1
00:00:00,000 --> 00:00:11,736

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00:00:11,736 --> 00:00:16,626
>> [Daqq video]

3
00:00:16,626 --> 00:00:19,410
>> Trijonf -A ta matematiċi
u l-ħila mekkaniċi

4
00:00:19,410 --> 00:00:23,270
huwa dan awtomatika ġdida kbira
calculator fil-Harvard University.

5
00:00:23,270 --> 00:00:27,140
Problemi kumplessi fil-matematika
magħmula permezz tal-magna f'forma kodifikata

6
00:00:27,140 --> 00:00:31,710
fuq tape jiġu solvuti b'mod preċiż fil-
frazzjoni minuta mill-ħin mitlub

7
00:00:31,710 --> 00:00:32,819
għall-kalkolu tal-bniedem.

8
00:00:32,819 --> 00:00:44,280

9
00:00:44,280 --> 00:00:48,220
Iddisinjati biex iħaffu kull forma ta '
riċerka matematiċi u xjentifiċi,

10
00:00:48,220 --> 00:00:53,840
il-moħħ mekkaniku ġgant se jaħdmu
l-Istati Uniti Navy sat-tmiem tal-gwerra tal.

11
00:00:53,840 --> 00:01:03,620

12
00:01:03,620 --> 00:01:06,570
>> [END Daqq]

13
00:01:06,570 --> 00:01:08,590
>> DAVID J. Malan: Dan, huwa CS50.

14
00:01:08,590 --> 00:01:10,590
Il-passat kien maġika
post, imma jekk inti stajt qatt

15
00:01:10,590 --> 00:01:13,366
CROWLEY dak li mezz huwa
fl Harvard Science Center,

16
00:01:13,366 --> 00:01:16,150
huwa tabilħaqq parti mill-
Harvard Mark I, u huwa

17
00:01:16,150 --> 00:01:18,710
fuq display hemm issa
għall-ħafna snin.

18
00:01:18,710 --> 00:01:20,590
U dak li inti ser tara
inkorporati fil-sett problema

19
00:01:20,590 --> 00:01:24,416
wieħed huwa ħarsa wara l-kwinti
lejn dak li apparat ma, u ma,

20
00:01:24,416 --> 00:01:27,540
minn Professur Harry Lewis, li tkun fil
dipartiment xjenza tal-kompjuter hawn.

21
00:01:27,540 --> 00:01:29,440
Allura aktar fuq li fi ftit ftit.

22
00:01:29,440 --> 00:01:33,990
>> Imma llum aħna jibdew transizzjoni
mill-aħħar ġimgħa għal dan,

23
00:01:33,990 --> 00:01:37,290
u aħna ser iġibu aċċenn
ta 'ritratt wieħed hawn

24
00:01:37,290 --> 00:01:38,630
li attwalment pjuttost famużi.

25
00:01:38,630 --> 00:01:42,270
Hawn xi ħadd jaf liema dan
hawnhekk huwa fuq l-iskrin?

26
00:01:42,270 --> 00:01:43,880
Mill-inqas skond leġġenda.

27
00:01:43,880 --> 00:01:44,837
Yeah.

28
00:01:44,837 --> 00:01:45,920
UDJENZA: L-ewwel virus.

29
00:01:45,920 --> 00:01:49,570
DAVID J. Malan: Allura kien allegatament
l-ewwel bug attwali fil-kompjuter.

30
00:01:49,570 --> 00:01:52,490
Issa fir-realtà l-bug kelma,
għal żball fil-programm,

31
00:01:52,490 --> 00:01:55,250
ġie magħna għal xi
darba fid-dinja fiżika,

32
00:01:55,250 --> 00:01:58,190
u din kienet waħda mill-ewwel
ħinijiet dokumentati fejn xi ħadd fil-fatt

33
00:01:58,190 --> 00:02:02,280
mnittfa kamla kbir mill-Mark
Kompjuter II, poġġih fil-binder,

34
00:02:02,280 --> 00:02:05,006
u mbagħad rreġistrata, hija
bħala l-ewwel bug magħrufa

35
00:02:05,006 --> 00:02:06,630
li jkunu effettivament ġew misjuba fiżikament.

36
00:02:06,630 --> 00:02:10,104
Allura b'hekk iddaħħlet
dan in Lore lum.

37
00:02:10,104 --> 00:02:12,020
Kollox mill-aħħar
ġimgħa hija disponibbli online.

38
00:02:12,020 --> 00:02:14,840
Fil riżorsi partikolari li inti tista
mhux neċessarjament avviż, speċjalment

39
00:02:14,840 --> 00:02:15,881
jekk ġejjin hawn fil-persuna.

40
00:02:15,881 --> 00:02:20,230
Allura wieħed mill-fellows tagħlim kull
sena jagħmel sett canonical ta 'noti,

41
00:02:20,230 --> 00:02:22,010
hekk ikollok bżonn ma jżommux
rasek l-isfel, jippruvaw

42
00:02:22,010 --> 00:02:24,410
li tifformulaha mill-aktar xejn
li jista 'jiġri hawn fil-klassi.

43
00:02:24,410 --> 00:02:25,940
Allura jirrealizzaw li dawk
hekk imsejħa [? Scribd?] Noti

44
00:02:25,940 --> 00:02:29,350
huma online, ċertament l-pjastri u
kodiċi tas-sors li nużaw fil-klassi.

45
00:02:29,350 --> 00:02:31,436
Nagħmlu traskrizzjonijiet test sħiħ
disponibbli kif ukoll.

46
00:02:31,436 --> 00:02:34,310
Mela jekk inti vagament tiftakar xi
tul, u tixtieq tfittex it up ftit

47
00:02:34,310 --> 00:02:37,280
aktar faċilment, tirrealizza li kollha
ta 'dan huwa online jitfittex.

48
00:02:37,280 --> 00:02:38,930
Kif ukoll walkthroughs ukoll.

49
00:02:38,930 --> 00:02:42,710
Tabilħaqq, illum aħna tibda tħares lejn
lingwa ta 'programmar livell aktar baxx,

50
00:02:42,710 --> 00:02:45,290
dalwaqt ikunu magħrufa lilna
kif C, u huwa faċli ħafna

51
00:02:45,290 --> 00:02:48,820
li tip ta 'jintilfu wara biss ftit
mumenti ħin, u mbagħad it-tip ta wonder

52
00:02:48,820 --> 00:02:52,370
kif aħna fil-fatt ltqajna biex ftit aktar
eżempju kumpless mid-sempliċi.

53
00:02:52,370 --> 00:02:54,975
U hekk tirrealizza aħna ser ċirasa
pick matul il-klassi xi

54
00:02:54,975 --> 00:02:57,850
mill-eżempji rappreżentattivi, iżda
tirrealizza li tant aktar huwa wkoll

55
00:02:57,850 --> 00:03:01,140
disponibbli online sabiex inti tista 'taħdem
permezz ta 'dan fil-pass tiegħek,

56
00:03:01,140 --> 00:03:02,950
madankollu int l-aktar komdu.

57
00:03:02,950 --> 00:03:05,200
>> Iżda aħna jitħalla 'off ma'
programmi li kienu biss dan.

58
00:03:05,200 --> 00:03:09,690
So I ikklikkja l-bandiera aħdar,
u dak li ma dan il-programm do?

59
00:03:09,690 --> 00:03:10,710
Jgħid, hello, dinja.

60
00:03:10,710 --> 00:03:13,180
Jagħmel il-qattus jgħidu
bonjour fid-dinja ftit tiegħu

61
00:03:13,180 --> 00:03:15,990
fuq in-naħa ta 'fuq tax-xellug
tal user interface scratch s.

62
00:03:15,990 --> 00:03:18,810
Iżda aħna beda jintroduċi
xi terminoloġija ġimgħa li għaddiet.

63
00:03:18,810 --> 00:03:23,614
U għalhekk, affarijiet bħal dan we called liema?

64
00:03:23,614 --> 00:03:25,280
Liema jista 'jkun it-terminu ġeneriku għal dan?

65
00:03:25,280 --> 00:03:26,266
Yeah.

66
00:03:26,266 --> 00:03:28,210
Metodu jew dikjarazzjoni.

67
00:03:28,210 --> 00:03:29,280
Sure, huwa ta 'azzjoni.

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Agħmel dan.

69
00:03:30,140 --> 00:03:32,400
And yet kien hemm
forom oħra għall scratch,

70
00:03:32,400 --> 00:03:35,360
Minbarra dawn l-hekk imsejħa
dikjarazzjoni, kienu wkoll

71
00:03:35,360 --> 00:03:38,221
affarijiet bħal dan, li aħna msejħa dak?

72
00:03:38,221 --> 00:03:38,720
Yeah.

73
00:03:38,720 --> 00:03:39,634
Allura loop.

74
00:03:39,634 --> 00:03:42,050
U f'dan il-każ, dan il-ħaġa
jirrepeti, ovvjament, 10 darbiet.

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Hemm dejjem blokk.

76
00:03:43,040 --> 00:03:44,164
Hemm ftit oħrajn.

77
00:03:44,164 --> 00:03:48,309
U llum aħna qed tmur biex tara kif
tittraduċi dan għal dinja aktar moderna,

78
00:03:48,309 --> 00:03:50,850
jekk inti se, anki jekk huwa
ser jidhru ewwel daqqa t'għajn

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00:03:50,850 --> 00:03:52,024
li jkunu ferm iktar arcane.

80
00:03:52,024 --> 00:03:53,190
Iżda dawn kienu tabilħaqq loops.

81
00:03:53,190 --> 00:03:56,182
U allura għandna affarijiet simili
dan, li kellu dan forma,

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00:03:56,182 --> 00:03:57,515
u essenzjalment mistoqsijiet.

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00:03:57,515 --> 00:03:58,890
U aħna imsemmi dawn bħala dak?

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00:03:58,890 --> 00:03:59,762
>> UDJENZA: espressjoni Boolean.

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00:03:59,762 --> 00:04:00,320
>> DAVID J. Malan: Yeah.

86
00:04:00,320 --> 00:04:01,340
Espressjoni Boolean.

87
00:04:01,340 --> 00:04:04,502
Xi ħaġa li huwa jew vera jew
falza, iva jew le, wieħed jew żero,

88
00:04:04,502 --> 00:04:05,960
madankollu inti tixtieq li tara l-dinja.

89
00:04:05,960 --> 00:04:08,335
Iżda aħna msejħa dawk Boolean
espressjonijiet, u aħna plug tagħhom

90
00:04:08,335 --> 00:04:09,900
f'kundizzjonijiet, jew fergħat.

91
00:04:09,900 --> 00:04:12,170
U fid-dinja ta '
Scratch, kollox nicely

92
00:04:12,170 --> 00:04:15,460
interlocks f'termini ta 'għamla tagħha,
jekk jagħmel sens loġiku li jagħmlu dan,

93
00:04:15,460 --> 00:04:18,490
imma inti ma għandekx tieqaf fil biss
tagħmel ħaġa waħda kondizzjonalment,

94
00:04:18,490 --> 00:04:20,450
inti jista 'jkollhom proverbial
furketta fit-triq

95
00:04:20,450 --> 00:04:24,040
u tagħmel jew dan jew dak jekk
il-kundizzjoni hija vera jew le.

96
00:04:24,040 --> 00:04:26,040
U mbagħad, kif tkun taf tara,
jekk inti ma jkunux diġà,

97
00:04:26,040 --> 00:04:27,480
Tista 'anki bejta dawn il-blokok.

98
00:04:27,480 --> 00:04:32,110
Allura Scratch tikber biex timla l-forom
li inti tista 'tixtieq li daħħal fis dan,

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00:04:32,110 --> 00:04:35,330
sabiex inti tista 'attwalment tesprimi l-aktar
kwalunkwe loġika li inti tista 'tixtieq li tagħmel.

100
00:04:35,330 --> 00:04:38,220
>> Kliem issa ftit ta tħabbira
kemm hawn u New Haven.

101
00:04:38,220 --> 00:04:39,370
Allura sezzjonali jibda llum.

102
00:04:39,370 --> 00:04:42,120
Il-URL għal dan hija fuq li l-kors
website, għal dawk familjari.

103
00:04:42,120 --> 00:04:43,970
Sezzjonijiet ser ikun
opportunità li jiltaqgħu flimkien

104
00:04:43,970 --> 00:04:46,553
f'ambjent ħafna aktar intimi
minn [? Sanders?] Tippermetti,

105
00:04:46,553 --> 00:04:50,347
b'10 sa 20 klassi ma '
tagħlim sħabi fil binarji differenti,

106
00:04:50,347 --> 00:04:51,930
u b'rati differenti, jekk hekk jagħżlu.

107
00:04:51,930 --> 00:04:54,080
Tabilħaqq l-offerti kors
sezzjonijiet differenti

108
00:04:54,080 --> 00:04:57,340
għal dawk inqas komdi, aktar
komdu, u x'imkien bejniethom,

109
00:04:57,340 --> 00:04:59,860
u r-rwol ta 'thumb hawnhekk, huwa
hemm l-ebda definizzjoni formali,

110
00:04:59,860 --> 00:05:04,600
imma jekk int inqas komdi,
inti tip ta 'jafu.

111
00:05:04,600 --> 00:05:07,470
Int daqsxejn Intrepid dwar il
idea ta 'titjib marda, forsi, lura

112
00:05:07,470 --> 00:05:10,130
fil-klassi, jew li juru
sa fl bejn taqsima.

113
00:05:10,130 --> 00:05:12,770
Jekk inti kont qed programmazzjoni peress li inti
kienu sitt snin, aktar komda,

114
00:05:12,770 --> 00:05:13,400
forsi lilek.

115
00:05:13,400 --> 00:05:16,150
U jekk huwa tip ta toss-up,
dan huwa eżattament dak li l-bejniethom

116
00:05:16,150 --> 00:05:17,190
huwa maħsub li jkun.

117
00:05:17,190 --> 00:05:18,410
>> Issa, fil-frattemp,
għal klassi dan id-daqs,

118
00:05:18,410 --> 00:05:21,326
hija tieħu us żmien pjuttost twil għat-taqsima
kulħadd, hekk aħna hekk imsejħa,

119
00:05:21,326 --> 00:05:24,030
sezzjonijiet super, ġejjin up dan
weekend u ġimgħa d-dieħla kmieni,

120
00:05:24,030 --> 00:05:26,570
hekk tagħti ħarsa fuq il-websajt tal-kors ta
għal dawk li huma naturalment wiesgħa,

121
00:05:26,570 --> 00:05:28,610
u wkoll iffilmjati għal dawk
li ma jkunux jistgħu jgħamluha.

122
00:05:28,610 --> 00:05:33,470
U sezzjonijiet nfushom se tibda
fil-ġimgħa tlieta mill CS50 indiċi żero.

123
00:05:33,470 --> 00:05:35,880
Problema sett 0 diġà
fuq il-websajt il-kors tal.

124
00:05:35,880 --> 00:05:40,010
U jirrealizzaw li inti do jkollhom
disat ijiem tard dan is-semestru.

125
00:05:40,010 --> 00:05:43,240
Allura dan huwa upgrade mill-aħħar
sena, meta kellna ħamest ijiem tard.

126
00:05:43,240 --> 00:05:46,210
>> Mela jekk int mintix,
għandna disa settijiet problema.

127
00:05:46,210 --> 00:05:53,200
Inti għandek disa tard ġranet, li kull waħda minnhom
inti tista 'biss jonfqu wieħed fil-ġimgħa fuq.

128
00:05:53,200 --> 00:05:56,089
Li effettivament tagħmel id ta '
il-problema settijiet il-ġimgħa dovuta,

129
00:05:56,089 --> 00:05:58,630
iżda l-għan huwa li l-ftit
daqsxejn ta 'pressjoni psikoloġika

130
00:05:58,630 --> 00:06:01,100
fuqek biex nipprova nikseb
affarijiet fil-Ħamis

131
00:06:01,100 --> 00:06:03,960
għaliex kif inti dalwaqt se jiskopru,
għall-aħjar jew għall-agħar, l-aktar

132
00:06:03,960 --> 00:06:07,820
kollox fid-dinja software jispiċċa
tieħu ħafna itwal milli suppost tantiċipa.

133
00:06:07,820 --> 00:06:10,620
Allura iqisu li jkun sort
ta 'opportunità biex tgħin

134
00:06:10,620 --> 00:06:13,880
yourself mira Ħamis
imma jieħdu kumdità peress li, iva,

135
00:06:13,880 --> 00:06:14,950
kollox huwa dovut il-ġimgħa.

136
00:06:14,950 --> 00:06:17,590
U jekk inti tippreżenta minnhom fuq
Il-Ħamis, li mill-isbaħ.

137
00:06:17,590 --> 00:06:21,020
M'hemm l-ebda punti ta 'bonus jew extra
kreditu biex jintlaħqu dik l-iskadenza.

138
00:06:21,020 --> 00:06:23,250
Huwa maħsub li jkun crutch biss.

139
00:06:23,250 --> 00:06:25,810
>> U ħinijiet tal-uffiċċju, kemm
hawn u fi New Haven,

140
00:06:25,810 --> 00:06:28,840
fil-persuna, jekk inti tixtieq li
jiltaqa 'ma' xi wieħed mill-korsijiet tagħna

141
00:06:28,840 --> 00:06:31,060
tagħlim fellows u CAs għall-għajnuna.

142
00:06:31,060 --> 00:06:31,640
>> Kull dritt.

143
00:06:31,640 --> 00:06:33,110
Allura issa, ejja jagħmlu dan aktar reali.

144
00:06:33,110 --> 00:06:35,470
U għal mument li għaddej biex tibda
li jiksbu ftit aktar arcane, iżda ħafna

145
00:06:35,470 --> 00:06:37,310
malajr nhar il-Ġimgħa u
ġimgħa d-dieħla se nkunu

146
00:06:37,310 --> 00:06:41,230
jistgħu jagħmlu dan ħafna aktar minn
nistgħu s'issa fil Scratch.

147
00:06:41,230 --> 00:06:44,350
Allura aħna introdotti kodiċi aħħar
ġimgħa, għalkemm pictoral.

148
00:06:44,350 --> 00:06:45,620
Kien biċċiet puzzle.

149
00:06:45,620 --> 00:06:48,800
U aħna formalizzata li huwa
xi ħaġa imsejħa source code,

150
00:06:48,800 --> 00:06:50,330
iżda ma look like?

151
00:06:50,330 --> 00:06:52,550
Ukoll, deher ftit
xi ħaġa bħal din.

152
00:06:52,550 --> 00:06:55,410
U, fil-fatt, biss biex tip ta '
tease fejn nistgħu mmorru ma 'dan.

153
00:06:55,410 --> 00:06:57,800
Jien ser jimxi 'l quddiem u
jiftħu tieqa hawn,

154
00:06:57,800 --> 00:06:59,810
u jien biss ser jagħżlu File Ġdid.

155
00:06:59,810 --> 00:07:03,200
U jien ser tiffranka dan il-fajl
bħala xi ħaġa bħal bonjour dot c.

156
00:07:03,200 --> 00:07:05,700
Aktar dwar din l-għażla ta '
kliem fil ftit mument.

157
00:07:05,700 --> 00:07:08,630
U dan huwa kif xi ħadd jista
tmur dwar kitba ta 'programm.

158
00:07:08,630 --> 00:07:13,990
Inkludi I standard / O dot h, prinċipali int
null, u mbagħad miftuħa kaboċċi Brace, qrib

159
00:07:13,990 --> 00:07:19,430
kaboċċi Brace, printf bonjour dinja comma,
backslash n, punto virgola, Save, isir.

160
00:07:19,430 --> 00:07:19,930
OK.

161
00:07:19,930 --> 00:07:21,670
Stajt bil-miktub ewwel tiegħi
programm, iżda li għaddej

162
00:07:21,670 --> 00:07:23,878
li jkun oerhört underwhelmed
għaliex meta I attwalment

163
00:07:23,878 --> 00:07:27,352
run dan il-programm, naturalment,
billi l-ewwel kitba jagħmlu hello,

164
00:07:27,352 --> 00:07:30,310
u mbagħad dot slash hello, u aħna ser
jgħaddu din fil ħafna aktar dettall

165
00:07:30,310 --> 00:07:31,730
fil-mument, li kollox ma.

166
00:07:31,730 --> 00:07:33,270
Ma pop miftuħa kwalunkwe tieqa.

167
00:07:33,270 --> 00:07:35,070
Ma tagħmel xejn
partikolarment fancy.

168
00:07:35,070 --> 00:07:38,830
Kull ma huwa dak I told li
tagħmel, imma kif nistgħu jiksbu għal dak?

169
00:07:38,830 --> 00:07:40,560
U kif nistgħu nibnu fuq dak?

170
00:07:40,560 --> 00:07:43,430
Well, ejja jintroduċu xi ftit
kunċetti differenti hawn.

171
00:07:43,430 --> 00:07:47,170
>> Allura wieħed, aħna qed madwar biex tibda
permezz ta 'programm imsejjaħ kompilatur.

172
00:07:47,170 --> 00:07:51,470
Teżisti kompilatur għall Mac OS, Windows,
Linux, kull numru ta 'sistemi operattivi,

173
00:07:51,470 --> 00:07:54,540
u aħna ser dalwaqt jintroduċu inti għad-
ambjent li aħna se tkun qed tuża,

174
00:07:54,540 --> 00:07:57,410
iżda kompilatur hija biss ġenerali
tul għal biċċa ta 'softwer

175
00:07:57,410 --> 00:08:01,940
li jieħu source code u
tipproduċi object code minnha.

176
00:08:01,940 --> 00:08:03,940
Fi kliem ieħor, jekk inti
jkollhom bħala input sors tiegħek

177
00:08:03,940 --> 00:08:08,250
kodiċi, xi ħaġa bħal dak I biss ittajpjat,
finalment tipproduċi object code.

178
00:08:08,250 --> 00:08:11,780
U object code huwa verament ftit
mod fancy ta 'tgħid outputs

179
00:08:11,780 --> 00:08:12,926
s żero u s wieħed.

180
00:08:12,926 --> 00:08:14,800
Fi kliem ieħor, is-sors
kodiċi, anki jekk huwa

181
00:08:14,800 --> 00:08:17,240
ser tfittex arcane ftit,
u ftit inqas ħbiberija

182
00:08:17,240 --> 00:08:19,590
minn Scratch ewwel daqqa t'għajn,
huwa inqas xi ħaġa

183
00:08:19,590 --> 00:08:21,120
li aħna bnedmin jistgħu jifhmu.

184
00:08:21,120 --> 00:08:24,360
Huwa tip ta 'jistenna u ħsejjes simili
Ingliż anki jekk huwa konċiż ħafna.

185
00:08:24,360 --> 00:08:28,040
Billi programmazzjoni tal żero u
wieħed, kif predeċessuri tagħna kellha tagħmel,

186
00:08:28,040 --> 00:08:30,920
xi snin ilu, ma kienx
daħla gost.

187
00:08:30,920 --> 00:08:33,710
And yet, dan huwa dak li l-
kompjuter xorta jifhem.

188
00:08:33,710 --> 00:08:37,010
Allura kompilatur gets us mill
kodiċi tas-sors ta 'oġġezzjoni kodiċi.

189
00:08:37,010 --> 00:08:39,860
Huwa simili jiftħu fajl bl-
kompilatur, u meta inti isalvawh,

190
00:08:39,860 --> 00:08:41,419
inti tikseb dawk żerijiet u dawk.

191
00:08:41,419 --> 00:08:43,419
Allura aħna ser tara kif tagħmel
li fi ftit mument.

192
00:08:43,419 --> 00:08:47,400
>> Imma ejja issa jippruvaw jipprovdu
pont bejn ġimgħa li għaddiet u dan,

193
00:08:47,400 --> 00:08:50,660
sabiex anke kif aħna nikseb mdendla
fuq affarijiet simili ċingi kaboċċi,

194
00:08:50,660 --> 00:08:54,100
u semicolons, u parentesi, u
kollha ta 'dawn intellettwalment interessanti

195
00:08:54,100 --> 00:08:57,620
aspetti ta 'programmazzjoni, li ħafna
jifhem vjaġġ nies up kmieni,

196
00:08:57,620 --> 00:09:00,930
jirrealizzaw li kollha tal-ideat
illum, huma l-istess kif l-aħħar.

197
00:09:00,930 --> 00:09:03,975
Allura aħħar, rajna dan l-eżempju
hawn, program Hello World.

198
00:09:03,975 --> 00:09:07,500
Well, jibdew illum, jekk irridu
biex jimplimenta l-istess programm,

199
00:09:07,500 --> 00:09:10,800
li għaddej biex tfittex
ftit xi ħaġa bħal din.

200
00:09:10,800 --> 00:09:14,040
U aħna ser jispjegaw qabel twil dak int,
u prinċipali, u bla effett, u kollha ta 'dak

201
00:09:14,040 --> 00:09:18,770
huwa, iżda mill-inqas nara hawn
diġà l-Hello World familjari.

202
00:09:18,770 --> 00:09:20,860
>> Sadanittant, affarijiet simili
funzjoni, jiġifieri hello,

203
00:09:20,860 --> 00:09:23,570
huwa ferm sempliċiment se tkun
dikjarazzjoni sempliċi ħafna bħal dan.

204
00:09:23,570 --> 00:09:26,930
Printf bonjour dinja, b'xi
kwotazzjonijiet, bil-backslash,

205
00:09:26,930 --> 00:09:29,780
bil-punto virgola, iżda
aktar fuq li fil-ġejjieni.

206
00:09:29,780 --> 00:09:34,066
Linji, sadanittant, dan huwa loop li,
naturalment, jgħid bonjour dinja dejjem,

207
00:09:34,066 --> 00:09:36,690
u dan wieħed għaddej biex tfittex
ftit weirder milli fl-aħħar,

208
00:09:36,690 --> 00:09:39,530
imma jekk jien ngħid xi ħaġa
simili, filwaqt veru, I

209
00:09:39,530 --> 00:09:44,050
tista 'mbagħad jistampa Hello dinja
ġdid u għal darb'oħra u għal darb'oħra u għal darb'oħra.

210
00:09:44,050 --> 00:09:46,660
U allura kemm tista 'xorta
ta tibda jiddeduċu hawn,

211
00:09:46,660 --> 00:09:49,070
din il-konvenzjoni ta 'użu
braces kaboċċi huwa tip

212
00:09:49,070 --> 00:09:52,050
ta 'prodotti simili tħaddan l-
linja indentati ta 'kodiċi hemmhekk.

213
00:09:52,050 --> 00:09:55,840
Il-linja printf tal-kodiċi ferm simili
l-biċċa puzzle isfar up hawn fuq.

214
00:09:55,840 --> 00:09:58,740
Allura aħna ma tkunx qed tmur biex ngħid dejjem,
aħna qed tmur biex ngħid filwaqt veru,

215
00:09:58,740 --> 00:10:01,020
iżda aħna ser tara għaliex dan huwa biss daqsxejn.

216
00:10:01,020 --> 00:10:04,210
>> Sadanittant, jekk ikollna loop bħal dan,
fejn inti jirrepetu xi ħaġa finit

217
00:10:04,210 --> 00:10:07,730
żminijiet numru, dan wieħed wisq huwa
se jieħu ftit jkollna użati

218
00:10:07,730 --> 00:10:12,820
li, iżda li għaddej biex ngħid għal int
i gets zero, i inqas minn 10, i ++,

219
00:10:12,820 --> 00:10:14,056
u mbagħad printf mill-ġdid.

220
00:10:14,056 --> 00:10:15,430
Iżda hemm għaddej li jkun mudelli.

221
00:10:15,430 --> 00:10:18,434
U għal dawk minnkom familjari
ma AP Computer Science, jew Java,

222
00:10:18,434 --> 00:10:21,100
jew kwalunkwe numru ta 'lingwi oħra,
kważi kollha ta 'dawn constructs

223
00:10:21,100 --> 00:10:23,820
s'issa għandha tfittex l-aktar familjari.

224
00:10:23,820 --> 00:10:24,680
>> Allura varjabbli.

225
00:10:24,680 --> 00:10:29,270
Allura hawnhekk silta Scratch sempliċi li
tistabbilixxi varjabbli msejħa counter għal żero,

226
00:10:29,270 --> 00:10:33,150
u mbagħad dejjem jgħid il-counter, u
allura tbiddel l-counter minn wieħed.

227
00:10:33,150 --> 00:10:37,030
Allura li jibda bil żero,
u mbagħad wieħed, tnejn, tlieta.

228
00:10:37,030 --> 00:10:42,560
Ukoll, kif jista aħna jintroduċu dik fil
din il-lingwa l-ġdida ftit simili?

229
00:10:42,560 --> 00:10:45,460
Counter int ugwali
żero, filwaqt vera, li

230
00:10:45,460 --> 00:10:48,100
huwa l-istess idea minn qabel l
li jagħmlu xi ħaġa għal dejjem,

231
00:10:48,100 --> 00:10:49,530
u jien biss ser printf.

232
00:10:49,530 --> 00:10:53,310
U issa huwa jkollna ftit stramba,
mija i, iżda aktar fuq li li ġejjin,

233
00:10:53,310 --> 00:10:55,140
iżda dawn l-ideat huma eżattament l-istess.

234
00:10:55,140 --> 00:10:58,820
Aħna biss issa jridu jaderixxu ma
l-sintassi li l-kompjuter huwa

235
00:10:58,820 --> 00:11:00,010
ser domanda minna.

236
00:11:00,010 --> 00:11:04,620
>> Espressjoni Boolean, xi ħaġa bħal
SX inqas minn y, jew x inqas minn y,

237
00:11:04,620 --> 00:11:06,354
uy inqas minn z.

238
00:11:06,354 --> 00:11:09,270
Huwa ser tfittex ftit xi ħaġa
bħal dan, ma parentesi biss

239
00:11:09,270 --> 00:11:13,020
bħal fil-matematika għal miżura tajba għal ftit
jiżguraw li l-ordni ta 'operazzjonijiet

240
00:11:13,020 --> 00:11:14,750
huwa kif għandna l-ħsieb.

241
00:11:14,750 --> 00:11:15,600
U issa, kundizzjonijiet.

242
00:11:15,600 --> 00:11:21,220
Mela jekk x inqas minn y, jgħidu x hija inqas
minn y, inkella jekk x huwa akbar minn y,

243
00:11:21,220 --> 00:11:26,020
jgħidu x huwa akbar minn y, inkella
loġikament, x irid ikun ugwali għal y.

244
00:11:26,020 --> 00:11:28,710
Allura inti tista 'timplimenta
xi ħaġa bħal din fil Scratch,

245
00:11:28,710 --> 00:11:31,230
jew inti tista 'timplimenta
it f'dan sintassi.

246
00:11:31,230 --> 00:11:35,090
U għal darb'oħra, il-braces kaboċċi huma tip ta '
tagħti l-istess forma bħall-puzzle

247
00:11:35,090 --> 00:11:40,750
biċċiet, iżda l-sintassi, issa, huwa forsi
jibdew isegwu xi mudelli.

248
00:11:40,750 --> 00:11:42,910
>> Allura, dak ma dan tagħtina hawn?

249
00:11:42,910 --> 00:11:45,260
Allura aħna qed lura mbagħad fl program prinċipali tagħna.

250
00:11:45,260 --> 00:11:47,930
Ejja attwalment, issa,
tagħmel xi ħaġa ma 'dan.

251
00:11:47,930 --> 00:11:50,660
Allura f'dan il-ħafna ewwel
linja naraw qawwija jinkludu,

252
00:11:50,660 --> 00:11:53,160
I standard / O, dot h, u
mbagħad ftit angolu stramb

253
00:11:53,160 --> 00:11:57,330
parentesi taħt dak. int prinċipali
null, u mbagħad printf bonjour dinja.

254
00:11:57,330 --> 00:11:58,200
Hekk biss tieħu pass.

255
00:11:58,200 --> 00:12:02,440
Xi ħadd li qatt programmati qabel,
mill-inqas jispjegaw waħda minn dawn il-linji.

256
00:12:02,440 --> 00:12:04,490
Bl-użu forsi xi wħud
l-lingwaġġ tal-ġimgħa li għaddiet.

257
00:12:04,490 --> 00:12:06,942
X'inhu printf, per eżempju?

258
00:12:06,942 --> 00:12:07,442
Yeah.

259
00:12:07,442 --> 00:12:08,410
>> UDJENZA: [inaudible]

260
00:12:08,410 --> 00:12:08,610
>> DAVID J. Malan: Yeah.

261
00:12:08,610 --> 00:12:11,380
Huwa funzjoni, jew stqarrija,
minn terminoloġija ġimgħa li għaddiet.

262
00:12:11,380 --> 00:12:13,470
U huwa azzjoni
li qed jagħmel xi ħaġa.

263
00:12:13,470 --> 00:12:15,855
Issa din il-funzjoni, jew
din id-dikjarazzjoni, ma

264
00:12:15,855 --> 00:12:17,550
jidher li jieħdu xi tip ta 'input?

265
00:12:17,550 --> 00:12:20,080

266
00:12:20,080 --> 00:12:24,380
U f'liema sens ma huwa
jidhru li jieħdu input, jekk iva?

267
00:12:24,380 --> 00:12:26,180
Input, liema do I jfisser minn dak?

268
00:12:26,180 --> 00:12:26,720
Yeah.

269
00:12:26,720 --> 00:12:27,595
>> UDJENZA: [inaudible]

270
00:12:27,595 --> 00:12:30,565

271
00:12:30,565 --> 00:12:31,440
DAVID J. Malan: Yeah.

272
00:12:31,440 --> 00:12:34,890
Allura Scratch out biċċiet puzzle ftit
fejn inti tista parametrize dan.

273
00:12:34,890 --> 00:12:37,980
Inti tista 'tgħid l-irrepeti
blokk kif ħafna drabi li jirrepeti,

274
00:12:37,980 --> 00:12:40,320
b'tali mod li kien input ta
xorta, u bħad Scratch

275
00:12:40,320 --> 00:12:43,060
kellhom placeholder ftit abjad
għan-numru inti tip fil-

276
00:12:43,060 --> 00:12:45,810
hekk ukoll nużaw f'dan
parentesi dinja test

277
00:12:45,810 --> 00:12:49,910
biex tagħtina din il-forma ċirkolari
li fih nistgħu plagg input tagħna.

278
00:12:49,910 --> 00:12:53,180
Wara kollox, għexieren ta 'snin ilu
meta din il-lingwa, jissejjaħ C,

279
00:12:53,180 --> 00:12:55,950
kienet ivvintata ebda wieħed
antiċipat hija waħda minna,

280
00:12:55,950 --> 00:12:59,420
dawn xi snin wara, aħna'd
jridu funzjoni li tgħid bonjour.

281
00:12:59,420 --> 00:12:59,920
Dritt?

282
00:12:59,920 --> 00:13:02,880
Hija d jkun sbieħ jekk kien hemm
biċċa puzzle, jew kliem ewlenin,

283
00:13:02,880 --> 00:13:05,502
li sejjaħ hello, li
litteralment biss jgħid bonjour.

284
00:13:05,502 --> 00:13:06,460
Iżda aħna ma bżonn li.

285
00:13:06,460 --> 00:13:09,320
Jista 'jkollna xi ħaġa ferm aktar baxxa
livell, bħal print ġeneriku

286
00:13:09,320 --> 00:13:12,760
kmand, li jieħu input,
u stampi xi rridu.

287
00:13:12,760 --> 00:13:14,960
Allura avviż issa l-mudell
li se jibdew jitfaċċaw.

288
00:13:14,960 --> 00:13:19,310
Paren miftuħa, paren qrib hija
apparentement tħaddan l-input,

289
00:13:19,310 --> 00:13:21,770
u mbagħad nara double
kwotazzjonijiet fuq iż-żewġ truf.

290
00:13:21,770 --> 00:13:25,110
Għad hemm backslash stramb
n, iżda nisperaw issa int

291
00:13:25,110 --> 00:13:29,900
tista 'tibda Ħares għall-inqas li
printf qed tieħu f'xi forma ta 'input.

292
00:13:29,900 --> 00:13:31,850
Mhux faċli għall-utent kif
Scratch, iżda huwa biss

293
00:13:31,850 --> 00:13:34,920
simili li jkollhom pplaggjata xi valur hemmhekk.

294
00:13:34,920 --> 00:13:38,306
>> Kull dritt, issa ejja fil-fatt
tagħmel xi ħaġa ma 'dan.

295
00:13:38,306 --> 00:13:40,930
Allura xi wħud minnkom tista 'taf minn
li shopped il-klassi qabel,

296
00:13:40,930 --> 00:13:42,638
ċċettjaw mal-ħbieb,
li għal ħafna snin

297
00:13:42,638 --> 00:13:44,590
użajna xi ħaġa imsejħa
l-appliance CS50.

298
00:13:44,590 --> 00:13:49,160
Dan kien terminu jiddeskrivi teknoloġija
imsejjaħ il-magna virtwali, li

299
00:13:49,160 --> 00:13:51,870
hija biċċa ta 'softwer li tiegħek
predeċessuri se tniżżel off

300
00:13:51,870 --> 00:13:53,360
websajt tal-kors tal b'xejn.

301
00:13:53,360 --> 00:13:56,550
Huma wkoll tniżżel biċċa ħielsa
ta 'softwer imsejjaħ hypervisor,

302
00:13:56,550 --> 00:14:00,590
xi ħaġa imsejħa bħal VMware,
jew VirtualBox, jew kwalunkwe numru

303
00:14:00,590 --> 00:14:04,450
ta 'għodod oħra, u fuq tagħhom Mac jew PC
jew kwalunkwe kompjuter li kellhom sena li għaddiet

304
00:14:04,450 --> 00:14:06,620
u fl-aħħar snin, huma
jista 'jirdoppja ikklikkja ikona

305
00:14:06,620 --> 00:14:08,860
biex imexxu dan is-software
imsejjaħ il-hypervisor.

306
00:14:08,860 --> 00:14:12,220
U allura ġewwa ta 'dak il-programm
huma tiftaħ il appliance CS50.

307
00:14:12,220 --> 00:14:14,710
U l-effett kien li
jekk predeċessur tal tiegħek

308
00:14:14,710 --> 00:14:17,780
kien għaddej Mac OS jew
Windows, hu jew hi mbagħad

309
00:14:17,780 --> 00:14:22,910
sussegwentement kellhom tieqa ġdida fuq tagħhom
screen running ambjent CS50 s.

310
00:14:22,910 --> 00:14:27,370
Allura magna virtwali ihallik run wieħed
sistema operattiva ġewwa ta 'ieħor,

311
00:14:27,370 --> 00:14:28,785
u dan huwa eżattament dak li għamilna.

312
00:14:28,785 --> 00:14:31,410
Matul parti kbira naturalment il-we
jużaw sistema operattiva imsejħa

313
00:14:31,410 --> 00:14:34,070
Linux, speċifikament
Ubuntu Linux, u dan

314
00:14:34,070 --> 00:14:37,590
huwa mod tajjeb ħafna fl-aħħar snin ta '
jagħmlu ċert li kulħadd fil-kors

315
00:14:37,590 --> 00:14:38,840
biss kellhom l-istess ambjent.

316
00:14:38,840 --> 00:14:41,339
U inti tista 'tuża kwalunkwe tip ta'
kompjuter li inti fil-fatt tixtieq.

317
00:14:41,339 --> 00:14:43,930
Fost il-aspetti negattivi, għalkemm,
kieku ma kienx bħal żewġ gigabytes

318
00:14:43,930 --> 00:14:45,480
li tniżżel dan il-ħaġa.

319
00:14:45,480 --> 00:14:50,310
Hija ma neċessarjament xogħol super sew fit
persuni li kompjuters li forsi biss

320
00:14:50,310 --> 00:14:54,570
kellhom GIG jew hekk ta 'RAM, jew le
wisq gigahertz ta 'veloċità CPU,

321
00:14:54,570 --> 00:14:56,750
u għalhekk din is-sena, għal
dan u raġunijiet oħra,

322
00:14:56,750 --> 00:14:59,140
li aħna qed transizzjonijiet
li dan l-ambjent.

323
00:14:59,140 --> 00:15:03,730
L-hekk imsejħa CS50 IDE, li hija
ibbażati fuq software b'sors miftuħ,

324
00:15:03,730 --> 00:15:07,380
u pjattaforma appoġġjati
li kumpanija msejħa Cloud9

325
00:15:07,380 --> 00:15:11,110
jappoġġja fl-Ewropa, li
jippermetti li essenzalment għandhom

326
00:15:11,110 --> 00:15:15,770
l-istess ambjent eżatt bħal fil
snin li għaddew, iżda fil-sħaba hekk imsejħa.

327
00:15:15,770 --> 00:15:17,532
>> Allura x'inhi l-sħaba?

328
00:15:17,532 --> 00:15:20,480
You ħadthom probabbilment għafast
icon tagħha fuq Mac tiegħek jew PC.

329
00:15:20,480 --> 00:15:22,210
X'inhu l-sħaba?

330
00:15:22,210 --> 00:15:22,709
Yeah?

331
00:15:22,709 --> 00:15:25,880

332
00:15:25,880 --> 00:15:26,780
A louder ftit.

333
00:15:26,780 --> 00:15:30,510

334
00:15:30,510 --> 00:15:31,010
Yeah.

335
00:15:31,010 --> 00:15:33,770
Huwa biss mazz ta 'kompjuters
x'imkien ieħor li jaħżen id-data u run

336
00:15:33,770 --> 00:15:34,880
softwer u simili.

337
00:15:34,880 --> 00:15:39,390
Allura huwa verament ftit l-kelma de
jure deskritti [? rentable?]

338
00:15:39,390 --> 00:15:40,930
kompjuters li jgħixu xi mkien ieħor.

339
00:15:40,930 --> 00:15:42,810
Li inti, lilek innifsek,
mhux bilfors stess.

340
00:15:42,810 --> 00:15:45,256
Allura meta data tiegħek, jew tiegħek
programmi, huma fil-sħaba,

341
00:15:45,256 --> 00:15:47,630
hija biss ifisser li huwa fuq xi ħadd
ieħor tal-kompjuters bnadi oħra,

342
00:15:47,630 --> 00:15:50,510
u mhux, x'aktarx, fuq tiegħek
laptop fiżika jew desktop.

343
00:15:50,510 --> 00:15:52,990
U hekk dan huwa dak CS50 IDE issa huwa.

344
00:15:52,990 --> 00:15:55,670
>> Minn issa inti ser tmur għal ċertu
URL li inti se ddaħħal

345
00:15:55,670 --> 00:16:00,090
li, fil-problema stabbilixxa l-1, aktar tard din
ġimgħa, li mbagħad, wara qtugħ fi,

346
00:16:00,090 --> 00:16:01,480
jagħtik dan l-ambjent.

347
00:16:01,480 --> 00:16:03,896
U ħafna Scratch bħal kellhom
bordijiet differenti ftit involuti,

348
00:16:03,896 --> 00:16:06,030
hekk ukoll il IDE CS50 i jkollhom eżattament dan.

349
00:16:06,030 --> 00:16:09,480
Min-naħa ta 'fuq tax-xellug hawn, int
ser tara fajl browser familjari.

350
00:16:09,480 --> 00:16:11,930
Allura kull tal-fajls li inti
jitqiegħed fis dan l-ambjent

351
00:16:11,930 --> 00:16:13,346
huma biss se jiġu elenkati hemmhekk.

352
00:16:13,346 --> 00:16:14,350
Fajls u folders.

353
00:16:14,350 --> 00:16:16,790
Fuq il-quċċata dritt hawn,
int ser tara post

354
00:16:16,790 --> 00:16:18,420
fejn inti tista 'attwalment jikteb il-kodiċi tiegħek.

355
00:16:18,420 --> 00:16:21,860
Inizjalment fis-C, aktar tard fil-
tul fil-PHP u JavaScript,

356
00:16:21,860 --> 00:16:24,739
u, forsi għal finali
proġetti, Ruby jew Java jew Python

357
00:16:24,739 --> 00:16:27,280
jew kwalunkwe numru ta 'lingwi huma
appoġġjati f'dan l-ambjent.

358
00:16:27,280 --> 00:16:30,130
Mhuwiex fil-livelli kollha marbuta
li CS50 speċifikament.

359
00:16:30,130 --> 00:16:33,390
>> U mbagħad fil-kantuniera t'isfel hawn,
speċjalment għal dawk aktar komda,

360
00:16:33,390 --> 00:16:35,590
għandek xi ħaġa
imsejħa tieqa terminal.

361
00:16:35,590 --> 00:16:38,770
U dan il-tieqa terminal tippermetti
inti jesegwixxu kwalunkwe kmand li inti

362
00:16:38,770 --> 00:16:40,860
tixtieq f'dan l-ambjent sħaba.

363
00:16:40,860 --> 00:16:42,860
Huwa jippermettilek li jinstallaw
kwalunkwe softwer addizzjonali

364
00:16:42,860 --> 00:16:46,810
li trid għax għandek hekk imsejħa
għeruq, jew amministratur privileġġi.

365
00:16:46,810 --> 00:16:49,930
Allura fi kliem ieħor, anki jekk dan
aħħar mill-aħħar ospitat fil-sħaba,

366
00:16:49,930 --> 00:16:52,400
u anke jekk aħna għandna
ssimplifikatha biex tkun sa ċertu punt

367
00:16:52,400 --> 00:16:57,110
awtomatikament, litteralment introduzzjoni,
grazzi għall Dan Armendáriz, u Dino,

368
00:16:57,110 --> 00:17:01,070
u Dan Bradley fit-tim CS50 matul l-
passat ħafna xhur, inqas komdi

369
00:17:01,070 --> 00:17:05,140
modalità li l-ġlud ħafna tal-
distrazzjonijiet inizjalment konfuża.

370
00:17:05,140 --> 00:17:10,119
Kollox teżisti biex
jirrappreżentaw sistema tal-kompjuter tipiku

371
00:17:10,119 --> 00:17:12,319
li inti tista 'tuża fid-dinja reali.

372
00:17:12,319 --> 00:17:15,640
>> Allura dak li ma dan kollu jfisser, u
x'nistgħu attwalment tagħmel magħha?

373
00:17:15,640 --> 00:17:19,124
Ejja attwalment tieħu Peek fuq programm.

374
00:17:19,124 --> 00:17:21,290
Hekk jien ser tiftaħ is-
ambjent attwali hawnhekk,

375
00:17:21,290 --> 00:17:23,894
li huwa biss Chrome tagħna
browser, li jistgħu jkunu Firefox,

376
00:17:23,894 --> 00:17:26,640
jista 'jkun Internet Explorer,
jew xi browser oħra kif ukoll.

377
00:17:26,640 --> 00:17:28,400
Huwa sħiħa skrinjati hawn għall-mument.

378
00:17:28,400 --> 00:17:31,580
U nixtieq li attwalment tease
apparti dak li dan il-programm kien.

379
00:17:31,580 --> 00:17:36,170
Mela ejja tagħti ħarsa, billi zooming up
top, fil dak li għamilt, u kif I ltqajna hawn.

380
00:17:36,170 --> 00:17:38,315
Allura hawnhekk dawk eżatt
istess linji ta 'kodiċi.

381
00:17:38,315 --> 00:17:40,440
Allura dan huwa l-istqarrija,
kif inti issemma qabel.

382
00:17:40,440 --> 00:17:42,580
Il-funzjoni li tgħid bonjour.

383
00:17:42,580 --> 00:17:45,870
Il ċingi kaboċċi, fuq
linja erba 'u linja sitt,

384
00:17:45,870 --> 00:17:49,290
preżumibbilment tip ta 'pakkett
dik il-linja li jassoċja

385
00:17:49,290 --> 00:17:50,890
bl-essenza tal-programm tiegħi.

386
00:17:50,890 --> 00:17:54,890
Allura fil-fatt, dan il-keyword prinċipali,
dan huwa up hemm fuq il-linja tlieta,

387
00:17:54,890 --> 00:17:59,450
inti tista 'taħseb li bħala l-ekwivalenti
ta 'li meta bandiera aħdar għafast,

388
00:17:59,450 --> 00:18:01,080
blokk fil Scratch.

389
00:18:01,080 --> 00:18:05,280
Allura li kollox għandna hawnhekk, huwa meta
bandiera aħdar għafast, jistampa, jew jgħidu,

390
00:18:05,280 --> 00:18:06,700
bonjour dinja.

391
00:18:06,700 --> 00:18:11,210
>> Imma ejja tagħti raden, issa, b'liema
dan l-ewwel, linja aktar arcane, huwa.

392
00:18:11,210 --> 00:18:15,100
Sharp jinkludu, open angolata
parentesi, I standard / O dot h,

393
00:18:15,100 --> 00:18:17,320
qrib bracket angolata.

394
00:18:17,320 --> 00:18:19,850
X'inhu li forsi tagħmel,
speċjalment jekk inti ħadthom programmati

395
00:18:19,850 --> 00:18:21,390
qabel f'xi lingwa oħra.

396
00:18:21,390 --> 00:18:21,890
Yeah?

397
00:18:21,890 --> 00:18:22,765
>> UDJENZA: [inaudible]

398
00:18:22,765 --> 00:18:25,095

399
00:18:25,095 --> 00:18:25,970
DAVID J. Malan: Yeah.

400
00:18:25,970 --> 00:18:26,470
Eżattament.

401
00:18:26,470 --> 00:18:29,455
Allura dan huwa giving you aċċess għal
librerija, biex ngħidu hekk, ta 'funzjonijiet.

402
00:18:29,455 --> 00:18:31,830
U librerija tal-funzjonijiet hija
funzjonijiet li xi ħadd ieħor

403
00:18:31,830 --> 00:18:34,406
kiteb, jew riċentement
jew twil ilu, sabiex inti

404
00:18:34,406 --> 00:18:35,780
ma jkollhom jivvinta r-rota.

405
00:18:35,780 --> 00:18:39,020
Per eżempju, aħna ma
għandek tkun taf, fl-2015,

406
00:18:39,020 --> 00:18:42,280
kif jiktbu kodiċi li tpoġġi
karattru fuq l-iskrin tiegħi.

407
00:18:42,280 --> 00:18:44,820
Xi ħadd ieħor ħa dehret li
bl-funzjoni printf

408
00:18:44,820 --> 00:18:47,280
sabiex I tista sort ta astratta
bogħod minn dak, jew saff

409
00:18:47,280 --> 00:18:49,350
fuq quċċata ta 'tiegħu jew tagħha
kodiċi, u issa ħu

410
00:18:49,350 --> 00:18:52,760
għall mogħtija li kwalunkwe programm nikteb
jistgħu jistampaw xi ħaġa għall-iskrin.

411
00:18:52,760 --> 00:18:58,150
Allura dan l-ewwel linja hemm fi stadju wieħed
jinkludi l-hekk imsejħa fajl header

412
00:18:58,150 --> 00:18:59,980
għall-librerija standard.

413
00:18:59,980 --> 00:19:02,630
Allura tara, il-lingwa
li aħna issa qed jaħdmu

414
00:19:02,630 --> 00:19:05,010
kellhom librerija standard
ma 'lottijiet ta' funzjonijiet.

415
00:19:05,010 --> 00:19:07,240
Printf huwa wieħed minnhom, u
li l-ewwel linja tal-kodiċi

416
00:19:07,240 --> 00:19:10,040
ifisser jagħtu me aċċess għal
dawk il-funzjonijiet, sabiex I

417
00:19:10,040 --> 00:19:12,300
ma jkollhom jivvinta dik ir-rota.

418
00:19:12,300 --> 00:19:15,940
>> Issa ejja mur l-tieqa qiegħ
u jagħmlu eżattament dak li għamilt qabel.

419
00:19:15,940 --> 00:19:18,520
A mument ilu, meta I kien
whizzing permezz tal-kodiċi,

420
00:19:18,520 --> 00:19:24,540
ittajpjar it out għall-ewwel darba,
I malajr ħafna ittajpjat, jagħmlu bonjour.

421
00:19:24,540 --> 00:19:28,250
Liema kienet li kollha dwar kieku inti raden?

422
00:19:28,250 --> 00:19:29,150
X'kienet I tagħmel?

423
00:19:29,150 --> 00:19:29,649
Yeah?

424
00:19:29,649 --> 00:19:31,810

425
00:19:31,810 --> 00:19:32,310
Qatt f'moħħhom.

426
00:19:32,310 --> 00:19:32,970
Huwa OK.

427
00:19:32,970 --> 00:19:33,492
Yeah.

428
00:19:33,492 --> 00:19:34,450
UDJENZA: Kumpilazzjoni dan.

429
00:19:34,450 --> 00:19:34,700
DAVID J. Malan: Yeah.

430
00:19:34,700 --> 00:19:35,770
Kien biss kompilazzjoni tagħha.

431
00:19:35,770 --> 00:19:36,270
Dritt?

432
00:19:36,270 --> 00:19:39,280
Anke jekk dan huwa kompletament familjari
lilek, huwa pjuttost Ingliż simili.

433
00:19:39,280 --> 00:19:41,155
Huwa ċertament mhux żerijiet
u dawk, so I għadhom

434
00:19:41,155 --> 00:19:44,220
bżonn li run permezz ta 'dak l-hekk imsejħa
programm, kompilatur, li għaddej

435
00:19:44,220 --> 00:19:46,060
li teħodha bħala input u jipproduċu output.

436
00:19:46,060 --> 00:19:48,270
U mill-inqas, għal issa, fil
dan l-ambjent Linux,

437
00:19:48,270 --> 00:19:51,030
iżda dan mhuwiex prerekwiżit,
dan huwa biss fejn aħna ser tibda,

438
00:19:51,030 --> 00:19:53,960
inti ġeneralment jinteraġixxu ma
sistemi tal-kompjuter bħal dan

439
00:19:53,960 --> 00:19:55,770
billi l-hekk imsejħa linja tal-kmand.

440
00:19:55,770 --> 00:19:57,790
Allura ma 'Teptip
pront u t-tastiera tiegħek,

441
00:19:57,790 --> 00:20:01,630
u mhux tant maws, u mhux
hekk twieqi ħafna u ikoni u menus,

442
00:20:01,630 --> 00:20:02,980
pjuttost kollox huwa testwali.

443
00:20:02,980 --> 00:20:06,180
U anki jekk dan iħoss, fl-ewwel
daqqa t'għajn, forsi, bħal pass lura,

444
00:20:06,180 --> 00:20:08,437
huwa attwalment ferm aktar
mod qawwi u ta 'espressjoni

445
00:20:08,437 --> 00:20:10,270
ta tikkontrolla kompjuter
speċjalment kif inti,

446
00:20:10,270 --> 00:20:12,950
yourself, isiru aktar
komdu minn inqas.

447
00:20:12,950 --> 00:20:16,790
Li għaddej biex jippermettu li tagħmel ħafna
affarijiet aktar milli sempliċiment dak Microsoft

448
00:20:16,790 --> 00:20:20,390
jew Apple tippermetti li tagħmel ma '
sistema operattiva grafika tagħhom.

449
00:20:20,390 --> 00:20:23,270
>> Allura meta I hit Ikteb, issa,
xejn jiġri dan iż-żmien

450
00:20:23,270 --> 00:20:25,960
minħabba apparentement l-
bonjour programm tkun aġġornata.

451
00:20:25,960 --> 00:20:28,250
U dak li kien il-kmand
I dam wara li?

452
00:20:28,250 --> 00:20:32,370
Dot mmejla hello, u bonjour dinja.

453
00:20:32,370 --> 00:20:34,350
Issa ejja tagħti pass
lura għal ftit mument.

454
00:20:34,350 --> 00:20:39,510
Jirriżulta li jagħmlu bonjour huwa biss
Mod issimplifikat ta tikkompila programm.

455
00:20:39,510 --> 00:20:41,670
Ejja biss jintroduċu
biċċa waħda ta 'jargon,

456
00:20:41,670 --> 00:20:43,470
iżda mbagħad jimxu bogħod
minnu, peress li huwa ma

457
00:20:43,470 --> 00:20:46,640
dak kollu li interessanti
għal skopijiet lum.

458
00:20:46,640 --> 00:20:51,000
Il kompilatur aħna qed tmur biex tibda tuża
huwa msejjaħ Clang, għall-lingwa C.

459
00:20:51,000 --> 00:20:54,280
U dan huwa programm li s run biss
bħal għamilna fil-linja tal-kmand hemmhekk.

460
00:20:54,280 --> 00:20:56,580
U hekk jekk irrid
jikkompilaw programm li I

461
00:20:56,580 --> 00:21:00,790
kitbu fil-fajl imsejjaħ bonjour dot
c, I litteralment biss tip clang bonjour c

462
00:21:00,790 --> 00:21:02,100
jidħol.

463
00:21:02,100 --> 00:21:04,880
>> Il-ħaġa umoristiċi hija,
għal raġunijiet storiċi,

464
00:21:04,880 --> 00:21:07,750
jekk jien ma jispeċifikawx il-
isem tal-programm

465
00:21:07,750 --> 00:21:11,690
li nixtieq li output, jekk jien ma
tispeċifika isem ta 'fajl għal dawk żerijiet

466
00:21:11,690 --> 00:21:14,990
u dawk, li ħafna stramb
snin konvenzjoni ġiet adottata ilu

467
00:21:14,990 --> 00:21:17,390
fejn jinħass tip ta '
tweġiba tajba fil-ħin,

468
00:21:17,390 --> 00:21:21,650
ukoll ejja biss b'mod arbitrarju sejħa tal-
ewwel programm aħna tikkompila dot out.

469
00:21:21,650 --> 00:21:22,900
A jiġi l-ewwel fl-alfabett.

470
00:21:22,900 --> 00:21:23,920
Out, huwa l-output.

471
00:21:23,920 --> 00:21:26,210
Allura aħna se sejħa tal-programm
awtomatikament dot out.

472
00:21:26,210 --> 00:21:29,550
U li l-multa minħabba li jekk irrid
tmexxi l-programm f'dan it-test ibbażata

473
00:21:29,550 --> 00:21:33,590
ambjent, I biss tip
dot mmejla dot out jidħol.

474
00:21:33,590 --> 00:21:35,250
U imur eżattament bħal qabel.

475
00:21:35,250 --> 00:21:36,880
Mela ejja ara dak reali fast.

476
00:21:36,880 --> 00:21:40,370
>> Mela jekk immur lura għall tiegħi
source code CS50 IDE,

477
00:21:40,370 --> 00:21:47,860
u I minflok tagħmel dan, clang bonjour kerrikot
c jidħlu, avviż xejn ma jidher li jiġri,

478
00:21:47,860 --> 00:21:49,790
iżda kważi dejjem fil
dan l-ambjent Linux,

479
00:21:49,790 --> 00:21:53,310
meta xejn ħażin jidher li jiġri, li
ifisser xi ħaġa tajba fil-fatt ġara.

480
00:21:53,310 --> 00:21:56,270
Jekk ma tarax żball
messaġġ, kollox huwa probabbilment tajjeb.

481
00:21:56,270 --> 00:22:01,930
U fil-fatt, jekk I issa do dot mmejla tikka
out jidħlu, stajt run istess programm tiegħi.

482
00:22:01,930 --> 00:22:04,610
I għad għandhom il-programm bonjour
minn qabel minħabba fil-fatt, huwa

483
00:22:04,610 --> 00:22:07,430
se tkun daqstant nicer biss
tip jagħmel minflok ftakar

484
00:22:07,430 --> 00:22:10,240
dawn incantations ta
kmandi, imma ejja naraw kif nistgħu

485
00:22:10,240 --> 00:22:12,890
jista 'jtejjeb fuq din, madankollu.

486
00:22:12,890 --> 00:22:15,340
>> Allura, dan huwa l-kmand
biex jikkompilaw l-kodiċi.

487
00:22:15,340 --> 00:22:19,100
Dan huwa l-kmand biex imexxu
il-kodiċi ikkumpilata wara.

488
00:22:19,100 --> 00:22:20,546
Kif nista 'tispeċifika isem ta' fajl?

489
00:22:20,546 --> 00:22:22,670
Well ejja biss jintroduċu
wieħed aktar biċċa jargon.

490
00:22:22,670 --> 00:22:24,461
Meta int f'dan
test ambjent ibbażati,

491
00:22:24,461 --> 00:22:27,400
int tmur jridu jispeċifikaw
affarijiet imsejħa argumenti kmand linja.

492
00:22:27,400 --> 00:22:31,380
Li huwa biss mod fancy ta 'tgħid,
kliem ieħor fil-pront li

493
00:22:31,380 --> 00:22:33,860
tweak l-imġiba ta 'kwalunkwe
programm int taħdem.

494
00:22:33,860 --> 00:22:37,320
Allura speċifikament il-programm Jien
tmexxija, billi jiġu ttajpjati l-isem clang,

495
00:22:37,320 --> 00:22:38,504
huwa l-programm imsejjaħ Clang.

496
00:22:38,504 --> 00:22:40,920
Allura dan huwa jew l-iskola antika
ekwivalenti ta 'double-click

497
00:22:40,920 --> 00:22:42,860
fuq Microsoft Word jew
icon xi programm.

498
00:22:42,860 --> 00:22:46,360
Jien minflok sempliċiment ittajpjar isimha,
imma f'dan il-verżjoni tal-kmand,

499
00:22:46,360 --> 00:22:51,334
I mbagħad ikollhom sing spazju o
bonjour ispazju bonjour dot c.

500
00:22:51,334 --> 00:22:53,500
Għalhekk anki jekk inti stajt qatt
lagħbu f'din id-dinja qabel,

501
00:22:53,500 --> 00:22:58,160
ħu raden dak
ma o sing bonjour do?

502
00:22:58,160 --> 00:23:00,620
Jew dak ma tgħid clang tagħmel?

503
00:23:00,620 --> 00:23:01,386
Yeah.

504
00:23:01,386 --> 00:23:02,455
>> UDJENZA: [inaudible]

505
00:23:02,455 --> 00:23:03,330
DAVID J. Malan: Yeah.

506
00:23:03,330 --> 00:23:08,614
Hija biss tistabbilixxi output tal-fajl li jkun
bonjour minflok il-sillier dot out.

507
00:23:08,614 --> 00:23:09,780
U, tabilħaqq, ejja ipprova din.

508
00:23:09,780 --> 00:23:14,250
Mela jekk jien issa do, l-ewwel
ejja tagħmel dan, r m bonjour.

509
00:23:14,250 --> 00:23:15,590
Li jitneħħew.

510
00:23:15,590 --> 00:23:18,450
U li għaddej biex ngħid tneħħi
fajl regolari hello, li

511
00:23:18,450 --> 00:23:22,210
huwa arcane bla bżonn, imma hija biss
mezzi do inti tixtieq li tħassar il-fajl,

512
00:23:22,210 --> 00:23:23,230
u I tip y għall iva.

513
00:23:23,230 --> 00:23:27,340
U avviż, jekk inti kienu glancing fil-quċċata
xellug, hija ma jisparixxu mill up hemm.

514
00:23:27,340 --> 00:23:32,180
Let me issa do o sing clang, u
Jien ser jimxi 'l quddiem u jagħmlu hello,

515
00:23:32,180 --> 00:23:34,890
fil-limiti kollha, bonjour dot c.

516
00:23:34,890 --> 00:23:37,775
Issa, jekk nagħmel dot slash
hello, dak li inti tistenna?

517
00:23:37,775 --> 00:23:41,240

518
00:23:41,240 --> 00:23:42,430
>> Forsi huwa każ sensittivi.

519
00:23:42,430 --> 00:23:43,070
Forsi mhuwiex.

520
00:23:43,070 --> 00:23:44,030
Ejja naraw.

521
00:23:44,030 --> 00:23:45,230
L-ebda fajl jew direttorju.

522
00:23:45,230 --> 00:23:47,438
U nistgħu tip ta iqarrqu bil
biss tħares lejn quċċata xellug.

523
00:23:47,438 --> 00:23:49,630
What did I ovvjament
isalva l-programm kif?

524
00:23:49,630 --> 00:23:51,070
Kollha tappijiet bonjour.

525
00:23:51,070 --> 00:23:53,020
Allura fil-fatt, li għaddej
biex jagħmlu differenza.

526
00:23:53,020 --> 00:23:54,540
Allura issa bonjour dinja huwa lura.

527
00:23:54,540 --> 00:23:56,969
Issa din hija kollha multa u tajjeb,
u kollha ħafna mind numbing-,

528
00:23:56,969 --> 00:23:59,760
li tip ta 'staġnati f'dawn
dettalji, iżda fehim tagħhom

529
00:23:59,760 --> 00:24:00,500
hija tajba.

530
00:24:00,500 --> 00:24:02,675
>> Ittajpjar dawn dejjem
incantations twal

531
00:24:02,675 --> 00:24:05,980
mhux se jkun partikolarment
gost, hekk nies fid-dinja

532
00:24:05,980 --> 00:24:08,260
ivvintat programm ieħor,
xi snin ilu, imsejħa

533
00:24:08,260 --> 00:24:12,190
jagħmlu, li sempliċement
tippermetti li inti tip għamla,

534
00:24:12,190 --> 00:24:14,530
l-isem tal-programm
inti tixtieq li tagħmel, u jagħmlu

535
00:24:14,530 --> 00:24:18,580
huwa intelliġenti fis-sens li għandha tagħti ħarsa fil
l-folder attwali, aka direttorju,

536
00:24:18,580 --> 00:24:21,440
u jekk għandek fajl
imsejħa bonjour dot c,

537
00:24:21,440 --> 00:24:25,800
li huwa l-fajl se tiġbor
għalik fi programm imsejjaħ bonjour.

538
00:24:25,800 --> 00:24:29,950
Allura huwa mod ferm aktar sempliċi ta '
tagħmel l-kmandi aktar cryptic

539
00:24:29,950 --> 00:24:30,800
li għamilna qabel.

540
00:24:30,800 --> 00:24:34,080
U aħna għandna pre-konfigurati
CS50 IDE tkun taf

541
00:24:34,080 --> 00:24:38,560
li għandha tagħmel o sing u numru ta '
bnadar oħra, jew argumenti kmand linja,

542
00:24:38,560 --> 00:24:40,670
li aħna ser tara qabel twil.

543
00:24:40,670 --> 00:24:43,700
>> Imma ejja issa fil-fatt jagħmlu
xi ħaġa aktar interessanti.

544
00:24:43,700 --> 00:24:46,950
Just jittajpja out bonjour dinja kollha
l-ħin huwa mhux kollha li konvinċenti.

545
00:24:46,950 --> 00:24:52,280
So let me jimxi 'l quddiem u l-bidla
dan il-programm u jgħidu, bonjour David.

546
00:24:52,280 --> 00:24:54,120
Issa jien ser jinżlu hawn.

547
00:24:54,120 --> 00:24:57,360
Jien ser jimxi 'l quddiem u jagħmlu jagħmlu bonjour.

548
00:24:57,360 --> 00:25:00,652
U għal darb'oħra issa int tara
tagħmel qed juri inti l-itwal

549
00:25:00,652 --> 00:25:03,360
sekwenza ta 'kmandi li huwa
tagħmel għaliex aħna ħadthom pre-konfigurati

550
00:25:03,360 --> 00:25:05,200
dan il-mod, iżda aħna
bżonn ma tinkwetax għal issa

551
00:25:05,200 --> 00:25:10,735
dak li qed jagħmel ieħor milli huwa
kumpilazzjoni dot mmejla hello, bonjour dinja.

552
00:25:10,735 --> 00:25:14,969

553
00:25:14,969 --> 00:25:15,510
X'hemm ħażin?

554
00:25:15,510 --> 00:25:16,177
Yeah.

555
00:25:16,177 --> 00:25:17,370
>> UDJENZA: [inaudible]

556
00:25:17,370 --> 00:25:18,203
>> DAVID J. Malan: Iva.

557
00:25:18,203 --> 00:25:19,600
Allura, żball noobie.

558
00:25:19,600 --> 00:25:22,394
I Avviż dan huwa super sottili,
iżda l-asterisk hawnhekk, fil-tab,

559
00:25:22,394 --> 00:25:25,060
ifisser biss li inti ma meħlusin,
u browsers u programmi oħra

560
00:25:25,060 --> 00:25:25,930
tagħmel dan kultant.

561
00:25:25,930 --> 00:25:27,939
Allura s kontroll jew kmand
s għandha isalvawh.

562
00:25:27,939 --> 00:25:29,730
Issa let me jimxi 'l quddiem
u terġa 'tmexxi l-programm.

563
00:25:29,730 --> 00:25:33,360

564
00:25:33,360 --> 00:25:34,260
Recompiled.

565
00:25:34,260 --> 00:25:36,050
Dritt, dan huwa proċess multi-pass.

566
00:25:36,050 --> 00:25:39,400
Ebda wieħed minnhom huwa partikolarment kumpless,
iżda kwalunkwe ħin aħna jibdlu l-fajl,

567
00:25:39,400 --> 00:25:43,450
għandna bżonn li tinbidel il-riżultat li
żerijiet u dawk, u dot slash bonjour.

568
00:25:43,450 --> 00:25:43,950
Ara naqra.

569
00:25:43,950 --> 00:25:46,450
Allura dan huwa underwhelming ħafna
li aħna biss stampata dan.

570
00:25:46,450 --> 00:25:48,360
Ejja tagħmel l-affarijiet
ftit aktar dinamiku, issa.

571
00:25:48,360 --> 00:25:52,280
>> Ukoll jirriżulta, li bħal
Scratch, C jappoġġja varjabbli.

572
00:25:52,280 --> 00:25:54,790
U jirriżulta jekk inti tixtieq
li jkollhom varjabbli li l-ħażniet,

573
00:25:54,790 --> 00:25:57,300
mhux numru bħal aħna
tipikament għamlet il Scratch,

574
00:25:57,300 --> 00:26:01,300
iżda bħal kelma, jew
frażi, jew isem, inti

575
00:26:01,300 --> 00:26:04,837
tista 'tispeċifika varjabbli
li jkunu ta 'sekwenza tip.

576
00:26:04,837 --> 00:26:06,670
Allura aħna ser tara aktar ta '
dawn fi ftit mument,

577
00:26:06,670 --> 00:26:09,090
iżda jirriżulta li C, u
ħafna lingwi bhalu,

578
00:26:09,090 --> 00:26:11,240
għandhom tipi speċifiċi ħafna ta 'varjabbli.

579
00:26:11,240 --> 00:26:13,810
Mhuwiex bħad algebra,
fejn ikollok x, y, uz

580
00:26:13,810 --> 00:26:16,940
u dawn huma biss dejjem
numri, b'mod lingwa ta 'programmar

581
00:26:16,940 --> 00:26:20,030
inti jista 'jaħżen numri, inti tista
jaħżnu karattri individwali,

582
00:26:20,030 --> 00:26:24,619
inti tista 'taħżen kelma sħaħ, inti tista
jaħżnu ritratti kollha, fajls sħaħ ħoss,

583
00:26:24,619 --> 00:26:25,160
u simili.

584
00:26:25,160 --> 00:26:28,362
Għalhekk għandna bżonn li jispeċifikaw liema
it-tip ta 'varjabbli tagħna huwa.

585
00:26:28,362 --> 00:26:31,570
U mill-konvenzjoni jien ser sejħa tiegħi
s varjabbli biss għaliex dan huwa konċiż,

586
00:26:31,570 --> 00:26:33,510
u s stands għall sekwenza.

587
00:26:33,510 --> 00:26:36,400
>> U allura jien ser taħżen
ġewwa ta 'dan il-varjabbli,

588
00:26:36,400 --> 00:26:39,570
Eżatt bħal ma Scratch
meta nuża l-blokk stabbilit,

589
00:26:39,570 --> 00:26:41,950
Jien ser tuża l-
operatur assignment fis C,

590
00:26:41,950 --> 00:26:45,290
li nicely biżżejjed huwa l-istess
tiffirma, imma s-sinjal ugwali ma dan.

591
00:26:45,290 --> 00:26:53,220
Jiċċaqlaq xi ħaġa fuq il-lemin fil
in-naħa tax-xellug tal-espressjoni.

592
00:26:53,220 --> 00:26:57,170
Allura dak I għamlu, li jkun ċar fil
linja ħames, hija stajt ddikjarat varjabbli.

593
00:26:57,170 --> 00:27:01,284
Stajt qal lill-kompjuter, jagħtu me
memorja għal varjabbli, sejħa hija s-

594
00:27:01,284 --> 00:27:03,950
u jaf minn qabel li jien ser
li tkun tqegħid string fiha.

595
00:27:03,950 --> 00:27:05,950
U string huwa biss
sekwenza ta 'karattri.

596
00:27:05,950 --> 00:27:09,190
Huwa kelma, jew frażi, jew il-paragrafu,
imma hija sekwenza ta 'karattri.

597
00:27:09,190 --> 00:27:10,610
Mhuwiex numri.

598
00:27:10,610 --> 00:27:13,800
What string am I se tkun
tqegħid fis dak il-varjabbli?

599
00:27:13,800 --> 00:27:16,185
Well, apparentement nikkwota
unquote, "Hannah".

600
00:27:16,185 --> 00:27:17,810
Issa avviż l-mudell li l-emerġenti.

601
00:27:17,810 --> 00:27:19,260
Hemm espressjoni naħa tax-xellug.

602
00:27:19,260 --> 00:27:21,810
Hemm espressjoni lemin,
sseparati bil-sinjal ugwali.

603
00:27:21,810 --> 00:27:24,390
U ħu raden, jekk
familjari madankollu,

604
00:27:24,390 --> 00:27:27,430
ma 'dak il-virgola qed tagħmel.

605
00:27:27,430 --> 00:27:28,865
X'hemm dan preżumibbilment tagħmel għalina?

606
00:27:28,865 --> 00:27:29,365
Yeah?

607
00:27:29,365 --> 00:27:29,840
>> UDJENZA: [inaudible]

608
00:27:29,840 --> 00:27:29,980
>> DAVID J. Malan: Yeah.

609
00:27:29,980 --> 00:27:31,170
Huwa biss li jtemm il-linja.

610
00:27:31,170 --> 00:27:31,669
Dritt?

611
00:27:31,669 --> 00:27:34,260
Il-kompjuters tixtieq li tkun bi frankezza
jafu, litteralment, x'għandek tagħmel.

612
00:27:34,260 --> 00:27:36,343
Bħall-butir tal-karawett u
eżempju sandwich jelly,

613
00:27:36,343 --> 00:27:39,360
jekk inti ma jispeċifikawx
eżattament dak li għandek il-ħsieb,

614
00:27:39,360 --> 00:27:42,190
jista 'jitħalla għas-sentenza jew żball.

615
00:27:42,190 --> 00:27:44,890
Il virgola ifisser,
din hija għal dan il-kmand.

616
00:27:44,890 --> 00:27:48,310
Huwa qed super preċiżi, u huwa
ħaġa faċli ħafna li jħallu off.

617
00:27:48,310 --> 00:27:52,240
Allura issa dan il-programm ma jidhirx li
jiġu iġib ruħu b'mod differenti sakemm I

618
00:27:52,240 --> 00:27:53,500
jagħmilha aktar dinamiku.

619
00:27:53,500 --> 00:27:57,107
Allura minflok hard jista tiegħi stess
isem, let me tpoġġi valur placeholder.

620
00:27:57,107 --> 00:28:00,190
U jirriżulta li, u naf dan
meta tkun aqra d-dokumentazzjoni,

621
00:28:00,190 --> 00:28:04,080
u uża l-funzjoni għas-snin, li
printf kienet maħsuba biex tkun dinamika.

622
00:28:04,080 --> 00:28:07,510
Inti ma għandekx tkun taf minn qabel
liema kliem inti tixtieq li tqiegħed fiha.

623
00:28:07,510 --> 00:28:11,290
Tista 'minflok' jkollhom
placeholder, bħal fil-mija s, li

624
00:28:11,290 --> 00:28:15,500
se tgħid il-
kompjuter, poġġi string hawn.

625
00:28:15,500 --> 00:28:17,740
>> Li string irridu li tqiegħed hemmhekk?

626
00:28:17,740 --> 00:28:22,430
Will jirriżulta li bejn dawn
parentesi, li tiftakar, jiddemarkaw

627
00:28:22,430 --> 00:28:28,020
l-input għal funzjoni, jekk għandek
comma separati lista ta 'affarijiet hawn,

628
00:28:28,020 --> 00:28:31,790
aħna fil-fatt jgħaddu fil multipli
inputs għal funzjoni.

629
00:28:31,790 --> 00:28:33,901
Hekk biss bħal xi Scratch
blokki, inti tista 'ma

630
00:28:33,901 --> 00:28:36,150
kellhom magħhom għal
proġetti tiegħek għadhom jew fil kollha,

631
00:28:36,150 --> 00:28:38,250
xi blokki Scratch għandhom żewġ inputs.

632
00:28:38,250 --> 00:28:41,220
Żewġ kaxxi bojod inti tista
tip numri jew kliem fis.

633
00:28:41,220 --> 00:28:45,210
Allura biex ma C jkollhom funzjonijiet simili
printf li tista 'tieħu żewġ inputs.

634
00:28:45,210 --> 00:28:48,050
U għal darb'oħra, dan comma
huwa tisseparahom.

635
00:28:48,050 --> 00:28:51,070
Allura bl-Ingliż, għal darb'oħra anki jekk
inti stajt qatt programmati qabel,

636
00:28:51,070 --> 00:28:55,320
billi dan printf loġika hija funzjoni,
jieħu żewġ inputs, li waħda minnhom

637
00:28:55,320 --> 00:28:58,810
huwa placeholder, dak li inti t-tama
printf se tagħmel ma 'dan il-kontribut?

638
00:28:58,810 --> 00:29:01,470

639
00:29:01,470 --> 00:29:03,220
Li għaddej biex jgħidu bonjour
Hannah, nisperaw.

640
00:29:03,220 --> 00:29:05,274
Allura biex tagħmel dan għandna bżonn biex isalvawh.

641
00:29:05,274 --> 00:29:06,190
Jien ser zoom out.

642
00:29:06,190 --> 00:29:10,701
Jien se jmorru lura hawn
u jgħidu, jagħmlu bonjour jidħlu.

643
00:29:10,701 --> 00:29:11,200
Oh.

644
00:29:11,200 --> 00:29:14,830
Xi ħaġa ħażin, u fil-fatt
dan huwa pjuttost kbira.

645
00:29:14,830 --> 00:29:18,400
I ikollhom sitt linji ta 'kodiċi
u bħall 12 linji ta 'żbalji.

646
00:29:18,400 --> 00:29:22,120
Allura, bil-ħerqa għal dan.

647
00:29:22,120 --> 00:29:24,260
Allura x'inhu għaddej hawn?

648
00:29:24,260 --> 00:29:27,370
Allura l-aħjar regola ġenerali hawn,
speċjalment meta int bdew,

649
00:29:27,370 --> 00:29:29,370
ma jsibux distracted mill
l-għalf fil-qiegħ.

650
00:29:29,370 --> 00:29:31,220
Fil-fatt, I ħafna deliberatament
biss impress up

651
00:29:31,220 --> 00:29:33,930
għaliex ħafna drabi, kompjuter huwa
mhux kollha li bright ta 'apparat.

652
00:29:33,930 --> 00:29:35,054
Huwa ser titħawwad.

653
00:29:35,054 --> 00:29:37,220
Jekk jidhrilha ħaġa waħda li
ma tifhimx,

654
00:29:37,220 --> 00:29:40,030
dan jista 'jfixkilhom oħra
linji ta 'kodiċi bħala mhux korretti,

655
00:29:40,030 --> 00:29:41,649
anki jekk dawn qed perfettament multa.

656
00:29:41,649 --> 00:29:43,940
Allura inti dejjem tixtieq taħdem
top stabbiliti permezz tal-iżbalji.

657
00:29:43,940 --> 00:29:47,850
U ċertament din hija
super arcane fil-mument.

658
00:29:47,850 --> 00:29:50,830
>> Error, l-użu ta 'mhux iddikjarat
string identifikatur.

659
00:29:50,830 --> 00:29:52,130
Did I tfisser standard fil-?

660
00:29:52,130 --> 00:29:53,720
Le, I fisser string.

661
00:29:53,720 --> 00:29:55,830
U huwa tipponta lejn, forsi huwa typo.

662
00:29:55,830 --> 00:30:00,570
Tip simili, fil-verifika jespliċitaw-
mod geeky ħafna, iżda r-raġuni hawnhekk,

663
00:30:00,570 --> 00:30:02,840
u tkun taf taf dan
biss mill-prattika, huwa

664
00:30:02,840 --> 00:30:06,390
li jirriżulta li string
ma jeżistix fil C. Fil-fatt, C

665
00:30:06,390 --> 00:30:08,820
hija lingwa partikolarment qodma,
u huwa livell baxx ħafna,

666
00:30:08,820 --> 00:30:11,361
U ma ħafna karatteristiċi
li jista 'jkollok kibru

667
00:30:11,361 --> 00:30:14,620
ma jekk għandek, fil-fatt, programmati
fl Java, kif xi wħud minnkom,

668
00:30:14,620 --> 00:30:16,980
imma int tista jgħallmu affarijiet ġodda.

669
00:30:16,980 --> 00:30:20,900
U fil-fatt, għamilna dan CS50,
anki jekk sa l-aħħar tas-semestru,

670
00:30:20,900 --> 00:30:23,512
kollha ta 'dawn ir-roti ta' taħriġ
se tneħħew mis-

671
00:30:23,512 --> 00:30:25,220
dak li nagħmlu f'dawn
ewwel ftit ġimgħat

672
00:30:25,220 --> 00:30:29,830
inizjalment huwa irridu wkoll
inti jinkludu CS50 dot h.

673
00:30:29,830 --> 00:30:31,230
Li huwa fajl header.

674
00:30:31,230 --> 00:30:32,440
Aktar dwar dan fil-futur.

675
00:30:32,440 --> 00:30:36,430
>> Huwa fajl li fih funzjonijiet
li għandna bil-miktub għalik.

676
00:30:36,430 --> 00:30:39,180
U fost dawk il-funzjonijiet huwa
funzjonijiet biex jinkiseb input

677
00:30:39,180 --> 00:30:43,520
mill-utent, bħall kordi, u
numri, u n-numri reali, u aktar.

678
00:30:43,520 --> 00:30:45,550
Iżda għandu wkoll xi shortcuts ftit.

679
00:30:45,550 --> 00:30:48,200
Din tiddefinixxi Boolean bħala tip ta 'data.

680
00:30:48,200 --> 00:30:50,340
C ma jkollux vera jew falza.

681
00:30:50,340 --> 00:30:53,880
Iżda aħna tista 'tagħtiha l-kunċett ta'
vera jew falza permezz ta 'din il-librerija.

682
00:30:53,880 --> 00:30:57,670
U lanqas ma jkollu string
mibnija sakemm aħna jinkludu din il-linja.

683
00:30:57,670 --> 00:31:01,090
Allura din il-linja tal-kodiċi jgħidlekx
l-kumpilatur, ħej, Clang, tfittex

684
00:31:01,090 --> 00:31:03,570
f'dan il-fajl għal kollu
mazz ta 'kodiċi li CS50

685
00:31:03,570 --> 00:31:06,330
kitbet sabiex
kull min juża dan il-fajl

686
00:31:06,330 --> 00:31:09,330
tista 'tieħu għall mogħtija l-
Karatteristiċi li ħadthom miżjud.

687
00:31:09,330 --> 00:31:11,220
>> Allura issa let me jimxi 'l quddiem
u ċar l-iskrin,

688
00:31:11,220 --> 00:31:14,178
u jekk kurjużi jien biss qal kontroll
l kull darba biex ċar l-iskrin,

689
00:31:14,178 --> 00:31:15,500
jew inti tista tip ċara.

690
00:31:15,500 --> 00:31:19,220
Jien biss se jimxi 'l quddiem issa u
tip jagħmel hello, u kollox huwa tajjeb.

691
00:31:19,220 --> 00:31:22,550
Still produzzjoni arcane, iżda
mhuwiex messaġġ żbaljat.

692
00:31:22,550 --> 00:31:28,300
Issa jekk nagħmel dot mmejla hello, u bħala
aside, dot slash huwa familjari għal ħafna.

693
00:31:28,300 --> 00:31:30,430
Dan ifisser biss, dot mezzi
l-direttorju kurrenti.

694
00:31:30,430 --> 00:31:33,120
Mela jekk inti stajt qatt jintużaw
DOS, jew Linux, Unix jew

695
00:31:33,120 --> 00:31:35,410
inti tista għamlu xi ħaġa
bħal cd dot dot, fejn

696
00:31:35,410 --> 00:31:39,220
dot dot ifisser jmorru lura fil
time, jew mur lura, jew ogħla sa

697
00:31:39,220 --> 00:31:40,370
direttorju tiegħek.

698
00:31:40,370 --> 00:31:43,090
Dot ifisser biss ħarsa fil
l-direttorju kurrenti.

699
00:31:43,090 --> 00:31:45,670
Irrid hello, li huwa dritt hawn.

700
00:31:45,670 --> 00:31:47,750
U fil-fatt, issa jgħid bonjour Hannah.

701
00:31:47,750 --> 00:31:51,120
U jekk nibdel mill-ġdid
li Maria, recompile

702
00:31:51,120 --> 00:31:55,650
ikun jagħmel hello, dot slash
hello, il-programm jżomm jinbidlu.

703
00:31:55,650 --> 00:31:58,060
>> Iżda dan għadu
programm pretty stupid.

704
00:31:58,060 --> 00:32:00,972
Jekk irrid li vapur dan il-programm,
jew jagħtu lil habib,

705
00:32:00,972 --> 00:32:03,430
jew jagħtu lill Maria jew Hannah
għal dik il-kwistjoni, li l-multa.

706
00:32:03,430 --> 00:32:07,300
I tista customize għal tnejn minnhom,
iżda huwa qatt ser tkun dinamika.

707
00:32:07,300 --> 00:32:10,870
Huma ma jistgħux jibdlu darba huwa kkompilat
isfel lejn dawk żerijiet u dawk.

708
00:32:10,870 --> 00:32:12,350
Allura dak li għamilna xi ħaġa aktar intelliġenti?

709
00:32:12,350 --> 00:32:17,100
X'jiġri jekk, minflok hard-kodifikazzjoni
fil-programm isem din il-persuna,

710
00:32:17,100 --> 00:32:20,890
dak jekk aħna biss jiksbu
il-sekwenza fuq talba?

711
00:32:20,890 --> 00:32:22,430
>> Allura fi kliem ieħor, let me tagħmel dan.

712
00:32:22,430 --> 00:32:24,030
Jien ser recompile dan il-programm.

713
00:32:24,030 --> 00:32:25,710
U let me zoom fil-qiegħ issa.

714
00:32:25,710 --> 00:32:29,920
Jagħmlu bonjour dot slash bonjour.

715
00:32:29,920 --> 00:32:31,710
Issa xejn qed jiġri.

716
00:32:31,710 --> 00:32:35,860
Nistgħu jiksbu voluntier malajr
biex jagħmlu xi ħaġa jiġri?

717
00:32:35,860 --> 00:32:36,360
Come fuq up.

718
00:32:36,360 --> 00:32:37,020
X'hemm isem tiegħek?

719
00:32:37,020 --> 00:32:37,445
>> Pancho: Pancho.

720
00:32:37,445 --> 00:32:38,361
>> DAVID J. Malan: Pacho?

721
00:32:38,361 --> 00:32:39,609
Come fuq up.

722
00:32:39,609 --> 00:32:42,150
Ladarba inti tikseb up hawn, dan huwa
se tkun underwhelming ħafna,

723
00:32:42,150 --> 00:32:44,060
iżda huwa aktar interessanti
minn lili ittajpjar dan.

724
00:32:44,060 --> 00:32:49,007
Jekk inti tixtieq li tmur quddiem u t-tip tiegħek
isem, I magħmula dan il-programm biss ghalik.

725
00:32:49,007 --> 00:32:49,840
Just tip ismek.

726
00:32:49,840 --> 00:32:52,380

727
00:32:52,380 --> 00:32:53,900
Ikteb.

728
00:32:53,900 --> 00:32:54,489
Wonderful.

729
00:32:54,489 --> 00:32:55,780
Kull dritt, nirringrazzjak ħafna.

730
00:32:55,780 --> 00:32:56,708
>> Pancho: Grazzi ħafna.

731
00:32:56,708 --> 00:32:57,636
>> DAVID J. Malan: OK.

732
00:32:57,636 --> 00:32:59,028
>> [Applause]

733
00:32:59,028 --> 00:33:00,884

734
00:33:00,884 --> 00:33:01,840
>> Dan kien ħafna tip.

735
00:33:01,840 --> 00:33:03,145
Hawnhekk inti tmur.

736
00:33:03,145 --> 00:33:03,770
What did nagħmlu?

737
00:33:03,770 --> 00:33:05,930
Allura aħna finalment, għall-inqas,
magħmula dan il-programm dinamiku.

738
00:33:05,930 --> 00:33:08,400
Issa huwa għadu ċertament
billi underwhelming disinn,

739
00:33:08,400 --> 00:33:11,480
iżda aħna finalment ikollhom l-abbiltà
issa biex jikteb il-kodiċi bil-quddiem, ħafna

740
00:33:11,480 --> 00:33:13,770
bħall-awturi ta 'printf,
u mbagħad dinamiku

741
00:33:13,770 --> 00:33:17,550
jadattaw ibbażata fuq il-kontribut aħna
mogħtija, jew mill-programmer,

742
00:33:17,550 --> 00:33:20,610
jew mill-bniedem li attwalment
interazzjoni mal-programm.

743
00:33:20,610 --> 00:33:22,990
Mela ejja fil-fatt issa tipprova
li do a constructs oħra ftit

744
00:33:22,990 --> 00:33:26,625
u ara jekk aħna ma tistax tagħmel il-programmi
lilhom infushom b'mod aktar sofistikati.

745
00:33:26,625 --> 00:33:29,250
Mela ejja imorru quddiem u minflok
miktub dan wieħed mill-bidunett,

746
00:33:29,250 --> 00:33:31,540
Jien se jmorru fil-lum
source code, u dan kollu

747
00:33:31,540 --> 00:33:34,290
hija disponibbli fuq li l-kors
website, u inti tista 'ttawwal u qatra

748
00:33:34,290 --> 00:33:36,590
fl-ambjent tiegħek stess
come il-ġimgħa ladarba problema

749
00:33:36,590 --> 00:33:38,506
sett 1 jagħtik l-
istruzzjonijiet, jew inti tista '

750
00:33:38,506 --> 00:33:41,200
jagħmlu dan fil-linja tal-kmand bħala
ukoll, iżda aktar li ġejjin fil-p stabbilixxa l-1.

751
00:33:41,200 --> 00:33:44,940
>> Ejja naraw x'hemm f'dan il-programm
hawn imsejħa, aġent li jżid dot c.

752
00:33:44,940 --> 00:33:47,970
Issa stajt diġà kkummentaw
dan, imma x'hemm ġdid?

753
00:33:47,970 --> 00:33:51,230
Ewwel daqqa t'għajn, liema linja
tal-kodiċi huwa assolutament ġdida?

754
00:33:51,230 --> 00:33:53,930

755
00:33:53,930 --> 00:33:56,780
Probabbilment le fundamentalment
familjari issa.

756
00:33:56,780 --> 00:33:58,417
>> UDJENZA: [inaudible]

757
00:33:58,417 --> 00:34:00,250
DAVID J. Malan: Yeah,
hekk int x ugwali tikseb n.

758
00:34:00,250 --> 00:34:03,760
Imxejna qatt xi parti minn din
qabel, iżda int huwa probabbilment

759
00:34:03,760 --> 00:34:08,179
is-simbolu għal liema tip ta '
varjabbli, [? minn?] integer.

760
00:34:08,179 --> 00:34:09,040
Allura int għal numru sħiħ.

761
00:34:09,040 --> 00:34:11,420
Huwa biss qed aktar
konċiż. x hija biss arbitrarju.

762
00:34:11,420 --> 00:34:13,920
x uy u z għadhom
pretty raġonevoli għal numri,

763
00:34:13,920 --> 00:34:16,790
iżda ġeneralment aħna ser jużaw kliem darba
programmi tagħna jiksbu aktar kumplessi.

764
00:34:16,790 --> 00:34:18,940
Get int, naturalment,
ferm simili get spag,

765
00:34:18,940 --> 00:34:21,629
huwa probabbilment se tikseb
l int mill-utent,

766
00:34:21,629 --> 00:34:23,670
u allura aħna qed tmur biex
jagħmlu l-istess ħaġa ma 'y.

767
00:34:23,670 --> 00:34:27,610
U apparentement, anke jekk din
aħħar linja, 24, jistenna aktar kumplessi,

768
00:34:27,610 --> 00:34:32,679
li għaddej biex ngħid is-somma ta 'dan
u li huwa dan ħaġa oħra.

769
00:34:32,679 --> 00:34:35,840
>> Ui avviż fil-mija
probabbilment tindika liema?

770
00:34:35,840 --> 00:34:38,190
X'rwol mija
i apparentement sservi?

771
00:34:38,190 --> 00:34:40,739

772
00:34:40,739 --> 00:34:41,719
Huwa biss placeholders.

773
00:34:41,719 --> 00:34:42,219
Dritt?

774
00:34:42,219 --> 00:34:45,149
Mija s kien għal string,
mija i huwa għall integer.

775
00:34:45,149 --> 00:34:47,690
Hemm għaddej li jkun fil-mija f
għall floating punt valur, li

776
00:34:47,690 --> 00:34:49,273
huwa biss numru bi punt deċimali.

777
00:34:49,273 --> 00:34:50,590
Fi kliem ieħor, numru reali.

778
00:34:50,590 --> 00:34:55,270
Mela ejja fil-fatt jiġbor dan
programm reali fast u ma tagħmel aġent li jżid.

779
00:34:55,270 --> 00:34:57,962
Whoops.

780
00:34:57,962 --> 00:34:58,670
Opportunità tajba.

781
00:34:58,670 --> 00:35:02,970
Allura avviż hawn, dan il-ħin l-utent tiegħi
isem għal dan il-kont huwa jharvard.

782
00:35:02,970 --> 00:35:06,620
I am fil IDE CS50, aka IDE50.

783
00:35:06,620 --> 00:35:11,030
U issa bil-blu hawnhekk, huwa jsemmi, iżda
mill-ambjent, ta 'fejn I am.

784
00:35:11,030 --> 00:35:16,050
U fil-fatt, jekk I zoom sal-quċċata
hawn, avviż li għandi IDE50

785
00:35:16,050 --> 00:35:19,490
u nara din il-kelma, jekk inti tip ta '
dawran ras tiegħek għall-ġenb, workspace.

786
00:35:19,490 --> 00:35:23,890
Fil-qosor, il-fatt li
Jien jaraw workspace slash tilde

787
00:35:23,890 --> 00:35:26,910
ifisser li f'dan it-test
ibbażata ambjent kmand,

788
00:35:26,910 --> 00:35:32,300
I am fl-ekwivalenti test ta
dan grafiċi folder up here.

789
00:35:32,300 --> 00:35:35,730
Allura meta I do dot slash
aġent li jżid, huwa qal ebda regola

790
00:35:35,730 --> 00:35:37,372
li jagħmlu waqfa aġent li jżid mira.

791
00:35:37,372 --> 00:35:39,830
I do not know dak li tfisser,
iżda huwa ħażin għal xi raġuni.

792
00:35:39,830 --> 00:35:43,310
L-ebda fajl jew direttorju
huwa saħansitra aktar ċar.

793
00:35:43,310 --> 00:35:45,670
Fejn huwa mbagħad?

794
00:35:45,670 --> 00:35:47,820
Ibbażat fuq fejn I għafast
li tiftaħ il-fajl preċedenti.

795
00:35:47,820 --> 00:35:49,442
Fejn jista 'jkun?

796
00:35:49,442 --> 00:35:52,050
>> Huwa probabbilment fis-sors ta
w wieħed, għal l-Erbgħa,

797
00:35:52,050 --> 00:35:53,960
u I tista 'tara, tabilħaqq,
jekk I miftuħa li sa.

798
00:35:53,960 --> 00:35:57,220
Hemm aġent li jżid dot c, iżda fil
dan l-ambjent ibbażat fuq test,

799
00:35:57,220 --> 00:35:59,380
għal darb'oħra, I għandhom ikunu super espliċita.

800
00:35:59,380 --> 00:36:03,950
Jekk I trid tibdel direttorji fis
sors wieħed Erbgħa I bżonn għat-tip,

801
00:36:03,950 --> 00:36:07,210
cd ispazju sors wieħed
L-Erbgħa jidħlu u issa

802
00:36:07,210 --> 00:36:09,810
bidliet fil-pront tiegħi għal
tagħti me a CUÉ viżwali li

803
00:36:09,810 --> 00:36:12,330
Jien, tabilħaqq, x'imkien ieħor
fl-ambjent tiegħi,

804
00:36:12,330 --> 00:36:15,710
imma issa I jistgħu do jagħmlu
aġent li jżid, jidher li jaħdem,

805
00:36:15,710 --> 00:36:18,190
dot mmejla aġent li jżid, tagħti me numru sħiħ.

806
00:36:18,190 --> 00:36:19,080
One.

807
00:36:19,080 --> 00:36:20,070
Tnejn.

808
00:36:20,070 --> 00:36:21,630
Is-somma ta 'wieħed u tnejn huwa tlieta.

809
00:36:21,630 --> 00:36:24,140
Imma jekk jien ma tikkooperax,
ejja ara dak tikseb int ma.

810
00:36:24,140 --> 00:36:25,200
Agħti me integer.

811
00:36:25,200 --> 00:36:26,590
No

812
00:36:26,590 --> 00:36:27,350
Retry.

813
00:36:27,350 --> 00:36:29,060
OK.

814
00:36:29,060 --> 00:36:30,520
Multa.

815
00:36:30,520 --> 00:36:32,130
50.

816
00:36:32,130 --> 00:36:32,680
50.

817
00:36:32,680 --> 00:36:33,010
Kull dritt.

818
00:36:33,010 --> 00:36:34,055
Allura finalment tikkoopera.

819
00:36:34,055 --> 00:36:36,430
U li wħud mill-
funzjonalità li dawn il-funzjonijiet

820
00:36:36,430 --> 00:36:37,760
jistgħu jkunu mibnija għalik.

821
00:36:37,760 --> 00:36:43,330
>> Allura ġewwa l-implimentazzjoni
tal nikseb int, dak li l-ipprogrammar

822
00:36:43,330 --> 00:36:47,990
jinbena mill-aħħar ġimgħa hija probabbilment fl
hemm biex iġġiegħel din l-imġiba ta 'retry,

823
00:36:47,990 --> 00:36:49,962
retry, retry?

824
00:36:49,962 --> 00:36:51,670
Yeah, hemm probabilment
xi tip ta 'loop.

825
00:36:51,670 --> 00:36:54,160
Li għaddej biex tfittex sintattikament
differenti minn blokok Scratch, il

826
00:36:54,160 --> 00:36:55,880
iżda li fil-fatt
x'hemm ġewwa l-fajl.

827
00:36:55,880 --> 00:36:58,505
U fi żmien ftit ġimgħat aħna ser
fil-fatt tfittex fil-librerija CS50

828
00:36:58,505 --> 00:37:02,000
dwar x'hemm ġewwa, iżda hemm
a loop timponi eżattament dan.

829
00:37:02,000 --> 00:37:04,840
>> Ejja play ftit iblah
logħba hawn ma 'dan il-fajl.

830
00:37:04,840 --> 00:37:06,550
Kundizzjoni żero dot c.

831
00:37:06,550 --> 00:37:08,960
Aħna biss se ġeneralment
jibdew jingħaddu għal żero.

832
00:37:08,960 --> 00:37:11,220
U I iżommu scrolling passat
xi wħud mill-għalf fil-quċċata.

833
00:37:11,220 --> 00:37:15,390
Bil-blu hawn, demarkata kollha
ta 'dawn l-istilel u l-slashes,

834
00:37:15,390 --> 00:37:17,310
dawk minnkom li programm
qabel, dak li huwa dan?

835
00:37:17,310 --> 00:37:18,690
Għaliex inżommu taqbeż is-site fuqha?

836
00:37:18,690 --> 00:37:19,110
What?

837
00:37:19,110 --> 00:37:19,490
>> UDJENZA: Huwa kumment.

838
00:37:19,490 --> 00:37:19,800
>> DAVID J. Malan: Yeah.

839
00:37:19,800 --> 00:37:20,633
Huwa biss kumment.

840
00:37:20,633 --> 00:37:24,160
Dan huwa kumment għall-bnedmin
biex jinqraw, li fil-każ tagħna,

841
00:37:24,160 --> 00:37:27,120
tgħidilna dak li l-isem tal-fajl
huwa, li kiteb dan, u dak li ma,

842
00:37:27,120 --> 00:37:28,610
sabiex inti ma għandekx
biex tinqara permezz-kodiċi

843
00:37:28,610 --> 00:37:30,110
li tkun taf liema dan il-fajl huwa kollha madwar.

844
00:37:30,110 --> 00:37:33,110
Huwa biss deskrizzjoni, imma
funzjonalment huwa irrilevanti.

845
00:37:33,110 --> 00:37:35,930
U nista 'anki titħassar mill
fajl tiegħi u ma jkollu ebda impatt.

846
00:37:35,930 --> 00:37:38,740
Il-linji mmerraq huma dawn
ewwel tnejn hawn, issa.

847
00:37:38,740 --> 00:37:41,405
null prinċipali int huwa l-ekwivalenti
minn meta tagħna bandiera aħdar għafast,

848
00:37:41,405 --> 00:37:44,030
hekk aħna qed tmur biex jitlaq minn dak tkun
għal-lum, u aħna ser terga 'lura,

849
00:37:44,030 --> 00:37:46,940
eventwalment, dwar liema
int u mingħajr effett huma, iżda issa,

850
00:37:46,940 --> 00:37:49,500
Avviż dak I ghamilt
Hawnhekk ukoll, inti tista 'wkoll,

851
00:37:49,500 --> 00:37:51,736
jekk għandek konformi
jikkummentaw, jekk għandek

852
00:37:51,736 --> 00:37:54,670
a ħsibt inti tixtieq li jaqsmu
dwar linja partikolari ta 'kodiċi,

853
00:37:54,670 --> 00:37:58,910
konvenzjoni C huwa li tagħmel mmejla
slash, u kliem konċiż mbagħad ftit,

854
00:37:58,910 --> 00:38:01,500
mhix sentenza sħiħa,
ġeneralment mhux paragrafu,

855
00:38:01,500 --> 00:38:05,310
li biss jispjega lilek, jew tiegħek
TF, jew qarrejja jew kollegi oħra,

856
00:38:05,310 --> 00:38:06,990
dak kodiċi tiegħek qed tagħmel.

857
00:38:06,990 --> 00:38:10,150
Allura minflok li tħares
f'dan u jiddeduċu minn linji

858
00:38:10,150 --> 00:38:12,550
disa u 10, dak li huwa
dan isir, b'konformità tmienja

859
00:38:12,550 --> 00:38:14,945
I biss jagħtu kumment li
issaqsi lill-utent biex integer,

860
00:38:14,945 --> 00:38:17,820
allura jien ma jkollhom biex jaħsbu wisq iebes
dwar dak Linji disa u 10.

861
00:38:17,820 --> 00:38:19,720
I biss jafu li dan huwa dak
kollettivament li qed isir.

862
00:38:19,720 --> 00:38:20,460
>> Kif?

863
00:38:20,460 --> 00:38:22,060
Well, hawn l--pront.

864
00:38:22,060 --> 00:38:23,610
Hawn il-jkollna tal-int.

865
00:38:23,610 --> 00:38:25,984
U bbażati fuq il-preċedenti
imġieba, jidher li huwa simili get int

866
00:38:25,984 --> 00:38:29,080
huwa intelliġenti biżżejjed li jiġi żgurat li
il-bniedem jikkoopera u jagħtiha

867
00:38:29,080 --> 00:38:30,090
integer.

868
00:38:30,090 --> 00:38:32,270
Imma issa naraw dan.

869
00:38:32,270 --> 00:38:33,740
U dan huwa reminixxenti tal scratch.

870
00:38:33,740 --> 00:38:36,140
Jien fejn sostniet li jien
analiżi tal-input tal-utent,

871
00:38:36,140 --> 00:38:39,050
iżda kemmxejn impreċiż.

872
00:38:39,050 --> 00:38:43,200
U dan apparentament C hija kif
aħna jesprimu jekk inkella, fergħa,

873
00:38:43,200 --> 00:38:46,320
furketta fit-triq, imma I
jgħidu kemmxejn impreċiż.

874
00:38:46,320 --> 00:38:50,470
X'inhu l-bug f'dan il-programm?

875
00:38:50,470 --> 00:38:51,610
About aktar lura?

876
00:38:51,610 --> 00:38:52,223
Yeah.

877
00:38:52,223 --> 00:38:53,150
>> UDJENZA: [inaudible] żero.

878
00:38:53,150 --> 00:38:54,025
>> DAVID J. Malan: Yeah.

879
00:38:54,025 --> 00:38:57,630
Mela jekk jien tip fil żero, ejja jikkunsidraw
eżattament il-każ każ, jew rokna,

880
00:38:57,630 --> 00:38:58,450
jekk inti se.

881
00:38:58,450 --> 00:39:02,790
Mela jekk jien tip fil żero, liema minn
blokki se apparentement grab?

882
00:39:02,790 --> 00:39:04,660
Il jekk jew il-inkella?

883
00:39:04,660 --> 00:39:07,340
Il inkella, u li għaddej biex ngħid,
inti qabad numru negattiv.

884
00:39:07,340 --> 00:39:10,476
U fil-fatt, żero mhux suppost
li jkun pożittiv jew negattiv,

885
00:39:10,476 --> 00:39:11,850
u għalhekk li jkun żbaljat.

886
00:39:11,850 --> 00:39:12,930
Dan ikun bug.

887
00:39:12,930 --> 00:39:14,580
Allura kif nistgħu jiffissaw dan?

888
00:39:14,580 --> 00:39:16,360
Xi ħadd li qatt programmati qabel?

889
00:39:16,360 --> 00:39:16,570
Do inti want--

890
00:39:16,570 --> 00:39:17,480
>> UDJENZA: [inaudible]

891
00:39:17,480 --> 00:39:17,990
>> DAVID J. Malan: tiġbed lura?

892
00:39:17,990 --> 00:39:18,570
>> UDJENZA: [inaudible]

893
00:39:18,570 --> 00:39:18,930
>> DAVID J. Malan: Oh, inti għandek?

894
00:39:18,930 --> 00:39:20,350
Xi ħadd li qatt programmati qabel.

895
00:39:20,350 --> 00:39:21,750
Jridu jippruvaw idek fil
dan, fil-shirt aħmar?

896
00:39:21,750 --> 00:39:22,600
Come fuq up.

897
00:39:22,600 --> 00:39:25,320
Oh yeah, jaqgħu fuq up, jekk inti ma mind.

898
00:39:25,320 --> 00:39:27,586
Allura qatt ma programmati
qabel, x'hemm isem tiegħek?

899
00:39:27,586 --> 00:39:28,210
Lauren: Lauren.

900
00:39:28,210 --> 00:39:29,626
DAVID J. Malan: Lauren, id-dritt.

901
00:39:29,626 --> 00:39:31,150
Allura jiffissaw dan bug għalina.

902
00:39:31,150 --> 00:39:35,070
You ħadthom ma bbenefikawx C, preżumibbilment,
u probabbilment l-ebda lingwa oħra.

903
00:39:35,070 --> 00:39:38,380
Allura jiffissaw dan il-programm għalina.

904
00:39:38,380 --> 00:39:39,100
Nizza biex jissodisfaw ya.

905
00:39:39,100 --> 00:39:39,615
Ebda pressjoni.

906
00:39:39,615 --> 00:39:40,156
Lauren: Yeah.

907
00:39:40,156 --> 00:39:43,350

908
00:39:43,350 --> 00:39:46,270
>> DAVID J. Malan: Iżda għal darb'oħra, jekk dan
Gamble imur skond il-pjan,

909
00:39:46,270 --> 00:39:48,350
l takeaway hawn se
jkun, biss mill-ġdid, biex tibda

910
00:39:48,350 --> 00:39:51,080
li l-avviż mudelli u
jiddeduċu minn sintassi eżistenti

911
00:39:51,080 --> 00:39:55,420
kif inkella inti tista 'tesprimi
yourself, no pun maħsuba, sabiex

912
00:39:55,420 --> 00:39:58,410
biex jaqbdu xi xenarju addizzjonali.

913
00:39:58,410 --> 00:39:59,603
Allura aħna qed tgħid inkella jekk.

914
00:39:59,603 --> 00:40:04,040

915
00:40:04,040 --> 00:40:05,230
printf, tajba.

916
00:40:05,230 --> 00:40:09,120
U avviż ma CS50
IDE, u IDE frankly--

917
00:40:09,120 --> 00:40:11,110
stands għall Integrat
Ambjent iżvilupp.

918
00:40:11,110 --> 00:40:14,110
Huwa biss mod fancy ta 'tgħid
programm li jgħinek program.

919
00:40:14,110 --> 00:40:16,779
Hija ma affarijiet faċli għall-utent bħall-
meta inti tip parentesi waħda,

920
00:40:16,779 --> 00:40:18,320
awtomatikament tagħtik l-oħra.

921
00:40:18,320 --> 00:40:20,760
Il-preżunzjoni tkun li int
eventwalment tmur jridu tip li,

922
00:40:20,760 --> 00:40:22,400
u wkoll tagħmlu ma 'kwotazzjonijiet.

923
00:40:22,400 --> 00:40:24,190
>> So I simili linja 23.

924
00:40:24,190 --> 00:40:26,400
99% tal-mod hemmhekk.

925
00:40:26,400 --> 00:40:29,920
Xi ħadd tixtieq li Chime fi bil-ponta?

926
00:40:29,920 --> 00:40:31,420
Smajt virgola mill-udjenza.

927
00:40:31,420 --> 00:40:32,080
Tajba.

928
00:40:32,080 --> 00:40:33,260
Allura li tikkompleta dan.

929
00:40:33,260 --> 00:40:37,930
U issa, I biss ikollhom ftit
kosternazzjoni bil-linja 21.

930
00:40:37,930 --> 00:40:41,370
Kif irridu li tesprimi din?

931
00:40:41,370 --> 00:40:43,370
Dak kwistjoni irridu
li jistaqsu, taħseb?

932
00:40:43,370 --> 00:40:46,870

933
00:40:46,870 --> 00:40:50,330
Allura qabel staqsejna l-mistoqsija,
jekk n hija akbar minn żero, jagħmlu dan.

934
00:40:50,330 --> 00:40:51,870
Else, tagħmel dan.

935
00:40:51,870 --> 00:40:54,317
Għalhekk għandna bżonn li jagħżlu
mistoqsija li titlob hawn.

936
00:40:54,317 --> 00:40:55,192
UDJENZA: [inaudible]

937
00:40:55,192 --> 00:40:56,530
DAVID J. Malan: Tajba.

938
00:40:56,530 --> 00:40:58,290
Mela jekk n ugwali żero.

939
00:40:58,290 --> 00:41:01,140

940
00:41:01,140 --> 00:41:02,100
Eċċellenti.

941
00:41:02,100 --> 00:41:03,080
Mela ejja nieqaf hawn.

942
00:41:03,080 --> 00:41:04,850
Grazzi tant għall braving dan.

943
00:41:04,850 --> 00:41:10,890
Ħalli nagħtikom ftit ferm mistħoqqa
stress ballun, forsi hemm.

944
00:41:10,890 --> 00:41:11,900
Allura aħna qed kważi hemm.

945
00:41:11,900 --> 00:41:14,790
Fil-fatt, Lauren, jekk inti ma
moħħ, let me jagħmlu waħda tweak hawn,

946
00:41:14,790 --> 00:41:17,850
biss sabiex ikunu konsistenti anke ma
dak rajna fil Scratch, liema

947
00:41:17,850 --> 00:41:21,080
ma nixtieq li tagħmel mal-linji
21 u 24, just darb'oħra bbażati

948
00:41:21,080 --> 00:41:23,290
dwar kif għamilna dan fil Scratch, forsi?

949
00:41:23,290 --> 00:41:24,230
>> UDJENZA: Nimxu it up.

950
00:41:24,230 --> 00:41:25,605
>> DAVID J. Malan: Yeah, jġorrhom up.

951
00:41:25,605 --> 00:41:30,260
Allura l-kundizzjoni inkella, it-tielet, jew
raba, jew il-ħames, jew fergħa finali,

952
00:41:30,260 --> 00:41:34,100
għandha tabilħaqq jidħlu afterward,
u li jinsab biss permezz tal-konvenzjoni,

953
00:41:34,100 --> 00:41:36,047
sempliċiment għaliex jekk inti se.

954
00:41:36,047 --> 00:41:37,380
So I do bżonn li jagħmlu dan tweak.

955
00:41:37,380 --> 00:41:39,660
U għandi bżonn biex tpoġġi tiegħi
Brace kaboċċi lura hawn.

956
00:41:39,660 --> 00:41:42,700
U issa, dan il-programm se jiġbor.

957
00:41:42,700 --> 00:41:46,140
Aħna tant qrib, iżda hemm
bug ħafna, ħafna sottili.

958
00:41:46,140 --> 00:41:47,200
Ejja naraw x'jiġri.

959
00:41:47,200 --> 00:41:49,660
>> L-ewwel, let me imorru quddiem u zoom out.

960
00:41:49,660 --> 00:41:53,405
Jien ser jimxi 'l quddiem u
tip jagħmel kundizzjoni żero.

961
00:41:53,405 --> 00:41:55,070
Oh, I gideb.

962
00:41:55,070 --> 00:41:58,760
Issa l-kompilatur hija
attwalment pretty intelliġenti.

963
00:41:58,760 --> 00:42:00,950
U jien ma verament jifhem
huwa messaġġ ta 'żball.

964
00:42:00,950 --> 00:42:04,310
Jużaw ir-riżultat ta 'assenjazzjoni
bħala kundizzjoni mingħajr parentesi,

965
00:42:04,310 --> 00:42:05,740
hija apparentement ħażin.

966
00:42:05,740 --> 00:42:07,100
Imma dak ma jfisser?

967
00:42:07,100 --> 00:42:10,860
>> Ukoll għal darb'oħra, tfittex għal xejriet
fl kodiċi li konna rajna qabel,

968
00:42:10,860 --> 00:42:16,640
dak li huwa linja 17 fil-fatt tagħmel,
anki jekk Lauren maħsuba kemmxejn

969
00:42:16,640 --> 00:42:18,790
xort'oħra?

970
00:42:18,790 --> 00:42:19,290
Yeah.

971
00:42:19,290 --> 00:42:21,565
>> UDJENZA: [inaudible]

972
00:42:21,565 --> 00:42:22,440
DAVID J. Malan: Yeah.

973
00:42:22,440 --> 00:42:26,610
Mela ftakar-sinjal ugwali, apparentement
kif konna użati qabel, mhuwiex ugwali.

974
00:42:26,610 --> 00:42:29,240
Assenjazzjoni tagħha, minn lemin għax-xellug.

975
00:42:29,240 --> 00:42:33,810
Allura linja 17 fil-mument
hija kundizzjoni, u huwa

976
00:42:33,810 --> 00:42:37,890
eżekuzzjoni kodiċi ġewwa l parentesi,
imma meta dan il-kodiċi tesegwixxi,

977
00:42:37,890 --> 00:42:42,140
dak li qed jiġri għall-valur ta 'żero?

978
00:42:42,140 --> 00:42:45,250
X'qed jiġri lill-valur ta 'n?

979
00:42:45,250 --> 00:42:46,810
Issir żero.

980
00:42:46,810 --> 00:42:50,520
Mela jekk n qed issir żero,
u għal darb'oħra, bħala kull ġimgħa li għaddiet,

981
00:42:50,520 --> 00:42:54,690
aħna ġeneralment ngħidu li żero
hija falza u waħda hija vera,

982
00:42:54,690 --> 00:42:57,410
jew iva huwa wieħed u ebda huwa żero.

983
00:42:57,410 --> 00:42:59,590
Allura vera u falza, wieħed u 0.

984
00:42:59,590 --> 00:43:06,090
Jekk n bħala tal-linja 17 kien
minħabba l-valur 0, huwa żero vera?

985
00:43:06,090 --> 00:43:06,590
No

986
00:43:06,590 --> 00:43:08,280
Bħala definizzjoni, żero hija falza.

987
00:43:08,280 --> 00:43:10,860
Dik hija l-konvenzjoni aħna qed
ser riċiklaġġ għall miexja 'l quddiem.

988
00:43:10,860 --> 00:43:17,320
Allura se linji 18, 19, u 20
qatt japplikaw issa, loġikament?

989
00:43:17,320 --> 00:43:18,320
Huma ma jistgħux.

990
00:43:18,320 --> 00:43:21,640
Allura aħna staqsa l-mistoqsija
iżda pjuttost mhux preċiż,

991
00:43:21,640 --> 00:43:25,620
u inti ma tkunx taf dan sakemm
inti stajt tidher dan, is-soluzzjoni fis-C

992
00:43:25,620 --> 00:43:29,610
huwa meta inti tixtieq li jesprimu
ugwaljanza, inti tgħidli ugwali ugwali.

993
00:43:29,610 --> 00:43:33,140
Allura sinjal ugwali kien diġà uża sa
billi assenjazzjoni, mill-lemin għax-xellug.

994
00:43:33,140 --> 00:43:35,110
Ugwali ugwali mezzi ugwali.

995
00:43:35,110 --> 00:43:37,950
U jekk int verament tixtieq moħħok
li jiġu mgħawwġa, fil JavaScript u PHP,

996
00:43:37,950 --> 00:43:40,490
hemm ugwali ugwali ugwali, li
tfisser xi ħaġa oħra għal kollox,

997
00:43:40,490 --> 00:43:41,990
imma aħna ser jiksbu għal dak qabel twil.

998
00:43:41,990 --> 00:43:45,760
>> Allura dan huwa tiffissa sempliċi, iżda tirrealizza
super faċli biex jagħmlu dan l-iżball,

999
00:43:45,760 --> 00:43:48,700
u mbagħad nistaqsu u l-ġlieda
għall-minuti, jekk mhux siegħa,

1000
00:43:48,700 --> 00:43:51,490
għaliex huwa kodiċi tiegħi ma
eżekuzzjoni bħala I-intenzjoni?

1001
00:43:51,490 --> 00:43:54,140
Huwa għaliex inti ma tell
dan preċiżament dak li inti fisser.

1002
00:43:54,140 --> 00:43:56,450
Allura li kien kważi
perfetta, u kien kbir

1003
00:43:56,450 --> 00:44:00,760
li aħna stumbled madwar dawn iż-żewġ ftit
affarijiet għaliex issa jekk aħna jiffissaw għalihom,

1004
00:44:00,760 --> 00:44:06,240
u I do jagħmlu żero kondizzjoni
dot mmejla kundizzjoni żero,

1005
00:44:06,240 --> 00:44:07,490
Nixtieq integer jekk jogħġbok.

1006
00:44:07,490 --> 00:44:08,090
Ejja naraw.

1007
00:44:08,090 --> 00:44:09,160
No

1008
00:44:09,160 --> 00:44:10,740
Huwa ser seħħ lili biex tagħmel dan.

1009
00:44:10,740 --> 00:44:11,990
Allura 42.

1010
00:44:11,990 --> 00:44:13,590
I qabad numru pożittiv.

1011
00:44:13,590 --> 00:44:16,470
Allura issa kif nista 'jipprova
dan il-programm korretta?

1012
00:44:16,470 --> 00:44:19,990
Jekk int matematiku, inti ma tistax
verament jipprova dan bi prova u żball,

1013
00:44:19,990 --> 00:44:20,490
id-dritt?

1014
00:44:20,490 --> 00:44:23,180
Inti tista 'mhux biss prova mill
eżempju, iżda mill-inqas

1015
00:44:23,180 --> 00:44:25,494
bħala programmer aħna mhux qed
ser jippruvaw li tipprova għal issa

1016
00:44:25,494 --> 00:44:27,660
li dan huwa effettivament
korretta, imma I għandu probabbilment

1017
00:44:27,660 --> 00:44:29,470
test f'xi każijiet rappreżentattivi.

1018
00:44:29,470 --> 00:44:31,070
>> Stajt ttestjati 42.

1019
00:44:31,070 --> 00:44:33,030
I jistgħu jittestjaw 43.

1020
00:44:33,030 --> 00:44:34,910
I jistgħu jittestjaw 44.

1021
00:44:34,910 --> 00:44:35,640
Test 45.

1022
00:44:35,640 --> 00:44:36,140
Dritt?

1023
00:44:36,140 --> 00:44:37,860
Imma I jistgħu jagħmlu dan żmien twil verament.

1024
00:44:37,860 --> 00:44:39,925
Dak li jkun ftit aktar
każijiet interessanti li jippruvaw?

1025
00:44:39,925 --> 00:44:41,050
UDJENZA: [inaudible] żero.

1026
00:44:41,050 --> 00:44:41,740
DAVID J. Malan: Allura żero.

1027
00:44:41,740 --> 00:44:42,297
Ċertament.

1028
00:44:42,297 --> 00:44:44,880
U tajjeb, konna ltqajna dan iż-żmien,
grazzi għall-kodiċi ġdid Lauren.

1029
00:44:44,880 --> 00:44:46,213
X'hemm każ ieħor tajjeb biex tipprova?

1030
00:44:46,213 --> 00:44:47,320
UDJENZA: wieħed negattiv.

1031
00:44:47,320 --> 00:44:50,070
>> DAVID J. Malan: waħda negattiva, u
forsi xi ftit akbar,

1032
00:44:50,070 --> 00:44:52,617
hekk forsi negattiv 42,
iżda b'mod ġenerali, meta

1033
00:44:52,617 --> 00:44:54,450
ittestjar programmi tiegħek
nimxu 'l quddiem, int

1034
00:44:54,450 --> 00:44:56,325
tmur jridu jaħsbu
lilek innifsek, bħal dak

1035
00:44:56,325 --> 00:44:58,050
huma l-każijiet differenti fundamentali.

1036
00:44:58,050 --> 00:45:01,720
U jien DARE ngħid każ negattiv,
bħala każ pożittiv, u każ żero

1037
00:45:01,720 --> 00:45:03,365
pretty ħafna rawnds dawn jitwettqu.

1038
00:45:03,365 --> 00:45:04,990
Ejja nħarsu lejn varjant ta 'dan għalkemm.

1039
00:45:04,990 --> 00:45:06,930
Kundizzjonijiet wieħed.

1040
00:45:06,930 --> 00:45:11,224
Din hija soluzzjoni korretta hawnhekk,
sabiex tkun taf tara tnejn u online,

1041
00:45:11,224 --> 00:45:13,390
jekk inti timxi permezz tal-
walkthroughs, se ġeneralment

1042
00:45:13,390 --> 00:45:18,090
inkrement dawn gradwali sakemm aħna
jiksbu eżattament l-approċċ dritt.

1043
00:45:18,090 --> 00:45:20,070
X'jiġri jekk ridna li jistaqsu
żewġ mistoqsijiet f'daqqa?

1044
00:45:20,070 --> 00:45:22,200
>> Let me jiftħu din minflok.

1045
00:45:22,200 --> 00:45:26,740
Mhux swiċċ, għal raġunijiet
Ser naraw ieħor żmien.

1046
00:45:26,740 --> 00:45:29,610
X'hemm ġdid sintattikament hawn?

1047
00:45:29,610 --> 00:45:32,760
Jien bħalissa playing a game
fejn il-kompjuter li jgħidilhom

1048
00:45:32,760 --> 00:45:35,550
me, jagħtu me integer
bejn wieħed u 10,

1049
00:45:35,550 --> 00:45:37,180
u mbagħad jien tiġġudika input-utent.

1050
00:45:37,180 --> 00:45:39,180
Bl-Ingliż, ibbażati fuq
il-kodiċi tara hawn

1051
00:45:39,180 --> 00:45:41,530
bil-blu, dak li huwa dan il-programm tagħmel?

1052
00:45:41,530 --> 00:45:44,256

1053
00:45:44,256 --> 00:45:46,380
UDJENZA: [inaudible] qabad
numru kbir jew żgħir.

1054
00:45:46,380 --> 00:45:46,484
DAVID J. Malan: Yeah.

1055
00:45:46,484 --> 00:45:49,450
Huwa biss li tiddeċidi jekk
I qabad big, jew medju,

1056
00:45:49,450 --> 00:45:53,900
jew numru żgħir bbażata fuq ħafna
definizzjoni arbitrarja ta 'intrapriżi żgħar, medji,

1057
00:45:53,900 --> 00:45:58,510
u kbar hawn, iżda avviż
l sintassi li l-ġdida hija din.

1058
00:45:58,510 --> 00:46:02,340
M'hemm l-ebda inqas minn int jew ugwali għal
tiffirma, jew ikbar minn jew ugwali għal jiffirmaw,

1059
00:46:02,340 --> 00:46:05,430
fejn wieħed ikun fuq l-oħra, li inti
jistgħu jesprimu fil bħal Microsoft Word.

1060
00:46:05,430 --> 00:46:08,180
Allura fil-lingwa ta 'programmar inti
tipikament biss tagħmel żewġ karattri,

1061
00:46:08,180 --> 00:46:09,450
wieħed wara l-oħra.

1062
00:46:09,450 --> 00:46:12,695
U dan xi probabbilment
jirrappreżentaw, ampersand ampersand.

1063
00:46:12,695 --> 00:46:13,570
UDJENZA: [inaudible]

1064
00:46:13,570 --> 00:46:13,680
DAVID J. Malan: Yeah.

1065
00:46:13,680 --> 00:46:16,910
Dan ifisser biss u minħabba li
Jirriżulta li l-awturi ta 'C

1066
00:46:16,910 --> 00:46:19,120
użati ampersand wieħed,
li inti tista 'taħseb

1067
00:46:19,120 --> 00:46:22,430
tkun perfetta għall-kunċett
ta 'u, hija diġà użata up,

1068
00:46:22,430 --> 00:46:27,300
ampersand hekk ampersand attwalment
jaqbad il-każ aħna fil-fatt tixtieq.

1069
00:46:27,300 --> 00:46:30,610
>> Mela ejja issa stumble madwar żewġ affarijiet.

1070
00:46:30,610 --> 00:46:32,640
Let me imorru quddiem u tiftaħ wieħed.

1071
00:46:32,640 --> 00:46:36,590
Xi ħaġa li ftit tħassib.

1072
00:46:36,590 --> 00:46:37,970
Impreċiżjoni dot c.

1073
00:46:37,970 --> 00:46:40,260
Let me jintroduċu żewġ affarijiet hawn.

1074
00:46:40,260 --> 00:46:44,720
Waħda, avviż li nistgħu nagħmlu
matematika, kif eżatt bħal qabel meta

1075
00:46:44,720 --> 00:46:47,797
għamilna flimkien ma 'żewġ numri, xuy.

1076
00:46:47,797 --> 00:46:49,380
X'inhu dan il-programm apparentament tagħmel?

1077
00:46:49,380 --> 00:46:52,140
Stajt ma kkummentaw encore,
u stajt introdotti fil-mija f,

1078
00:46:52,140 --> 00:46:55,720
imma I malajr għidt qabel
mija f ifisser b'punt li jvarja

1079
00:46:55,720 --> 00:46:56,970
valur, li huwa numru reali.

1080
00:46:56,970 --> 00:46:59,520
Xi ħaġa ma 'deċimali
punt, li mhuwiex numru sħiħ.

1081
00:46:59,520 --> 00:47:02,270
What do you think dan il-programm huwa
jippruvaw juru lili fuq l-iskrin?

1082
00:47:02,270 --> 00:47:05,060

1083
00:47:05,060 --> 00:47:06,050
Yeah?

1084
00:47:06,050 --> 00:47:07,550
UDJENZA: Ir-riżultat ta 'wieħed fuq 10.

1085
00:47:07,550 --> 00:47:07,780
DAVID J. Malan: Yeah.

1086
00:47:07,780 --> 00:47:09,680
X'hemm-riżultat ta 'wieħed maqsum f'10.

1087
00:47:09,680 --> 00:47:12,721
Dritt, minħabba li kull wieħed inti għandek probabilment
kibret jafu li wieħed aktar minn 10

1088
00:47:12,721 --> 00:47:14,502
huwa dak?

1089
00:47:14,502 --> 00:47:16,220
Yeah, huwa biss 1/10 jew 0.1.

1090
00:47:16,220 --> 00:47:16,720
Dritt?

1091
00:47:16,720 --> 00:47:19,010
Mela ejja ara dak li dan fil-fatt hu.

1092
00:47:19,010 --> 00:47:21,010
So let me jimxi 'l quddiem u jiffrankaw din.

1093
00:47:21,010 --> 00:47:21,970
Let me jinżlu hawn.

1094
00:47:21,970 --> 00:47:26,360
Jagħmlu impreċiżjoni dot slash
nuqqas ta 'preċiżjoni, u avviż, wisq,

1095
00:47:26,360 --> 00:47:29,380
f'ambjent Linux, inti ma
għandek tip out nuqqas ta 'preċiżjoni u jieħdu

1096
00:47:29,380 --> 00:47:30,010
ġurnata kollha.

1097
00:47:30,010 --> 00:47:32,910
Hija ġeneralment, jekk inti hit Tab, huwa
se jispiċċaw ħsieb tiegħek għalik,

1098
00:47:32,910 --> 00:47:36,660
ibbażata fuq il-kliem li huma
disponibbli fid-direttorju kurrenti.

1099
00:47:36,660 --> 00:47:37,160
OK.

1100
00:47:37,160 --> 00:47:37,970
Allura inti kienu dritt.

1101
00:47:37,970 --> 00:47:41,239
Wieħed maqsum f'10 huwa, fil-fatt, 0.1.

1102
00:47:41,239 --> 00:47:42,280
Imma jien ftit kurjuż.

1103
00:47:42,280 --> 00:47:44,196
U jirriżulta printf
jappoġġja xi karatteristiċi

1104
00:47:44,196 --> 00:47:48,700
li biha inti tista 'tispeċifika aktar minn
in-numru default ta 'punti deċimali.

1105
00:47:48,700 --> 00:47:52,140
Mela jekk Irrid nara 10 deċimali
punti I tista 'tagħmel fil-mija,

1106
00:47:52,140 --> 00:47:55,510
għall-simbolu placeholder, dot
10 għal, jagħtu me 10 punti deċimali,

1107
00:47:55,510 --> 00:47:58,140
u mbagħad xorta punt floating
valur, u, bħala twarrib,

1108
00:47:58,140 --> 00:48:01,550
dak li huwa dan backslash n
apparentement inżommu tuża?

1109
00:48:01,550 --> 00:48:03,450
Jirriżulta huwa
simbolu għal linja ġdida.

1110
00:48:03,450 --> 00:48:05,970
Hu l-mod espliċitu ħafna
ta 'tgħid li l-kompjuter,

1111
00:48:05,970 --> 00:48:08,759
tmexxi l-cursor għall-ieħor
linja wara li inti qed isir.

1112
00:48:08,759 --> 00:48:10,800
U aħna ser tara x'jiġri
meta aħna ma tagħmel dan.

1113
00:48:10,800 --> 00:48:12,430
>> Let me recompile jagħmlu impreċiżjoni.

1114
00:48:12,430 --> 00:48:15,320

1115
00:48:15,320 --> 00:48:18,356
Issa dot mmejla impreċiżjoni.

1116
00:48:18,356 --> 00:48:18,930
OK.

1117
00:48:18,930 --> 00:48:19,780
Still dritt.

1118
00:48:19,780 --> 00:48:21,512
Wieħed maqsum f'10.

1119
00:48:21,512 --> 00:48:23,220
Issa jien jkollna
ftit kurjuż, għalkemm.

1120
00:48:23,220 --> 00:48:27,599
X'jiġri jekk I ħarsa 20 deċimali
jirrimarka, recompile, terġa 'ssir,

1121
00:48:27,599 --> 00:48:29,390
u bħala twarrib għal
veloċità, inti tista 'wkoll tuża

1122
00:48:29,390 --> 00:48:31,800
up tiegħek u 'l isfel vleġeġ biex
iscroll matul l-istorja tiegħek,

1123
00:48:31,800 --> 00:48:35,476
sabiex inti ma għandhomx iżommu
retyping dawn il-kmandijiet, jidħlu.

1124
00:48:35,476 --> 00:48:36,910
Huh.

1125
00:48:36,910 --> 00:48:39,220
I ma jitgħallmu li fl-iskola grad.

1126
00:48:39,220 --> 00:48:43,260
Kull dritt, so let me
tara bħal 29 postijiet barra.

1127
00:48:43,260 --> 00:48:44,300
Forsi huwa biss fluke.

1128
00:48:44,300 --> 00:48:46,907
Forsi kompjuter tiegħi qed jaġixxi stramb.

1129
00:48:46,907 --> 00:48:47,990
Li mhux xi ħaġa, id-dritt?

1130
00:48:47,990 --> 00:48:50,300
Huwa qed jagħmel xi ħaġa deterministically.

1131
00:48:50,300 --> 00:48:53,410
Sabiex tagħmel impreċiżjoni.

1132
00:48:53,410 --> 00:48:54,890
OK, li l-messed up.

1133
00:48:54,890 --> 00:48:57,620
Allura dak li qed jiġri?

1134
00:48:57,620 --> 00:49:00,160
>> Allura apparentement tiegħek
għalliem ġie tinsab

1135
00:49:00,160 --> 00:49:03,900
lilkom ilkoll ta 'dan iż-żmien għall
raġunijiet li aħna ser tara qabel twil.

1136
00:49:03,900 --> 00:49:05,569
Imma ejja aħħar ma 'programm ieħor.

1137
00:49:05,569 --> 00:49:07,860
Din hija programmi ftit
xi ħadd kiteb xi snin ilu,

1138
00:49:07,860 --> 00:49:08,990
u huwa attwalment parti minn konkors.

1139
00:49:08,990 --> 00:49:11,198
Ħadd ma attwalment jikteb kodiċi
bħal dan, u jekk inti tagħmel,

1140
00:49:11,198 --> 00:49:12,880
dan huwa stylistically problema.

1141
00:49:12,880 --> 00:49:14,660
Imma n-nies jagħmlu dan għall bragging drittijiet.

1142
00:49:14,660 --> 00:49:17,260
Biex tikteb l-aktar konfużjoni
tfittex programm li

1143
00:49:17,260 --> 00:49:19,110
madankollu ma xi ħaġa interessanti.

1144
00:49:19,110 --> 00:49:23,930
U n-nota ħsibt aħna'd leave
illum, qabel Colton jilgħab us out hawn,

1145
00:49:23,930 --> 00:49:27,840
huwa li tmexxi dan il-programm,
li, anki fi biss bl-użu

1146
00:49:27,840 --> 00:49:31,450
C f'dan ibbażat fuq test
ambjent, jagħtina dan.

1147
00:49:31,450 --> 00:49:32,264
Dammit.

1148
00:49:32,264 --> 00:49:34,930
>> [Rires]

1149
00:49:34,930 --> 00:49:36,800
>> Stand by.

1150
00:49:36,800 --> 00:49:39,340
[Inaudible] l m c sing.

1151
00:49:39,340 --> 00:49:42,885
Inti qed tmur biex tara d-maġika
incantation li aħna ser tara qabel twil.

1152
00:49:42,885 --> 00:49:45,780
[Inaudible] Kull dritt.

1153
00:49:45,780 --> 00:49:51,592
U issa inti tista 'anki
tagħmel affarijiet bħal dan.

1154
00:49:51,592 --> 00:49:52,340
Thats it.

1155
00:49:52,340 --> 00:49:56,410
Għal CS50 aħna, se tara int nhar il-Ġimgħa.

1156
00:49:56,410 --> 00:49:58,910
>> [Daqq tal-mużika]

1157
00:49:58,910 --> 00:52:38,390

1158
00:52:38,390 --> 00:52:41,440
>> [Applause]

1159
00:52:41,440 --> 00:52:42,812