se.

1178
00:54:52,570 --> 00:54:57,490
Pjuttost, jiġrilha jitniżżel minn utent
permezz HTTP fil-browser tagħhom -

1179
00:54:57,490 --> 00:55:00,260
Chrome, Safari, Internet Explorer,
Firefox, ikun x'ikun -

1180
00:55:00,260 --> 00:55:03,860
u huwa l-browser li tesegwixxi dan
partikolari lingwa ta 'programmar.

1181
00:55:03,860 --> 00:55:08,000
>> Allura biex tkun ċara, PHP s'issa kien
esegwiti jew fil-linja tal-kmand fl

1182
00:55:08,000 --> 00:55:11,290
iswed u abjad tieqa tagħna, fuq server
bħall-appliance, kompjuter

1183
00:55:11,290 --> 00:55:14,490
bħall-appliance, jew huwa kien
eżegwiti minn web server

1184
00:55:14,490 --> 00:55:15,860
taħdem fuq il-kompjuter.

1185
00:55:15,860 --> 00:55:20,490
Iżda l-tema hawnhekk hija li PHP s'issa
tkun ġiet eżegwita server-ġenb, hekk

1186
00:55:20,490 --> 00:55:24,820
l-utent u browser l-utent
qatt ma jara linja tal-kodiċi PHP.

1187
00:55:24,820 --> 00:55:28,530
>> Fil-fatt, jekk inti qatt tiftaħ browser għall-
website tiegħek jew ieħor u int

1188
00:55:28,530 --> 00:55:32,400
attwalment ara kodiċi PHP fil tieqa tiegħek,
xi ħadd invitat up.

1189
00:55:32,400 --> 00:55:34,950
Għaliex mhuwiex maħsub li jkun
mibgħuta lil browser direttament.

1190
00:55:34,950 --> 00:55:38,150
Huwa suppost li jiġi eżegwit u mdawwar
fis xi ħaġa bħal HTML.

1191
00:55:38,150 --> 00:55:40,120
>> Iżda JavaScript huwa essenzjalment
l-oppost.

1192
00:55:40,120 --> 00:55:44,350
Huwa maħsub biex jitmexxew tipikament ġewwa
tal-browser window ta 'utent.

1193
00:55:44,350 --> 00:55:46,840
U liema tipi ta 'websajts użu
JavaScript allura dawn il-jiem?

1194
00:55:46,840 --> 00:55:49,640

1195
00:55:49,640 --> 00:55:52,180
>> Bħal litteralment kull website popolari.

1196
00:55:52,180 --> 00:55:55,430
Kull websajt li inti guys probabbilment
użu ta 'kuljum jużaw JavaScript għall-

1197
00:55:55,430 --> 00:55:57,330
sempliċi u anke l-
karatteristiċi sexiest.

1198
00:55:57,330 --> 00:55:59,800
>> Allura xi ħaġa bħal Facebook
Chat jekk tuża dan.

1199
00:55:59,800 --> 00:56:01,040
Kif ma li attwalment jaħdmu?

1200
00:56:01,040 --> 00:56:05,090
Well s'issa, kollha ta 'l-għalf konna
isir bl HTML u PHP jassumi li

1201
00:56:05,090 --> 00:56:08,750
inti pull up a URL, u inti hit Ikteb,
u tara xi kontenut HTML.

1202
00:56:08,750 --> 00:56:11,970
U inti ikklikkja l-link, li tbiddel il-
URL, bidliet il-paġna, u rikarigi

1203
00:56:11,970 --> 00:56:12,740
xi kontenut ġdid.

1204
00:56:12,740 --> 00:56:16,340
Ikklikkja URL ieħor jew jissottomettu formola, inti
nikseb whisked għal paġna oħra u

1205
00:56:16,340 --> 00:56:17,420
tara xi kontenut ġdid.

1206
00:56:17,420 --> 00:56:22,710
>> Iżda bl-użu xi ħaġa bħal Facebook Chat,
jew Gchat, jew Google Maps, rarament

1207
00:56:22,710 --> 00:56:27,350
ma l-paġna kollha jġedded tali li
inti tara l-iskrin abjad mumentarjament u

1208
00:56:27,350 --> 00:56:28,470
imbagħad kontenut ġdid.

1209
00:56:28,470 --> 00:56:32,610
Pjuttost, paġni tal-web llum huma dinamikament
jkollna aġġornati mill-ġdid u

1210
00:56:32,610 --> 00:56:35,570
ġdid u għal darb'oħra kull tip
tal wara l-kwinti.

1211
00:56:35,570 --> 00:56:38,560
U jirriżulta li meta inti tagħmel tmur
xi ħaġa bħal Facebook, jew Gchat,

1212
00:56:38,560 --> 00:56:43,050
jew Gmail, u l-aġġornamenti paġna
awtomatikament mingħajr tagħbija mill-ġdid il-

1213
00:56:43,050 --> 00:56:47,630
iskrin kollu, dak li ġara huwa li
browser tiegħek għamel tip ta segretament

1214
00:56:47,630 --> 00:56:49,410
talbiet addizzjonali HTTP -

1215
00:56:49,410 --> 00:56:52,740
mhux għall-paġni web kollu, imma biss għall-
biċċiet ftit ta 'data, bħall-

1216
00:56:52,740 --> 00:56:55,740
messaġġ instant li l-ħabib tiegħek biss
bagħtitlek, jew l-istatus aġġornament li

1217
00:56:55,740 --> 00:56:58,210
xi ħadd biss bagħtitlek, jew l-tweet
li xi ħadd biss mibgħuta.

1218
00:56:58,210 --> 00:57:02,120
Huwa biss tagħmel talbiet ftit għal
data, u mbagħad jużaw JavaScript, dan

1219
00:57:02,120 --> 00:57:06,370
programmazzjoni lingwa, li jibdlu dak
il-paġna web qisu mingħajr il-

1220
00:57:06,370 --> 00:57:09,860
server tgħin, mingħajr il-server
tiġġenera dak HTML.

1221
00:57:09,860 --> 00:57:13,820
>> Għalhekk fil-qosor, JavaScript jistgħu jintużaw mbagħad
li mhux biss jġibu data ġodda minn

1222
00:57:13,820 --> 00:57:16,750
l-server mingħajr tagħbija mill-ġdid kollu kemm hu
paġna jew sottomissjoni ta 'formola.

1223
00:57:16,750 --> 00:57:20,060
Hija tista 'tintuża wkoll għall-bidla
l-hekk imsejħa DOM -

1224
00:57:20,060 --> 00:57:21,520
mudell tad-dokument oġġett -

1225
00:57:21,520 --> 00:57:24,620
li huwa biss il-mod fancy għall
qal il-siġra tal-HTML

1226
00:57:24,620 --> 00:57:26,220
li rajna aħħar darba.

1227
00:57:26,220 --> 00:57:31,640
>> Allura biex iserraħ ras, JavaScript huwa
sintattikament daqshekk simili li C kif ukoll.

1228
00:57:31,640 --> 00:57:32,820
M'hemm l-ebda funzjoni prinċipali.

1229
00:57:32,820 --> 00:57:35,430
Inti biss tibda bil-miktub il-kodiċi
u se jiksbu eżegwit, jew

1230
00:57:35,430 --> 00:57:36,900
interpretat b'mod aktar xieraq.

1231
00:57:36,900 --> 00:57:38,660
Kondizzjonijiet se teżamina bħal dan.

1232
00:57:38,660 --> 00:57:41,230
Differenti minn C jew
PHP għal dik il-kwistjoni.

1233
00:57:41,230 --> 00:57:43,890
Espressjonijiet Boolean jew 'ed flimkien
se teżamina bħal dan.

1234
00:57:43,890 --> 00:57:45,590
Anded flimkien teżamina bħal dan.

1235
00:57:45,590 --> 00:57:47,750
>> Swiċċijiet se teżamina bħal dan.

1236
00:57:47,750 --> 00:57:49,440
Għal loops se teżamina bħal dan.

1237
00:57:49,440 --> 00:57:51,060
Filwaqt loops se teżamina bħal dan.

1238
00:57:51,060 --> 00:57:53,316
Tagħmel filwaqt loops se teżamina bħal dan.

1239
00:57:53,316 --> 00:57:54,780
>> Dan huwa ġdid.

1240
00:57:54,780 --> 00:57:58,753
Allura JavaScript ma jkollux foreach
tibni per se, iżda dan jinbena

1241
00:57:58,753 --> 00:58:03,870
għall i varjabbli array, ui f'dan
każ isir valur indiċi.

1242
00:58:03,870 --> 00:58:06,880
Allura huwa xi ftit differenti minn dik
foreach, għalkemm verżjonijiet ġodda ta '

1243
00:58:06,880 --> 00:58:10,280
JavaScript huma joħorġu l-ħin kollu,
hekk anke dawn lingwa karatteristiċi

1244
00:58:10,280 --> 00:58:10,880
qed jevolvu.

1245
00:58:10,880 --> 00:58:16,920
>> U Bħala twarrib, JavaScript dawn il-jiem
jista 'jintuża wkoll fuq server bħad

1246
00:58:16,920 --> 00:58:19,920
PHP billi jużaw qafas imsejjaħ Node.js.

1247
00:58:19,920 --> 00:58:24,670
Waħda mill-TFS CS50, il Kevin, wassal a
seminar fuq Node.js li ikunu disponibbli fuq

1248
00:58:24,670 --> 00:58:26,440
cs50.net/seminars.

1249
00:58:26,440 --> 00:58:28,830
Mela jekk int kurjuż, taf li inti
jistgħu jużaw dan fuq in-naħa server bħala

1250
00:58:28,830 --> 00:58:33,870
ukoll, iżda li l-xejra pjuttost reċenti,
iżda waħda qawwija f'dak.

1251
00:58:33,870 --> 00:58:35,270
>> Dan huwa xi ftit differenti.

1252
00:58:35,270 --> 00:58:37,910
Dan huwa firxa fl JavaScript.

1253
00:58:37,910 --> 00:58:40,115
U dak strajkijiet inti bħala differenti
versus C jew PHP?

1254
00:58:40,115 --> 00:58:43,890

1255
00:58:43,890 --> 00:58:47,420
Hemm stejjer malajr ftit
nistgħu tell hawn.

1256
00:58:47,420 --> 00:58:49,367
X'hemm nieqes versus PHP?

1257
00:58:49,367 --> 00:58:51,652
>> UDJENZA: [inaudible].

1258
00:58:51,652 --> 00:58:52,110
>> DAVID Malan: Iva?

1259
00:58:52,110 --> 00:58:53,322
Jiddispjacini, ngħid?

1260
00:58:53,322 --> 00:58:54,740
>> UDJENZA: Mhux tiddikjara
it-tip ta 'varjabbli.

1261
00:58:54,740 --> 00:58:56,390
>> DAVID Malan: Aħna ma tiddikjara
it-tip ta 'varjabbli.

1262
00:58:56,390 --> 00:58:59,630
Allura fil-fatt pjuttost simili PHP, aħna mhux qed
tispeċifika t-tipi ta 'dan il-varjabbli.

1263
00:58:59,630 --> 00:59:02,670
Pjuttost, aħna qed aktar ġeneriku
qal var għall varjabbli.

1264
00:59:02,670 --> 00:59:06,690
Aħna ma jkollhom inkonvenjent PHP tal-
sinjal dollaru, li filwaqt li tedious biex

1265
00:59:06,690 --> 00:59:09,160
tip, ma tagħmel aktar ċara li
xi ħaġa l-varjabbli.

1266
00:59:09,160 --> 00:59:11,830
Billi hawnhekk, aħna qed tip ta 'lura għall-
Approċċ C billi sempliċiment ssejjaħ

1267
00:59:11,830 --> 00:59:14,500
varjabbli bl-isem irridu
biex jagħtuh, bħal numri.

1268
00:59:14,500 --> 00:59:17,170
U wkoll bħal PHP, għandna
parentesi kwadri għall-

1269
00:59:17,170 --> 00:59:19,170
Valuri ġewwa li array.

1270
00:59:19,170 --> 00:59:22,490
>> Allura varjabbli fil JavaScript wkoll
tista 'tidher bħal dan.

1271
00:59:22,490 --> 00:59:26,900
Avviż hawn dan huwa string imsejħa s,
iżda bl-istess mod li aħna mhux speċifikat

1272
00:59:26,900 --> 00:59:28,750
li huwa string.

1273
00:59:28,750 --> 00:59:33,160
Hawnhekk għalkemm hija karatteristika li ma
jeżistu eżattament fl-istess mod fil-PHP,

1274
00:59:33,160 --> 00:59:34,460
iżda ftit simili.

1275
00:59:34,460 --> 00:59:36,530
Dan huwa oġġett fil JavaScript.

1276
00:59:36,530 --> 00:59:42,110
U l-oġġetti huma tip ta 'l-Armata Svizzera
Sikkina ta 'struttura data li inti

1277
00:59:42,110 --> 00:59:43,900
tista 'tużahom għal kull numru ta' affarijiet.

1278
00:59:43,900 --> 00:59:46,860
>> Hawnhekk, per eżempju, aħna qed tiddikjara
kwotazzjoni varjabbli imsejħa.

1279
00:59:46,860 --> 00:59:49,110
It-tip ta 'dak il-varjabbli
huwa oġġett.

1280
00:59:49,110 --> 00:59:53,550
Inti tista 'taħseb dan bħala Struct C
li għandha keys u l-valuri.

1281
00:59:53,550 --> 00:59:55,250
Simbolu huwa ċentrali.

1282
00:59:55,250 --> 00:59:57,350
FB hija valur, apparentement
simbolu istokk.

1283
00:59:57,350 --> 00:59:57,930
Virgola.

1284
00:59:57,930 --> 01:00:02,180
Prezz ieħor huwa importanti, u l-valur tagħha huwa
apparentement punt floating, jew

1285
01:00:02,180 --> 01:00:06,510
numru iktar ġenerali fir-
JavaScript, ta '$ 49.26.

1286
01:00:06,510 --> 01:00:09,030
>> Allura PHP ma jkollhom -

1287
01:00:09,030 --> 01:00:12,980
ma rajniex fil PHP oġġetti pjuttost
bħal dan, imma aħna ma tara Analog,

1288
01:00:12,980 --> 01:00:14,093
li kien dak?

1289
01:00:14,093 --> 01:00:14,980
>> UDJENZA: [inaudible].

1290
01:00:14,980 --> 01:00:16,110
>> DAVID Malan: arrays assoċjattiva.

1291
01:00:16,110 --> 01:00:19,990
Allura billi PHP arrays assoċjattiva
li sintassi hija qatt ftit hekk

1292
01:00:19,990 --> 01:00:20,370
differenti -

1293
01:00:20,370 --> 01:00:21,780
rajna il-parentesi kwadri.

1294
01:00:21,780 --> 01:00:23,860
Rajna l-simboli vleġeġ stramb.

1295
01:00:23,860 --> 01:00:27,330
JavaScript għandha oġġetti, iżda dan huwa
aktar differenza semantika u

1296
01:00:27,330 --> 01:00:29,260
sinonimu differenti għal issa.

1297
01:00:29,260 --> 01:00:35,060
Madankollu, bħala twarrib, PHP għandha wkoll
oġġetti b'mod li Java u oħrajn

1298
01:00:35,060 --> 01:00:37,810
lingwi jkollhom oġġetti fl
ipprogrammar oġġett orjentati lejn.

1299
01:00:37,810 --> 01:00:40,440
Iżda aħna ser tuża dawn biss
għal tipi ta 'data għal issa.

1300
01:00:40,440 --> 01:00:42,170
Oġġetti u matriċi assoċjattiva.

1301
01:00:42,170 --> 01:00:44,140
>> Dan wieħed jista 'jagħmilha
ftit aktar ċara.

1302
01:00:44,140 --> 01:00:45,890
Hawn għaliex l-oġġett huwa utli.

1303
01:00:45,890 --> 01:00:48,760
Meta inti tixtieq li tiddikjara student,
bħal Zamyla, nistgħu attwalment

1304
01:00:48,760 --> 01:00:52,630
jirrappreżentaw biex ngħidu hekk ġewwa ta 'dan
oġġett li jużaw parentesi kaboċċi bħad

1305
01:00:52,630 --> 01:00:55,060
qabel mazz sħiħ ta 'ċwievet
u valuri fil hawn.

1306
01:00:55,060 --> 01:00:59,150
Għandna ID, dar, u l-isem għall-
Zamyla, segwit b'waqfa u virgola bħala

1307
01:00:59,150 --> 01:01:00,690
soltu fl-aħħar.

1308
01:01:00,690 --> 01:01:04,840
>> Down hawnhekk ukoll, dan huwa kemmxejn
differenti, iżda wkoll qawwija ħafna

1309
01:01:04,840 --> 01:01:05,690
dawn il-jiem.

1310
01:01:05,690 --> 01:01:08,780
Hawn firxa, u naf li minħabba
hemm bracket up kwadru

1311
01:01:08,780 --> 01:01:11,090
top u bracket kwadru
fil-qiegħ.

1312
01:01:11,090 --> 01:01:16,050
U dan huwa firxa ta 'dak data
tip apparentament JavaScript?

1313
01:01:16,050 --> 01:01:21,260
Dan huwa firxa ta 'jidher
bħal tliet oġġetti.

1314
01:01:21,260 --> 01:01:24,580
U naf huwa oġġett biss
minħabba l-ċingi kaboċċi.

1315
01:01:24,580 --> 01:01:28,760
U avviż hemm Brace kaboċċi miftuħa,
xi għalf, Brace kaboċċi qrib, comma,

1316
01:01:28,760 --> 01:01:31,180
mbagħad ftit aktar, comma,
u mbagħad ftit aktar.

1317
01:01:31,180 --> 01:01:33,800
Allura dak tliet argumenti
separati minn żewġ virgoli.

1318
01:01:33,800 --> 01:01:36,810
>> Allura dan huwa firxa ta 'tliet oġġetti.

1319
01:01:36,810 --> 01:01:39,940
U kull wieħed minn dawk l-oġġetti tidher li
membru student jew persunal ta 'xi

1320
01:01:39,940 --> 01:01:42,370
sort, kull ma 'ID,
house, u l-isem.

1321
01:01:42,370 --> 01:01:45,060
Imma stajt sejjaħ din xi ħaġa
imsejħa JSON -

1322
01:01:45,060 --> 01:01:47,450
JavaScript Għan Notazzjoni.

1323
01:01:47,450 --> 01:01:52,060
U dan huwa format data li attwalment
huwa tant popolari ħafna u

1324
01:01:52,060 --> 01:01:55,100
Vogue dawn il-jiem li jekk inti tikteb
applikazzjoni li juża l-Facebook

1325
01:01:55,100 --> 01:01:59,150
API, l-API Twitter, verament kważi
kwalunkwe API hemmhekk f'dawn il-jiem,

1326
01:01:59,150 --> 01:02:02,820
inklużi xi wħud CS50 stess, il-
data ikollok lura ma jkunx

1327
01:02:02,820 --> 01:02:04,720
qodma format CSV iskola.

1328
01:02:04,720 --> 01:02:06,780
>> Minħabba jfakkru li CSV
huwa sempliċi super.

1329
01:02:06,780 --> 01:02:10,230
Huwa biss kolonni separati
b'virgoli.

1330
01:02:10,230 --> 01:02:13,190
JSON data jagħtik aktar metadata.

1331
01:02:13,190 --> 01:02:17,800
Hija assoċjati buttuna ma 'kull valur hekk
dawn ma jkollhom biss wieħed jassumi li

1332
01:02:17,800 --> 01:02:22,460
il-kolonna 0 hija valur wieħed, kolonna
waħda hija ieħor, kolonna tnejn huwa ieħor.

1333
01:02:22,460 --> 01:02:26,790
Kollox fil oġġett JSON hawnhekk huwa tip
ta 'awto-deskrizzjoni, għaliex kull

1334
01:02:26,790 --> 01:02:30,940
wieħed mill-ismijiet fil dan il-fajl għandu litteralment
isem fil-quddiem ta 'dan bħala

1335
01:02:30,940 --> 01:02:32,510
string ikkwotat.

1336
01:02:32,510 --> 01:02:34,950
>> Mela ejja tagħti ħarsa lejn
ftit eżempji hawn.

1337
01:02:34,950 --> 01:02:36,800
Let me jmorru fil-appliance.

1338
01:02:36,800 --> 01:02:41,000
U let me go fis vhost tagħna
direttorju fis pubbliku.

1339
01:02:41,000 --> 01:02:45,590
U let me jmorru fil-
JavaScript direttorju.

1340
01:02:45,590 --> 01:02:49,610
U ejja imorru quddiem u tiftaħ
dom-0.html, fejn DOM ifisser biss

1341
01:02:49,610 --> 01:02:51,010
mudell tad-dokument oġġett.

1342
01:02:51,010 --> 01:02:53,490
Hu l-għalf siġra li
I imsemmi qabel.

1343
01:02:53,490 --> 01:02:54,950
>> U let me nipproponi dan li ġej.

1344
01:02:54,950 --> 01:02:57,720
Hawn paġna web li
korp huwa pjuttost sempliċi.

1345
01:02:57,720 --> 01:03:00,170
Allura stabbiliti hawn fil-qiegħ,
Avviż I jkollhom forma.

1346
01:03:00,170 --> 01:03:01,500
Rajna dawk ta 'qabel.

1347
01:03:01,500 --> 01:03:07,600
Din għandha żewġ inputs, li waħda minnhom għandha
ID tal-isem, li waħda minnhom għandha tip ta '

1348
01:03:07,600 --> 01:03:09,830
jissottomettu, u l-ewwel
tip wieħed huwa test.

1349
01:03:09,830 --> 01:03:11,900
Allura dan fil-fatt ħsejjes pretty sempliċi.

1350
01:03:11,900 --> 01:03:13,090
>> Ejja mur hawn.

1351
01:03:13,090 --> 01:03:15,390
Ejja ħa mmorru lura għall din il-paġna hawn.

1352
01:03:15,390 --> 01:03:21,030
Ejja jmorru fil localhost, u jmorru fil
direttorju JavaScript tagħna, u mur

1353
01:03:21,030 --> 01:03:24,640
dom-0, u hawnhekk għandna din il-formola.

1354
01:03:24,640 --> 01:03:26,550
Allura dak apparentement
kollha din il-paġna ma.

1355
01:03:26,550 --> 01:03:28,740
Hija għandha kamp isem ma
a Issottometti buttuna.

1356
01:03:28,740 --> 01:03:30,340
Imma jien mhux ser tuża PHP hawn.

1357
01:03:30,340 --> 01:03:34,310
Jien ser tagħmel naħa tal-klijent kollox
biex ngħidu hekk fil JavaScript kif ġej.

1358
01:03:34,310 --> 01:03:39,100
>> Avviż li stajt tabilħaqq jingħata l-isem
qasam ta 'dan il-kontribut uniku

1359
01:03:39,100 --> 01:03:42,350
identifier, li fil-fatt se
ħlief lili xi żmien fil-mument.

1360
01:03:42,350 --> 01:03:45,480
U avviż stajt introdotti tag ieħor
fir-ras tal-paġna web tiegħi, l-

1361
01:03:45,480 --> 01:03:46,565
 tag.

1362
01:03:46,565 --> 01:03:50,120
>> Allura huwa f'dan is-sens li JavaScript huwa
lingwa ta 'programmar client-side.

1363
01:03:50,120 --> 01:03:55,020
F'dan il-każ, bħal CSS, stajt jitqiegħdu
hija dritta ġewwa ta HTML tiegħi.

1364
01:03:55,020 --> 01:03:58,810
Imma avviż stajt ddikjarat funzjoni
li jistenna ftit bħal PHP

1365
01:03:58,810 --> 01:04:01,530
sintattiku, iżda dan huwa attwalment
JavaScript, għaliex għal darb'oħra, huwa

1366
01:04:01,530 --> 01:04:03,920
client-side fil-browser.

1367
01:04:03,920 --> 01:04:07,590
U tieħu raden dak li din se
tagħmel, anki jekk uħud mill-sintassi

1368
01:04:07,590 --> 01:04:09,338
hawnhekk huwa ġdid.

1369
01:04:09,338 --> 01:04:11,760
>> UDJENZA: Say bonjour min.

1370
01:04:11,760 --> 01:04:14,020
>> DAVID Malan: Huwa ser jgħidu bonjour
lil min żjarat din il-paġna.

1371
01:04:14,020 --> 01:04:15,120
Iva, kif?

1372
01:04:15,120 --> 01:04:18,070
>> Għalhekk avviż, jirriżulta fl JavaScript
hemm twissija () funzjoni.

1373
01:04:18,070 --> 01:04:22,840
Dan huwa tip ħafna ta 'funzjoni diqa li
verament ftit tendenza li idejqu utenti.

1374
01:04:22,840 --> 01:04:25,440
Mhuwiex waħda għandek verament użu
tipikament, imma hija malajr u maħmuġin

1375
01:04:25,440 --> 01:04:27,710
mod ta 'tip ta' stampar xi ħaġa
lil utent grafika

1376
01:04:27,710 --> 01:04:29,180
interface, bħal browser.

1377
01:04:29,180 --> 01:04:31,400
Avviż hawnhekk li stajt ltqajna
string fil kwotazzjonijiet uniku.

1378
01:04:31,400 --> 01:04:36,010
Jirriżulta li b'differenza C, JavaScript
jista 'effettivament tuża wieħed

1379
01:04:36,010 --> 01:04:38,730
kwotazzjonijiet, u franchement huwa biss tip
tal-konvenzjoni stilistiċi fost

1380
01:04:38,730 --> 01:04:41,180
Programmaturi JavaScript
għall-użu kwotazzjonijiet uniku.

1381
01:04:41,180 --> 01:04:43,750
PHP, dawn għandhom attwalment ftit
tifsira differenti.

1382
01:04:43,750 --> 01:04:45,810
Iżda għal issa, biss jafu li
dak l-uniku raġuni.

1383
01:04:45,810 --> 01:04:49,270
Il-konvenzjoni fl JavaScript huwa spiss biex
jużaw kwotazzjonijiet uniku, imma aħna jistgħu jużaw

1384
01:04:49,270 --> 01:04:50,950
kwotazzjonijiet doppja fiż-żewġ postijiet ukoll.

1385
01:04:50,950 --> 01:04:52,610
>> Allura dan huwa interessanti.

1386
01:04:52,610 --> 01:04:56,430
Ifakkar aħħar darba li kellna li
istampa fuq l-iskrin li ġibdet siġra

1387
01:04:56,430 --> 01:04:59,720
fejn kellek l-HTML node, u l-
node ras, u l-node ġisem,

1388
01:04:59,720 --> 01:05:00,800
u mbagħad xi test.

1389
01:05:00,800 --> 01:05:04,700
Imma kien hemm node wieħed speċjali fil-
top ħafna li I imsejħa id-dokument.

1390
01:05:04,700 --> 01:05:08,260
Ukoll, jirriżulta b'mod JavaScript, kull
ħin tikteb programm JavaScript

1391
01:05:08,260 --> 01:05:11,040
fil-browser, ikollok aċċess għal
varjabbli globali speċjali.

1392
01:05:11,040 --> 01:05:14,130
Simili fl-ispirtu li superglobals PHP,
dan wieħed huwa msejjaħ fl

1393
01:05:14,130 --> 01:05:16,050
kollha dokument zghar.

1394
01:05:16,050 --> 01:05:21,480
>> Huwa simili Struct, iżda dan Struct
għandha wkoll funzjonijiet ġewwa ta 'dan.

1395
01:05:21,480 --> 01:05:23,790
Allura Struct C biss għandu data tipikament.

1396
01:05:23,790 --> 01:05:29,060
Iżda oġġett JavaScript kif dan
teknikament huwa wkoll il-funzjonijiet,

1397
01:05:29,060 --> 01:05:31,830
inkella magħruf bħala metodi,
ġewwa ta 'dan.

1398
01:05:31,830 --> 01:05:35,750
U inti tista 'sejħa funzjoni ġewwa ta'
dan l-oġġett pjuttost litteralment tagħmel tagħha

1399
01:05:35,750 --> 01:05:39,610
isem, dot, u allura l-isem ta '
il-funzjoni, jew għal darb'oħra metodu.

1400
01:05:39,610 --> 01:05:41,160
Huwa biss sinonimu, verament.

1401
01:05:41,160 --> 01:05:42,450
>> U dak ma din il-funzjoni do?

1402
01:05:42,450 --> 01:05:43,840
Tista 'tip ta' raden mill-isem tagħha.

1403
01:05:43,840 --> 01:05:45,590
Get element mill ID.

1404
01:05:45,590 --> 01:05:50,040
Allura dan se tfittex il-paġna web,
tfittxija li siġra, tfittex

1405
01:05:50,040 --> 01:05:55,210
kwalunkwe node, element AKA, għandha
ID unika ta 'isem unquote kwotazzjoni.

1406
01:05:55,210 --> 01:05:56,560
U allura dak li jien se jagħmlu?

1407
01:05:56,560 --> 01:06:00,350
Jien ser tikseb l-valur ġewwa ta '
li node fil-siġra, u jien ser

1408
01:06:00,350 --> 01:06:02,580
li b'xi mod jgħidu bonjour dak l-isem.

1409
01:06:02,580 --> 01:06:05,360
>> Allura tieħu raden, anke jekk aħna ħadthom ma
rajt dan għadu, liema jagħmlu l-plus

1410
01:06:05,360 --> 01:06:07,396
simboli jfissirx hawn u hawn probabbilment?

1411
01:06:07,396 --> 01:06:08,230
>> UDJENZA: concatenate.

1412
01:06:08,230 --> 01:06:09,220
>> DAVID Malan: concatenate.

1413
01:06:09,220 --> 01:06:11,290
Dritt, u dawn huma biss
tip ta 'disinn deċiżjonijiet

1414
01:06:11,290 --> 01:06:12,280
nies għamlu snin ilu.

1415
01:06:12,280 --> 01:06:15,190
Fil PHP, inti concatenate
affarijiet ma tikek.

1416
01:06:15,190 --> 01:06:18,800
Fl C, inti jaqbżu permezz ta 'diversi ċrieki u
sejħa funzjonijiet simili strcopy () jew

1417
01:06:18,800 --> 01:06:20,600
strcat () jew funzjonijiet oħra bħal dawn.

1418
01:06:20,600 --> 01:06:22,060
Iżda fl JavaScript, tuża pluses.

1419
01:06:22,060 --> 01:06:24,770
Allura dan huwa biss concatenating
tliet kordi -

1420
01:06:24,770 --> 01:06:27,850
hello, isem, u mbagħad
punt exclamation.

1421
01:06:27,850 --> 01:06:30,390
>> Allura meta u għaliex din il-funzjoni
imsejħa għalkemm?

1422
01:06:30,390 --> 01:06:33,150
Well, tieħu raden mill-
HTML fil-qiegħ.

1423
01:06:33,150 --> 01:06:35,810
Għaliex huwa insellem () imsejħa, jew meta?

1424
01:06:35,810 --> 01:06:39,730

1425
01:06:39,730 --> 01:06:44,030
>> Apparentement, bħala l-aħjar I tista 'tgħid, fuq
iressaq, meta tiġi ppreżentata din il-formola,

1426
01:06:44,030 --> 01:06:47,200
Jien ser nagħmel kull ma huwa
ġewwa ta 'dawn il-kwotazzjonijiet.

1427
01:06:47,200 --> 01:06:50,900
U speċifikament, jien ser sejħa
insellem () u mbagħad jirritornaw falza.

1428
01:06:50,900 --> 01:06:53,090
>> Well, ejja ara dak ix-xibka
effett hawnhekk huwa l-ewwel.

1429
01:06:53,090 --> 01:06:58,290
So let me jimxi 'l quddiem u t-tip
fi, ngħidu aħna, Loren, Submit.

1430
01:06:58,290 --> 01:06:59,440
Hello Loren.

1431
01:06:59,440 --> 01:07:02,990
Ejja ara jekk forsi dan kien biss
implimentazzjoni xxurtjati.

1432
01:07:02,990 --> 01:07:03,200
Nope.

1433
01:07:03,200 --> 01:07:05,990
Allura huwa ittajpjar kwalunkwe
isem I attwalment stabbiliti hemmhekk.

1434
01:07:05,990 --> 01:07:07,970
>> Imma avviż dak li ma nbidilx.

1435
01:07:07,970 --> 01:07:10,360
Il-URL għadu dom-0.html.

1436
01:07:10,360 --> 01:07:11,820
M'hemm l-ebda register.php.

1437
01:07:11,820 --> 01:07:13,110
M'hemm l-ebda tieni fajl.

1438
01:07:13,110 --> 01:07:14,930
M'hemm l-ebda attribut azzjoni.

1439
01:07:14,930 --> 01:07:19,720
Allura x'inhi din falz ritorn
preżumibbilment tagħmel?

1440
01:07:19,720 --> 01:07:23,660
Why am I ssejjaħ insellem () u mbagħad
jirritornaw falza probabbilment?

1441
01:07:23,660 --> 01:07:26,420
Liema normalment jiġri meta tikklikkja
Issottometti fuq formola li anke għandna

1442
01:07:26,420 --> 01:07:27,854
raw fil-passat ġimgħa?

1443
01:07:27,854 --> 01:07:29,900
>> UDJENZA: [inaudible].

1444
01:07:29,900 --> 01:07:30,860
>> DAVID Malan: Hija tmur x'imkien, right?

1445
01:07:30,860 --> 01:07:32,720
Hija tmur għal xi URL destinazzjoni.

1446
01:07:32,720 --> 01:07:34,120
Imma ma rridx li jiġri hawn.

1447
01:07:34,120 --> 01:07:37,620
Irrid paġna web tiegħi li tkun kompletament
dinamika bħal Gmail, fejn darba int

1448
01:07:37,620 --> 01:07:38,650
hemm, inti toqgħod hemm.

1449
01:07:38,650 --> 01:07:42,900
Il-URL ma jinbidilx b'mod li
jindika l-paġna kollha hija tagħbija mill-ġdid.

1450
01:07:42,900 --> 01:07:46,680
Pjuttost, I biss trid tibdel xi ħaġa
bħal stampar ħaġa

1451
01:07:46,680 --> 01:07:48,320
hawn fuq l-iskrin.

1452
01:07:48,320 --> 01:07:49,630
>> Well let me jitnaddfu dan
up ftit.

1453
01:07:49,630 --> 01:07:55,370
Let me jiftħu mhux dom-0, iżda
let me jiftħu dom-2.

1454
01:07:55,370 --> 01:07:57,350
Just sabiex inti stajt tidher xi sintassi hawn.

1455
01:07:57,350 --> 01:08:02,080
>> Jirriżulta li dak li aħna biss
ma qed tuża JavaScript prima.

1456
01:08:02,080 --> 01:08:04,420
Allura dan huwa verament il-lingwa
JavaScript.

1457
01:08:04,420 --> 01:08:07,340
Xi wħud inti tista 'taf
librerija imsejjaħ jQuery.

1458
01:08:07,340 --> 01:08:09,980
>> Allura jQuery mhijiex l-istess
Ħaġa bħala JavaScript.

1459
01:08:09,980 --> 01:08:14,110
Huwa biss librerija li verament smart
Guy kiteb u popularized bħal

1460
01:08:14,110 --> 01:08:18,100
li kważi kulħadd fid-dinja issa
użi jQuery meta jużaw JavaScript.

1461
01:08:18,100 --> 01:08:20,890
U fl-ewwel daqqa t'għajn, onestament, huwa
jistenna ftit aktar cryptic.

1462
01:08:20,890 --> 01:08:24,990
Imma inti ser issib, speċjalment jekk inti tmur
hemm għall-proġett finali tiegħek ma 'web

1463
01:08:24,990 --> 01:08:29,029
żvilupp, inti ser issib li dan
cleans affarijiet up u jiffranka pjuttost

1464
01:08:29,029 --> 01:08:30,229
ftit linji tal-kodiċi.

1465
01:08:30,229 --> 01:08:33,189
>> Mela ejja biss t'għajn lejn kif
din il-forma qed taħdem.

1466
01:08:33,189 --> 01:08:35,664
Avviż dak li għamlet I neħħi apparentement
minn HTML tiegħi?

1467
01:08:35,664 --> 01:08:38,240

1468
01:08:38,240 --> 01:08:40,630
M'hemm l-ebda fuq jissottometti handler
biex ngħidu hekk.

1469
01:08:40,630 --> 01:08:41,470
M'hemm l-ebda attribut.

1470
01:08:41,470 --> 01:08:43,359
Għaliex inti taf, liema
I ma verament simili?

1471
01:08:43,359 --> 01:08:45,640
Ħassejtni qisni konna jaqgħu
fis drawwiet qodma hemmhekk.

1472
01:08:45,640 --> 01:08:49,340
Biss bhalu kienet tibda jħossu sloppy
intermingle kemm CSS ma

1473
01:08:49,340 --> 01:08:52,149
HTML, għax int tip ta 'jitfg
lingwi differenti kollha fuq il-

1474
01:08:52,149 --> 01:08:56,180
post, bl-istess mod ma din tibda tħossok
bħal triq ħażina li jonqsu fejn

1475
01:08:56,180 --> 01:09:01,069
Jien tqegħid kodiċi JavaScript ġewwa tal tiegħi
HTML minflok factoring out.

1476
01:09:01,069 --> 01:09:02,279
>> Allura dak hu l-lezzjoni hawn.

1477
01:09:02,279 --> 01:09:05,080
Fil dom-2.html, jien factoring out.

1478
01:09:05,080 --> 01:09:07,399
U jien tagħmel affarijiet ftit
differenti.

1479
01:09:07,399 --> 01:09:09,630
Għal issa, jien ser mewġa idejn tiegħi
lejn dak li dan verament ma

1480
01:09:09,630 --> 01:09:10,590
taħt il-barnuża.

1481
01:09:10,590 --> 01:09:14,210
Iżda biss għal issa jassumi li l-ewwel
linja tal-kodiċi fil din il-librerija

1482
01:09:14,210 --> 01:09:18,170
imsejħa jQuery ifisser biss meta l-
dokument huwa lest, jagħmel dan li ġej.

1483
01:09:18,170 --> 01:09:20,080
>> Minħabba paġni tal-web tista 'tieħu
xi żmien biex tagħbija.

1484
01:09:20,080 --> 01:09:23,029
Inti tista 'tkun fuq l-internet bil-mod
konnessjoni, u jista 'jiġi għażil

1485
01:09:23,029 --> 01:09:25,290
u għażil, u finalment huwa mgħobbija.

1486
01:09:25,290 --> 01:09:29,060
Dan l-kodiċi biss jgħid stenna sakemm
il-paġna kollha hija lesta, id-dokument

1487
01:09:29,060 --> 01:09:31,189
hija lesta, qabel ma teżegwixxi dan il-kodiċi.

1488
01:09:31,189 --> 01:09:34,390
>> U issa avviż, dan huwa probabbilment
l-aktar utli ewwel

1489
01:09:34,390 --> 01:09:36,189
jieħdu l bogħod mill jQuery.

1490
01:09:36,189 --> 01:09:42,140
Din il-linja hawnhekk huwa simili ħafna fl-ispirtu
għal din il-linja ħafna itwal hawn.

1491
01:09:42,140 --> 01:09:46,920
Billi fil-kodiċi JavaScript prima, hemm
jeżisti dokument oġġett globali li

1492
01:09:46,920 --> 01:09:50,460
għandha funzjoni msejħa getElementById (),
l-persuni li kiteb

1493
01:09:50,460 --> 01:09:55,720
jQuery simplifikata li biss jgħidu
sinjal dollaru, u mbagħad ġewwa ta '

1494
01:09:55,720 --> 01:10:00,250
parentesi tpoġġi żewġ kwotazzjonijiet, u mbagħad
tpoġġi simbolu hash segwita mill-

1495
01:10:00,250 --> 01:10:02,250
ID unika inti tixtieq li grab.

1496
01:10:02,250 --> 01:10:06,170
Allura dan huwa ekwivalenti għal
document.getElementById.

1497
01:10:06,170 --> 01:10:11,090
>> Sadanittant,. Tissottometti ifisser biss fuq
sottomissjoni ta 'kwalunkwe forma int

1498
01:10:11,090 --> 01:10:14,240
jirreferu għall fuq ix-xellug, mur
quddiem u tesegwixxi dan.

1499
01:10:14,240 --> 01:10:16,600
Imma issa dan huwa l-kurżità wisq.

1500
01:10:16,600 --> 01:10:19,560
X'hemm stramb dwar dak
Stajt enfasizzat hawn?

1501
01:10:19,560 --> 01:10:23,840

1502
01:10:23,840 --> 01:10:28,594
Mhux biss huwa tip ta 'sintattiku
ġdid, hemm ukoll xi ħaġa nieqsa.

1503
01:10:28,594 --> 01:10:29,558
>> UDJENZA: Huwa biss imsejħa funzjoni?

1504
01:10:29,558 --> 01:10:31,970
Mhuwiex sejjaħ allert?

1505
01:10:31,970 --> 01:10:32,440
>> DAVID Malan: Yeah.

1506
01:10:32,440 --> 01:10:35,450
Ukoll, sabiex twissija () huwa jistabbilixxi
hawn, li tkun ġusta.

1507
01:10:35,450 --> 01:10:39,520
Imma m'hemm l-ebda referenza ta '
isem, bħal inti taf, foo jew

1508
01:10:39,520 --> 01:10:40,980
xi ħaġa up here.

1509
01:10:40,980 --> 01:10:43,830
U fil-fatt, din hija waħda mill-karatteristiċi
ta 'JavaScript li pjuttost

1510
01:10:43,830 --> 01:10:45,370
qawwija, iżda wkoll pjuttost ġdida.

1511
01:10:45,370 --> 01:10:47,460
U PHP attwalment għandha dan ukoll.

1512
01:10:47,460 --> 01:10:49,500
>> Let me imorru quddiem u tagħmel
ħaġa reali malajr.

1513
01:10:49,500 --> 01:10:52,030
Let me imorru quddiem u jdaħħlu dan hawn.

1514
01:10:52,030 --> 01:10:52,600
Let me jagħmlu dan.

1515
01:10:52,600 --> 01:10:53,690
Funzjoni.

1516
01:10:53,690 --> 01:10:56,455
Ejja sejħa dan handler ().

1517
01:10:56,455 --> 01:10:58,290
A funzjoni handler biex ngħidu hekk.

1518
01:10:58,290 --> 01:11:00,110
Xi ħaġa li mankijiet xi operazzjoni.

1519
01:11:00,110 --> 01:11:02,700
Let me tnaddaf indentazzjoni tiegħi.

1520
01:11:02,700 --> 01:11:04,380
U jdaħħlu dan hawn.

1521
01:11:04,380 --> 01:11:06,090
U mqiegħda dak hawn.

1522
01:11:06,090 --> 01:11:06,470
Yep.

1523
01:11:06,470 --> 01:11:07,060
OK.

1524
01:11:07,060 --> 01:11:10,300
>> Allura issa I jkollhom funzjoni msejħa
handler () li jien ma verament jafu

1525
01:11:10,300 --> 01:11:10,890
x'tagħmel s'issa.

1526
01:11:10,890 --> 01:11:12,710
Hija biss għad għandha li Jittieħed.

1527
01:11:12,710 --> 01:11:13,900
Whoops.

1528
01:11:13,900 --> 01:11:15,820
Ħa wisq.

1529
01:11:15,820 --> 01:11:18,490
Ejja nagħmlu dan.

1530
01:11:18,490 --> 01:11:18,990
Kull dritt.

1531
01:11:18,990 --> 01:11:20,240
Jiddispjacini.

1532
01:11:20,240 --> 01:11:23,140

1533
01:11:23,140 --> 01:11:23,690
Kull dritt.

1534
01:11:23,690 --> 01:11:24,720
Let me jagħmlu dan.

1535
01:11:24,720 --> 01:11:25,020
OK.

1536
01:11:25,020 --> 01:11:27,040
Li jistenna sbieħ u straight
jgħaddi issa.

1537
01:11:27,040 --> 01:11:29,090
Let me jagħmlu dan.

1538
01:11:29,090 --> 01:11:29,860
Jagħmlu dan.

1539
01:11:29,860 --> 01:11:30,950
U OK.

1540
01:11:30,950 --> 01:11:33,080
Allura issa, ejja tpoġġi dan hawn fuq.

1541
01:11:33,080 --> 01:11:35,840

1542
01:11:35,840 --> 01:11:37,270
Nru aktar ipprogrammar fuq il-fly.

1543
01:11:37,270 --> 01:11:37,900
OK.

1544
01:11:37,900 --> 01:11:40,000
>> Allura issa, ejja mur lura għall-
fejn l-istorja bdiet.

1545
01:11:40,000 --> 01:11:43,530
Preċedentement, I qal li din il-linja hawn
ifisser li meta d-dokument huwa lest, mur

1546
01:11:43,530 --> 01:11:44,380
quddiem u tagħmel dan.

1547
01:11:44,380 --> 01:11:45,660
What do I trid tagħmel?

1548
01:11:45,660 --> 01:11:49,070
Well speċifikament, Irrid immur
quddiem u tagħmel dan li ġej.

1549
01:11:49,070 --> 01:11:53,700
Jesegwixxi din il-linja tal-kodiċi, u mbagħad
dak li nixtieq li inti tagħmel huwa sejħa dan

1550
01:11:53,700 --> 01:11:56,370
tiffunzjonax meta tiġi ppreżentata l-formola.

1551
01:11:56,370 --> 01:11:57,730
>> Issa dan huwa dak interessanti.

1552
01:11:57,730 --> 01:11:59,170
Din mhix fiha nnifisha funzjoni.

1553
01:11:59,170 --> 01:12:02,540
Avviż I am not tqegħid parentesi
hawn fil-mod normali.

1554
01:12:02,540 --> 01:12:06,800
Jien litteralment jgħaddi funzjoni msejħa
handler () funzjoni oħra

1555
01:12:06,800 --> 01:12:10,800
imsejħa jissottomettu () bħala argument bħala
għalkemm huwa simili varjabbli.

1556
01:12:10,800 --> 01:12:14,290
U dan huwa wieħed mill-karatteristiċi ta '
JavaScript, hija funzjonijiet infushom

1557
01:12:14,290 --> 01:12:15,710
huma verament ftit oġġetti.

1558
01:12:15,710 --> 01:12:18,350
Fil-fatt, dawn qed verament ftit
varjabbli ta 'xi tip.

1559
01:12:18,350 --> 01:12:21,340
U jekk l-isem tal-funzjoni hija
handler (), m'hemm l-ebda raġuni ma nistax

1560
01:12:21,340 --> 01:12:23,390
jgħaddi bi bħala argument hawn.

1561
01:12:23,390 --> 01:12:27,530
U dan ifisser li meta l-formola
bl-ID tal demo huwa

1562
01:12:27,530 --> 01:12:29,320
sottomessa, sejħa din il-funzjoni.

1563
01:12:29,320 --> 01:12:32,770
>> Imma issa jekk I jneħħu kollha ta 'dan,
għaliex imbagħad ma I forsi do

1564
01:12:32,770 --> 01:12:34,850
dan mument ilu?

1565
01:12:34,850 --> 01:12:36,840
Ukoll, din hija funzjoni anonimu.

1566
01:12:36,840 --> 01:12:41,080
Minħabba franchement, I realizzati għaliex jien
bothering iskart ħin tiddikjara

1567
01:12:41,080 --> 01:12:45,540
funzjoni msejħa handler () biss sabiex jikkonfutaw
fil-wieħed u biss f'post wieħed?

1568
01:12:45,540 --> 01:12:48,640
Jekk I m'għandhomx bżonn l-isem, u jien ma
jeħtieġ li hija sejħa f'aktar minn post wieħed,

1569
01:12:48,640 --> 01:12:51,200
ejja biss jimplimenta l-funzjoni
dritt fejn I bżonnha.

1570
01:12:51,200 --> 01:12:55,190
U hekk JavaScript u PHP appoġġ liema
huma msejħa funzjonijiet anonimi li

1571
01:12:55,190 --> 01:12:57,900
ippermettuli biex tagħmel eżattament dan hawnhekk.

1572
01:12:57,900 --> 01:12:59,570
>> Iżda aħna qed biss grif tal-wiċċ.

1573
01:12:59,570 --> 01:13:02,430
Ejja tease biss bi ftit
eżempji finali hawn.

1574
01:13:02,430 --> 01:13:04,600
>> Jekk immur fis quote.php.

1575
01:13:04,600 --> 01:13:07,160

1576
01:13:07,160 --> 01:13:11,870
Avviż li dan huwa attwalment PHP
funzjoni, programm PHP, li I kiteb

1577
01:13:11,870 --> 01:13:15,270
li jistenna parametru HTTP imsejħa
simbolu, u I jistgħu jgħaddu fil-

1578
01:13:15,270 --> 01:13:16,730
valur bħal FB.

1579
01:13:16,730 --> 01:13:20,010
U jekk aħna verament tħares lejn is-sors
kodiċi, dan huwa juri dubji free website

1580
01:13:20,010 --> 01:13:23,680
imsejħa Yahoo Finanzi, bħal p-set
seba ', u huwa jirritorna għall me

1581
01:13:23,680 --> 01:13:26,580
xi ħaġa fil apparentement l-
format magħruf huwa JSON -

1582
01:13:26,580 --> 01:13:28,010
JavaScript Notazzjoni Għan.

1583
01:13:28,010 --> 01:13:28,810
Huwa biss oġġett.

1584
01:13:28,810 --> 01:13:32,500
Avviż tal-braces kaboċċi, l-kwotazzjonijiet,
-kolon, u l-virgoli.

1585
01:13:32,500 --> 01:13:34,720
>> Issa sadanittant, dan huwa pretty jibred.

1586
01:13:34,720 --> 01:13:38,520
Minħabba I tista 'probabbilment tuża programmar
lingwa li jiġġeneraw URLs

1587
01:13:38,520 --> 01:13:40,370
li look like dan dinamiku,
dritt?

1588
01:13:40,370 --> 01:13:43,340
I jistgħu jbiddlu dan Google
u terġa 'lura Google

1589
01:13:43,340 --> 01:13:47,930
prezz tat-titoli ta '$ 1,017.55.

1590
01:13:47,930 --> 01:13:49,640
Mela ejja ara jekk aħna ma tistax tuża dan issa.

1591
01:13:49,640 --> 01:13:56,590
>> Let me go għal ajax-0 hawn, li
qisu li ġej.

1592
01:13:56,590 --> 01:13:59,750
Huwa biss website li tkun
forma ma 'buttuna.

1593
01:13:59,750 --> 01:14:05,860
Let me here jimxi 'l quddiem u tip YHOO
għall-istokk simbolu Yahoo, ikklikkja Get

1594
01:14:05,860 --> 01:14:10,530
Quote, u issa avviż stajt gotten
twissija ma 32.86.

1595
01:14:10,530 --> 01:14:14,050
>> Let me fatt imorru għal verżjoni fancier
ta 'din il-paġna, verżjoni tnejn, u

1596
01:14:14,050 --> 01:14:17,530
tip fil ejja ngħidu Microsoft, MSFT.

1597
01:14:17,530 --> 01:14:18,410
Get Quote.

1598
01:14:18,410 --> 01:14:19,850
U issa avviż, l-ebda twissija.

1599
01:14:19,850 --> 01:14:22,770
Avviż fejn jgħid prezz
li għandu jiġi stabbilit?

1600
01:14:22,770 --> 01:14:27,060
Hemm l-aktar sempliċi ta 'eżempji li
ħjiel fuq dak Gchat, u Facebook

1601
01:14:27,060 --> 01:14:30,070
Chat, u Gmail, u oħrajn bħal
websites qed jagħmlu mill-fatt

1602
01:14:30,070 --> 01:14:31,290
jinbidlu l-web page.

1603
01:14:31,290 --> 01:14:31,800
>> Avviż dan.

1604
01:14:31,800 --> 01:14:33,120
Let me rikarigu-paġna.

1605
01:14:33,120 --> 01:14:35,080
Let me tiftaħ Ispettur Chrome.

1606
01:14:35,080 --> 01:14:36,890
Let me mur l-elementi
tab stabbiliti hawn.

1607
01:14:36,890 --> 01:14:42,310
Issa avviż jekk I zoom isfel hawn u
jinfetaħ dan up, avviż li dan huwa tiegħi

1608
01:14:42,310 --> 01:14:44,500
HTML DOM - dokument mudell oġġett tiegħi.

1609
01:14:44,500 --> 01:14:45,920
Dan huwa HTML tiegħi.

1610
01:14:45,920 --> 01:14:48,750
Imma issa avviż, anki jekk li għaddej
li jkun ftit diffiċli biex tara kemm

1611
01:14:48,750 --> 01:14:52,080
postijiet f'daqqa, jekk I tip fil FB
up hawn, tara l-qiegħ

1612
01:14:52,080 --> 01:14:54,110
ta 'l-iskrin biss.

1613
01:14:54,110 --> 01:14:57,720
>> Huwa fil-fatt jinbidlu
HTML tiegħi fuq il-fly.

1614
01:14:57,720 --> 01:15:01,670
U huwa jagħmel dan sempliċement
billi tagħmel xi ħaġa bħal din.

1615
01:15:01,670 --> 01:15:06,800
Jekk I jiftħu ajax-2, avviż implimentazzjoni
xi ħaġa sexy bħala

1616
01:15:06,800 --> 01:15:09,560
li, għalkemm huwa pjuttost ikrah,
iżda bħala sofistikata hekk kif dak

1617
01:15:09,560 --> 01:15:11,910
funzjonalment, għandha xi
HTML fil-qiegħ.

1618
01:15:11,910 --> 01:15:13,810
Imma avviż I użati biex tag.

1619
01:15:13,810 --> 01:15:16,640
Imxejna ma użawx din qabel, iżda dan huwa
bħal, iżda ma seħħ

1620
01:15:16,640 --> 01:15:17,840
kollox fuq linja ġdida.

1621
01:15:17,840 --> 01:15:20,830
Hija biss jagħmel reġjun rettangolari
fuq l-istess linja essenzjalment.

1622
01:15:20,830 --> 01:15:22,870
>> Avviż li I tatu ID ta 'prezz.

1623
01:15:22,870 --> 01:15:26,800
U jirriżulta billi tuża l-istess
JavaScript librerija, I għandhom funzjoni

1624
01:15:26,800 --> 01:15:30,440
imsejħa kwotazzjoni () li sejjaħ kull meta
il-formola tiġi sottomessa.

1625
01:15:30,440 --> 01:15:31,800
U dak li qed nagħmel huwa dan.

1626
01:15:31,800 --> 01:15:35,730
Jien tiddikjara varjabbli JavaScript
imsejħa url, iffrankar l-valur

1627
01:15:35,730 --> 01:15:38,650
quote.php? simbolu =.

1628
01:15:38,650 --> 01:15:44,220
Fi kliem ieħor, I myself am bidu
jħejju talba HTTP, u mbagħad

1629
01:15:44,220 --> 01:15:49,250
Jien concatenating fuq li bil-plus
ikun x'ikun l-element bl-ID

1630
01:15:49,250 --> 01:15:54,190
ta 'simbolu huwa, li l-avviż huwa li
qasam tat-test dritt isfel hawn.

1631
01:15:54,190 --> 01:15:56,630
Allura bħad kellna forom fil-passat.

1632
01:15:56,630 --> 01:16:01,450
>> U mbagħad jirriżulta fil jQuery, jekk inti
sejħa. val (), li s-sejħiet ta 'val

1633
01:16:01,450 --> 01:16:05,900
funzjoni, funzjoni valur, li gets
x'ikun l-utent ikun ittajpjat pulzieri

1634
01:16:05,900 --> 01:16:08,920
U mbagħad kollha ta 'l-netwerk tat-traffiku
li jiġri huwa dan.

1635
01:16:08,920 --> 01:16:11,230
$. GetJSON.

1636
01:16:11,230 --> 01:16:13,720
>> U bħala twarrib, sinjal dollaru huwa
biss notazzjoni shorthand.

1637
01:16:13,720 --> 01:16:16,860
Huwa tassew jQuery.getJSON.

1638
01:16:16,860 --> 01:16:21,520
Get lili biex JSON minn dan il-URL, u meta
it-talba taqa 'lura, sejħa dan

1639
01:16:21,520 --> 01:16:26,550
funzjoni u jgħaddu l-argument
kwalunkwe daħlu lura mill-server.

1640
01:16:26,550 --> 01:16:31,205
>> Allura fi kliem ieħor, jekk immur lura għall-
browser, u mmur lura għall quote.php,

1641
01:16:31,205 --> 01:16:35,590
dak browser tiegħi qed tagħmel huwa jkollna
din blokki ta 'data.

1642
01:16:35,590 --> 01:16:38,930
U meta mmur din il-paġna web hawn,
avviż jekk aħna minflok tmur għall-network

1643
01:16:38,930 --> 01:16:43,820
tab u ċar, u mbagħad it-tip fil-
xi ħaġa bħal GOOG għall-Google u Get

1644
01:16:43,820 --> 01:16:46,340
Quote, avviż il-paġna ma nbidilx.

1645
01:16:46,340 --> 01:16:50,990
Iżda talba HTTP saret, u liema
daħal lura hawn jekk inħarsu lejn il-

1646
01:16:50,990 --> 01:16:56,130
rispons huwa mazz sħiħ ta 'JSON
li aħna aċċessati finalment ma

1647
01:16:56,130 --> 01:16:58,070
din il-linja sempliċi hawn.

1648
01:16:58,070 --> 01:17:00,150
>> Data huwa dak li kien gotten
mis-server.

1649
01:17:00,150 --> 01:17:02,120
Prezz huwa l-isem tal-
ewlieni I jimpurtahom.

1650
01:17:02,120 --> 01:17:05,230
Allura data.price tagħti me dak.

1651
01:17:05,230 --> 01:17:07,540
>> Issa sadanittant, u dan
hija l-aħħar eżempju.

1652
01:17:07,540 --> 01:17:09,280
Tista 'tagħmel iżda aktar bil-paġna.

1653
01:17:09,280 --> 01:17:12,440
Wieħed fatt, ukoll tnejn.

1654
01:17:12,440 --> 01:17:14,780
Aħna jista 'jġib lura l-
tag, jekk tiftakar dan.

1655
01:17:14,780 --> 01:17:15,850
Li JavaScript.

1656
01:17:15,850 --> 01:17:17,110
Nistgħu nagħmlu dan.

1657
01:17:17,110 --> 01:17:17,690
Ferm eċċitanti.

1658
01:17:17,690 --> 01:17:18,800
Aħna ser tħalli li bħala cliffhanger.

1659
01:17:18,800 --> 01:17:21,590
>> Iżda aktar excitingly, inti tista '
tagħmel affarijiet bħal dan.

1660
01:17:21,590 --> 01:17:25,940
Jekk immur għall-ġeolokalizzazzjoni-1, jirriżulta
li Chrome jaf li aħna fil

1661
01:17:25,940 --> 01:17:30,672
lonġitudni latitudni 42.37. -71.10.

1662
01:17:30,672 --> 01:17:32,940
Allura hemm saħansitra aktar hemm
għad-dispożizzjoni tiegħek.

1663
01:17:32,940 --> 01:17:34,290
Iżda aktar fuq dik il-ġimgħa d-dieħla.

1664
01:17:34,290 --> 01:17:35,540
Ara inti Tnejn.

1665
01:17:35,540 --> 01:17:37,558