1
00:00:00,000 --> 00:00:02,440
[Powered by Google Translate] [Wiki 7]

2
00:00:02,440 --> 00:00:04,730
[David J. Malan - Chuo Kikuu cha Harvard]

3
00:00:04,730 --> 00:00:07,490
[Hii ni CS50. - CS50.TV]

4
00:00:07,490 --> 00:00:12,280
Wote haki. Karibu tena. Hii ni CS50, na hii ni mwanzo wa wiki 7.

5
00:00:12,280 --> 00:00:14,690
michache ya matangazo kidogo:

6
00:00:14,690 --> 00:00:18,150
Pset5 ni sasa katika maendeleo, au hivi karibuni itakuwa,

7
00:00:18,150 --> 00:00:21,590
na napenda kusema, kabisa uaminifu, hii haina huwa na kuwa miongoni mwa changamoto zaidi

8
00:00:21,590 --> 00:00:24,460
wa seti kozi ya tatizo, hivyo basi mimi kutaja hili sasa

9
00:00:24,460 --> 00:00:28,190
hivyo kwamba wiki hii zaidi ya milele wewe usingoje mpaka, kusema, Jumatano usiku

10
00:00:28,190 --> 00:00:29,920
au Alhamisi usiku kwa kupiga mbizi in

11
00:00:29,920 --> 00:00:32,369
Hii ni dhahiri pset kuvutia. Tunadhani ni fun.

12
00:00:32,369 --> 00:00:36,110
Kama kweli kupata kikamilifu sahihi na unaweza kisha changamoto kinachojulikana Big Bodi,

13
00:00:36,110 --> 00:00:39,830
utakuwa na fursa ya mechi Wits na baadhi ya wafanyakazi wa kozi

14
00:00:39,830 --> 00:00:41,620
na baadhi ya wanafunzi wako.

15
00:00:41,620 --> 00:00:44,670
Nini Bodi Big ni ni mara moja una yako Spell-Checker kazi,

16
00:00:44,670 --> 00:00:48,860
wewe utakuwa na uwezo wa kwenda kwa cs50.net baada ya mbio amri,

17
00:00:48,860 --> 00:00:52,430
rena opt katika, na kisha kiasi cha muda na kiasi cha RAM na zaidi

18
00:00:52,430 --> 00:00:56,130
kwamba una kutumika katika utekelezaji yako itakuwa exhibited hapa nyumbani ukurasa kozi ya.

19
00:00:56,130 --> 00:00:59,740
Utagundua kuwa rundo zima la folks hizi hapa ni waliotajwa kama wafanyakazi

20
00:00:59,740 --> 00:01:04,220
tangu mwishoni mwa wiki, wafanyakazi walidhani itakuwa furaha kwa kujaribu outdo kila mmoja.

21
00:01:04,220 --> 00:01:07,390
Hivyo kutambua kwamba lengo hapa ni si kwa outdo wafanyakazi.

22
00:01:07,390 --> 00:01:09,790
Hata mimi tu hapa katika idadi ya 13.

23
00:01:09,790 --> 00:01:13,790
Rena opt katika, lakini ni fursa ya kuona jinsi tu kidogo RAM

24
00:01:13,790 --> 00:01:16,790
na jinsi wachache CPU sekunde unaweza kutumia vis-a-vis baadhi ya wanafunzi wako.

25
00:01:16,790 --> 00:01:20,540
>> Na mimi itabidi kukubali kwamba Kevin Michael Schmid,

26
00:01:20,540 --> 00:01:23,750
sasa katika idadi 1 nafasi kama moja ya TFS,

27
00:01:23,750 --> 00:01:28,120
hii ni utekelezaji kwamba sisi kuwaita haiwezekani

28
00:01:28,120 --> 00:01:32,700
kutokana na kwamba yeye kutumia RAM karibu na karibu sekunde 0 0 kwa upakiaji.

29
00:01:32,700 --> 00:01:35,670
Hivyo tutaweza kutunza offline Kevin. [Kicheko]

30
00:01:35,670 --> 00:01:40,950
Kuna baadhi ya ujuzi Kevin ni kuweka kwa mtihani hapa.

31
00:01:40,950 --> 00:01:45,280
Moja ya mambo sisi mawazo tunatarajia kufanya pia ni sasa CS50x ni wiki katika maendeleo,

32
00:01:45,280 --> 00:01:49,520
na wewe guys ni kama sehemu kubwa ya jaribio hili kama wale wanafunzi ni.

33
00:01:49,520 --> 00:01:53,720
Tumekuwa akawauliza kama sehemu ya pset0 yao, ambayo ilikuwa vile vile kuwasilisha mradi Scratch

34
00:01:53,720 --> 00:01:58,280
ya maslahi yao - mchezo, kipande maingiliano ya sanaa, uhuishaji, au kama -

35
00:01:58,280 --> 00:02:03,700
1 - 2 video kwa dakika, kama wangependa, kusema hello dunia na ambao wao kweli ni.

36
00:02:03,700 --> 00:02:06,780
Nilidhani ningependa kushiriki na wewe michache tu ya video ambayo yamekuwa in hivi sasa

37
00:02:06,780 --> 00:02:10,759
kwa sababu kwa ajili yetu, juu ya wafanyakazi angalau, ni kweli imekuwa kusisimua

38
00:02:10,759 --> 00:02:14,220
na msukumo wa kuona folks hizi kutoka duniani kote - nchi zote duniani kote -

39
00:02:14,220 --> 00:02:18,160
tuning katika, juu ya mambo yote, bila shaka kwa sayansi ya kompyuta kwenye mtandao,

40
00:02:18,160 --> 00:02:20,410
kama ni kwa sababu wanataka kuendelea yao masomo wenyewe,

41
00:02:20,410 --> 00:02:22,300
wanataka kuchukua kazi yao katika mwelekeo mpya,

42
00:02:22,300 --> 00:02:24,390
wanataka kujaza mapengo katika maarifa yao wenyewe,

43
00:02:24,390 --> 00:02:27,190
hivyo baadhi ya sababu moja kwamba wewe guys labda kuwa hapa.

44
00:02:27,190 --> 00:02:31,090
>> Basi, mimi kukupa moja vile mwanafunzi hapa. Unaweza kuongeza kiasi kidogo tu.

45
00:02:31,090 --> 00:02:35,520
Hapa ni moja ya maoni mwanafunzi wetu wa 1-dakika.

46
00:02:35,520 --> 00:02:40,380
Hello, ulimwengu. Mimi ni mwanafunzi wa uhandisi viwanda hapa katika Malaga, Hispania.

47
00:02:40,380 --> 00:02:45,840
Mimi msisimko juu ya kozi hii online kwa sababu nampenda sayansi ya kompyuta, kweli mimi,

48
00:02:45,840 --> 00:02:48,880
na mimi kweli kufahamu kwamba mimi kupata kuchunguza yake.

49
00:02:48,880 --> 00:02:51,940
Na ukweli kwamba naweza kujifunza huo wote wa guys kufanya

50
00:02:51,940 --> 00:02:57,040
lakini badala ya kuwa katika Harvard mimi ni katika Malaga, jinsi ya kushangaza ni kwamba?

51
00:02:57,040 --> 00:03:02,040
Naam, mimi Fernando, na hii ni CS50. Angalia guys wewe.

52
00:03:02,040 --> 00:03:07,100
[Kicheko] Mwingine clip sisi hasa kama, utapata kwamba Kiingereza hii muungwana ni si hivyo nguvu.

53
00:03:07,100 --> 00:03:11,520
Inaonekana kama yeye alikuwa ni mashine kutafsiriwa, hivyo tafsiri wenyewe ni kidogo si mkamilifu,

54
00:03:11,520 --> 00:03:15,790
lakini hii ilikuwa ni moja ya favorites yetu hivi sasa vilevile.

55
00:03:25,080 --> 00:03:29,980
[♪ ♪]

56
00:03:29,980 --> 00:03:32,370
Hello, ulimwengu. [Akizungumza katika Kijapani]

57
00:03:32,370 --> 00:03:39,830
[Nina kusalimia kwa Kijapani kwa sababu Kiingereza yangu ni wa uhakika.]

58
00:03:39,830 --> 00:03:45,380
[Nimeitia ujumbe kutoka kwa mji wa Gifu, Japan.]

59
00:03:45,380 --> 00:03:49,820
[Naweza kuwa mwanafunzi kwa mara ya kwanza katika miaka 20, kama inaweza kuonekana.]

60
00:03:49,820 --> 00:03:54,640
[Ninamshukuru sana kwa Chuo Kikuu cha Harvard ambaye alinipa nafasi hii na edX.]

61
00:03:54,640 --> 00:04:01,510
[Golf ni gitaa na kitu favorite mbio.] [Kicheko]

62
00:04:01,510 --> 00:04:05,750
[♪ ♪]

63
00:04:05,750 --> 00:04:10,790
[Kwa nini unafikiri mimi alikuwa anajaribu kuhudhuria cs50x.]

64
00:04:10,790 --> 00:04:14,990
[Chuo Kikuu cha Harvard, ni shauku yangu.]

65
00:04:14,990 --> 00:04:19,740
[Hasa kama mimi ni uwepo mbali aliishi katika Japan.]

66
00:04:19,740 --> 00:04:26,680
[Mimi alitaka kujaribu mara moja na ufahamu wa kuwepo kwa edX vile wakati.]

67
00:04:26,680 --> 00:04:32,500
[Je, unafikiri hivyo huna kuhusiana na umri wa kujifunza I.]

68
00:04:32,500 --> 00:04:38,350
[Cs50 ni hamu yangu. Jina langu ni Kazu, na hii ni cs50.]

69
00:04:38,350 --> 00:04:43,090
[♪ ♪] [applause na cheering]

70
00:04:43,090 --> 00:04:49,220
Mwingine favorite ya yetu ilikuwa hii kuwasilisha hapa kutoka kwa mtu.

71
00:04:51,070 --> 00:04:55,380
[♪ ♪] [Malan] Google ni kama wewe ni unfamiliar na meme hii.

72
00:04:55,380 --> 00:05:01,480
>> Na kisha mwisho, wanandoa wengine kwamba got posted kwamba labda kushinda tuzo adorable.

73
00:05:01,480 --> 00:05:06,820
[Wanafunzi] Aww! >> [Malan] Sisi itabidi kusikiliza. Hii ni mfupi, hivyo kusikiliza kwa makini.

74
00:05:08,580 --> 00:05:11,150
[Kike msemaji] Nini jina lako? >> Louie.

75
00:05:11,150 --> 00:05:16,120
[Kike msemaji] Nini hii? >> [Giggles] CS50. [Kicheko]

76
00:05:16,120 --> 00:05:19,510
[Malan] hakuwa mbili inachukua, ingawa.

77
00:05:19,510 --> 00:05:22,240
Hapa sisi kwenda, mwisho.

78
00:05:23,030 --> 00:05:26,980
Jina langu ni Louie, na hii ni CS50.

79
00:05:26,980 --> 00:05:30,250
[Kicheko] Hii basi ni CS50x.

80
00:05:30,250 --> 00:05:33,230
Asante kwa wale wote wa wewe wakati kufuatia pamoja nyumbani

81
00:05:33,230 --> 00:05:35,620
ambao wamekuwa wanashiriki hivi sasa.

82
00:05:35,620 --> 00:05:39,510
Leo, sisi kuhitimisha mjadala wetu wa miundo data,

83
00:05:39,510 --> 00:05:41,160
angalau baadhi ya msingi kabisa,

84
00:05:41,160 --> 00:05:44,760
na kisha sisi kuendelea mazungumzo yetu kuhusu HTML na mtandao programu.

85
00:05:44,760 --> 00:05:48,520
Hakika, tumekuwa alitumia iliyopita baadhi ya wiki saba kuangalia misingi ya programu -

86
00:05:48,520 --> 00:05:50,450
algorithms, miundo data, na kama -

87
00:05:50,450 --> 00:05:53,050
na C, kama unaweza kuwa na uzoefu hivi sasa,

88
00:05:53,050 --> 00:05:57,060
ni lazima si zaidi kupatikana ya lugha

89
00:05:57,060 --> 00:05:59,090
na ambayo kwa kutekeleza baadhi ya mawazo hayo.

90
00:05:59,090 --> 00:06:01,880
Na hivyo kuanzia wiki hii na wiki ijayo na kisha zifuatazo,

91
00:06:01,880 --> 00:06:07,110
tutaweza hatimaye kuwa na uwezo wa mpito kutoka C, ambayo ni ujumla inayojulikana kama lugha ya uungwana ngazi ya chini,

92
00:06:07,110 --> 00:06:11,190
mambo ngazi za juu, kati yao PHP, JavaScript, na kama,

93
00:06:11,190 --> 00:06:14,850
ambayo tutaweza kuona kuteka juu ya masomo sawa kwamba tumejifunza katika wiki chache zilizopita,

94
00:06:14,850 --> 00:06:19,430
lakini utapata kwamba kutangaza vitu kama arrays na meza hash na kutafuta na kuchagua

95
00:06:19,430 --> 00:06:23,370
kuwa rahisi sana kwa sababu lugha wenyewe tutaweza kuanza kutumia

96
00:06:23,370 --> 00:06:25,290
itakuwa na nguvu zaidi.

97
00:06:25,290 --> 00:06:27,410
Lakini kwanza, maombi ya miti.

98
00:06:27,410 --> 00:06:30,240
Ni kawaida sana siku hizi kwa haja ya compress habari.

99
00:06:30,240 --> 00:06:34,770
Katika mazingira gani ingekuwa unataka compress baadhi ya aina ya digital habari?

100
00:06:37,190 --> 00:06:39,670
>> Yeah. >> [Mwanafunzi] Wakati unahitaji kutuma zaidi ya Mtandao.

101
00:06:39,670 --> 00:06:41,450
Yeah, wakati unataka kutuma kitu juu ya mtandao.

102
00:06:41,450 --> 00:06:44,950
Kama unataka kupakua faili kubwa, ni bora kama mtu juu ya nyingine ya mwisho

103
00:06:44,950 --> 00:06:48,760
ina USITUMIE kwamba faili kwa kutumia muundo zip au kitu kama hicho

104
00:06:48,760 --> 00:06:53,760
hivyo kwamba wewe ni kutuma bits wachache kuliko ili vinginevyo kuambukizwa.

105
00:06:53,760 --> 00:06:55,500
Hivyo ni jinsi gani compress habari?

106
00:06:55,500 --> 00:07:00,540
Ni wote majipu chini kutumia bits wachache kuliko wanatakiwa na default.

107
00:07:00,540 --> 00:07:03,220
Lakini hii ni aina ya kitu curious kwa sababu kufikiri nyuma kwa wiki 0 na 1

108
00:07:03,220 --> 00:07:07,370
wakati sisi aliyesema kuhusu ASCII na binary na kuongelea ASCII hasa

109
00:07:07,370 --> 00:07:10,690
kama kutumia bits 8 kuwakilisha wa alfabeti

110
00:07:10,690 --> 00:07:16,120
hivyo kwamba barua ni kuwakilishwa na 65, Herufi za chini ni idadi 97,

111
00:07:16,120 --> 00:07:21,210
na hata hivyo wewe kuwakilisha 65 au 97, unatumia bits 7 au 8.

112
00:07:21,210 --> 00:07:24,120
Lakini catch ni kwamba kuna baadhi ya barua katika alfabeti ya Kiingereza

113
00:07:24,120 --> 00:07:26,230
ambayo si kama maarufu kama watu wengine.

114
00:07:26,230 --> 00:07:31,600
Z si maarufu kwamba wote, Q si maarufu kwamba wote, lakini na E ni super maarufu.

115
00:07:31,600 --> 00:07:37,280
Na bado kwa wote wa barua hizi, kwa default dunia anatumia idadi sawa ya bits, 8 tu.

116
00:07:37,280 --> 00:07:42,690
Hivyo ingekuwa si hivyo wamekuwa nadhifu kama badala ya kutumia bits 8 kwa kila barua,

117
00:07:42,690 --> 00:07:47,440
hata wengi infrequently kutumika kama Q na Z,

118
00:07:47,440 --> 00:07:51,910
nini kama sisi kutumika bits machache kwa ajili ya E na na S na barua maarufu

119
00:07:51,910 --> 00:07:55,000
na kutumika zaidi kwa bits barua chini maarufu,

120
00:07:55,000 --> 00:07:57,770
wazo kuwa optimize wacha kwa kesi ya kawaida,

121
00:07:57,770 --> 00:08:01,160
ambayo ni mandhari katika sayansi ya kompyuta ya kujaribu optimize nini kitatokea zaidi

122
00:08:01,160 --> 00:08:05,310
na kutumia zaidi kidogo wakati, kidogo nafasi zaidi kwenye mambo ambayo, yeah, inaweza kutokea

123
00:08:05,310 --> 00:08:07,680
lakini si lazima kama mara kwa mara.

124
00:08:07,680 --> 00:08:09,330
Basi hebu chukua mfano.

125
00:08:09,330 --> 00:08:12,610
>> Tuseme kwamba tunataka encode taarifa hizo kwa haki kwa ufanisi.

126
00:08:12,610 --> 00:08:15,090
Unaweza kuwa mzima kujua kitu kidogo kuhusu Morse kificho,

127
00:08:15,090 --> 00:08:17,450
na ni tabia mbaya wewe hakujua code halisi,

128
00:08:17,450 --> 00:08:21,750
lakini unaweza kukumbuka kwamba ni angalau mfululizo huu wa dots na dashes.

129
00:08:21,750 --> 00:08:26,640
Hii ni coding uungwana ufanisi, na taarifa kwamba barua maarufu - kwa mfano, E -

130
00:08:26,640 --> 00:08:28,980
anatumia mfupi beeps.

131
00:08:28,980 --> 00:08:31,740
Morse code ni wote kuhusu beep beep-beep--beep beep beep--na kufanya tani

132
00:08:31,740 --> 00:08:34,799
aidha kwa muda mfupi au muda mrefu.

133
00:08:34,799 --> 00:08:40,330
E, kama ulionyehsa kwa dot, ni super short beep, tu beep, na kwamba itakuwa kuwakilisha E.

134
00:08:40,330 --> 00:08:43,960
Kwa kulinganisha, T itakuwa beep tena, kama beep [prolongs sauti],

135
00:08:43,960 --> 00:08:45,710
na ambacho kitawakilisha T.

136
00:08:45,710 --> 00:08:48,840
Lakini kwamba bado pretty mfupi kwa sababu, kwa kulinganisha, kama ukiangalia Z,

137
00:08:48,840 --> 00:08:52,690
kueleza Z ungependa kwenda beep, beep [tena sauti], beep, beep [mfupi sauti].

138
00:08:52,690 --> 00:08:55,360
Hivyo ni tena kwa sababu ni chini ya kawaida.

139
00:08:55,360 --> 00:08:58,150
Lakini gotcha hapa ni kwamba Morse code ni kidogo kiujanja

140
00:08:58,150 --> 00:09:00,610
katika kwamba si mara moja decodable.

141
00:09:00,610 --> 00:09:07,350
Kwa mfano, tuseme kwamba wewe kusikia juu ya baadhi ya mwisho wa beep waya [short], beep [mrefu].

142
00:09:07,350 --> 00:09:12,480
Ni ujumbe gani mimi tu kupokea? dot na dash. Gani kwamba kuwakilisha?

143
00:09:12,480 --> 00:09:15,330
[Mwanafunzi] A. >> [Malan] Labda.

144
00:09:15,330 --> 00:09:18,270
Pia inaweza kuwa E ikifuatiwa na T.

145
00:09:18,270 --> 00:09:23,390
Kwa maneno mengine, Morse code, ingawa leverages kanuni hii ya optimizing kesi kona,

146
00:09:23,390 --> 00:09:26,250
haina kukopesha yenyewe decodability haraka.

147
00:09:26,250 --> 00:09:29,850
Hiyo ni, binadamu ambaye ni kusikia au kupokea dots hizi na dashes

148
00:09:29,850 --> 00:09:34,540
ina namna fulani takwimu nje ambapo mapumziko ni kati ya herufi,

149
00:09:34,540 --> 00:09:39,660
kwa sababu kama wewe sijui wapi wale mapumziko ni, unaweza kuwachanganya kwa ET au kinyume chake.

150
00:09:39,660 --> 00:09:43,880
>> Basi nini ili unaweza kufanya? Katika code Morse unaweza tu pause kati ya kila moja ya barua.

151
00:09:43,880 --> 00:09:47,660
Lakini pausing ni aina ya kukabiliana na hatua wote wa kasi ya mambo juu.

152
00:09:47,660 --> 00:09:52,880
Basi nini kama badala ya sisi kuja na code ambapo hapakuwa na hali hii mbaya

153
00:09:52,880 --> 00:09:56,570
ambapo E ni kiambishi awali, kwa mfano, ya -

154
00:09:56,570 --> 00:10:00,020
kwa maneno mengine, kama tunaweza kuhakikisha kwamba mifumo ni bado mfupi kwa barua maarufu

155
00:10:00,020 --> 00:10:04,850
muda mrefu kwa barua chini maarufu, lakini hakuna machafuko inawezekana?

156
00:10:04,850 --> 00:10:08,930
mtu mmoja kwa jina Huffman miaka iliyopita zuliwa mpango huu huitwa Huffman coding

157
00:10:08,930 --> 00:10:12,390
kwamba kweli leverages moja ya miundo data tumekuwa alitumia muda kidogo kuzungumza kuhusu

158
00:10:12,390 --> 00:10:16,560
wiki hii iliyopita, kwamba miti, binary miti hasa -

159
00:10:16,560 --> 00:10:19,710
mti binary maana ya kuwa hakuna zaidi ya watoto 2.

160
00:10:19,710 --> 00:10:22,720
Ina labda mtoto wa kushoto, labda mtoto wa kulia, na hiyo ni yake.

161
00:10:22,720 --> 00:10:26,510
Hivyo kudhani tu kwa ajili ya majadiliano ya kwamba mtu anataka kupeleka ujumbe

162
00:10:26,510 --> 00:10:31,270
kwamba inaonekana kama hii. Ni kamili nonsense lakini ni linajumuisha Kama, Bs, Cs, Ds, na Es Salaam.

163
00:10:31,270 --> 00:10:34,890
Na kama kweli kuhesabu juu wote wa Kama, Bs, Cs, Ds, na Es

164
00:10:34,890 --> 00:10:36,870
na kisha kugawanya na jumla ya idadi ya herufi,

165
00:10:36,870 --> 00:10:42,710
hii chati kidogo hapa anasema kwamba 45% ya barua ni Salaam, 20% ni Kama,

166
00:10:42,710 --> 00:10:45,010
10% Bs, na kadhalika.

167
00:10:45,010 --> 00:10:47,330
Hivyo kwa maneno mengine, kudhani kuwa string alinukuliwa huko

168
00:10:47,330 --> 00:10:49,080
ni baadhi tu ujumbe kwamba unataka kutuma.

169
00:10:49,080 --> 00:10:52,180
Hutokea kwa kuwa nonsense hivyo tu tunaweza kutumia kama barua chache iwezekanavyo,

170
00:10:52,180 --> 00:10:55,220
lakini ni kweli kwamba kesi E inabakia maarufu zaidi,

171
00:10:55,220 --> 00:11:01,450
A na B na C ni angalau maarufu, angalau ya barua hizi 5 za alfabeti.

172
00:11:01,450 --> 00:11:04,040
Hivyo ni jinsi gani tunaweza kwenda kuhusu kuja na encoding,

173
00:11:04,040 --> 00:11:08,430
encoding binary, mfano wa sekunde 0 na 1s kwa kila moja ya barua hizi

174
00:11:08,430 --> 00:11:14,820
katika namna kwamba E ni mfano mfupi na labda B na C ni kidogo tena mwelekeo,

175
00:11:14,820 --> 00:11:19,270
tena, wazo kuwa kuwa tunataka kutumia wachache bits zaidi ya muda

176
00:11:19,270 --> 00:11:21,790
na zaidi bits tu mara moja kwa wakati.

177
00:11:21,790 --> 00:11:26,070
Kulingana na Huffman coding, unaweza kuunda msitu wa miti.

178
00:11:26,070 --> 00:11:31,190
Kuna aina ya line hadithi hapa ambao unahusisha miti na pia mchakato wa kujenga yao juu.

179
00:11:31,190 --> 00:11:32,420
Hebu kuanza.

180
00:11:32,420 --> 00:11:36,140
>> Napendekeza kwamba kuanza kwa msitu huu, ili kuzungumza, ya miti 5,

181
00:11:36,140 --> 00:11:38,260
ambayo kila mmoja ni mti pretty kijinga.

182
00:11:38,260 --> 00:11:42,800
mti linajumuisha nodi moja tu, kama kuwakilishwa hapa na mduara.

183
00:11:42,800 --> 00:11:45,310
Basi kila mmoja wa mambo haya yanaweza kuwa struct C

184
00:11:45,310 --> 00:11:50,200
na ndani ya struct C inaweza kuwa kuelea anayewakilisha kuhesabu frequency

185
00:11:50,200 --> 00:11:52,510
na kisha labda Char anayewakilisha barua.

186
00:11:52,510 --> 00:11:56,470
Hivyo kufikiri ya nodi hiyo kama struct tu umri wowote C lakini, kwa sasa, ngazi za juu.

187
00:11:56,470 --> 00:12:01,230
Hii ni msitu wa miti 5, kila mmoja ambaye tu nodi moja.

188
00:12:01,230 --> 00:12:06,830
Nini Huffman mapendekezo ni kwamba sisi kuanza kuchanganya miti wale

189
00:12:06,830 --> 00:12:11,140
kwamba kuwa na makosa madogo ndani ya miti frequency kubwa kidogo

190
00:12:11,140 --> 00:12:13,490
kwa kuunganisha yao na node mpya mizizi.

191
00:12:13,490 --> 00:12:17,560
Hivyo kati ya barua hapa, taarifa kwamba kwa urahisi nimekuwa sorted yao kutoka kushoto kwenda kulia,

192
00:12:17,560 --> 00:12:21,420
ingawa si kwamba madhubuti muhimu, na taarifa kwamba nodes ndogo

193
00:12:21,420 --> 00:12:23,930
sasa ni 10% na 10%.

194
00:12:23,930 --> 00:12:28,940
Hivyo Huffman mapendekezo kwamba sisi kuunganisha wale 2 nodes ndogo ndani ya mti mpya

195
00:12:28,940 --> 00:12:34,450
kwa kuanzisha mpya mzazi nodi na kisha kutoa kuwa mzazi wa mtoto wa kushoto na mtoto wa kulia

196
00:12:34,450 --> 00:12:37,720
ambapo B ni kiholela kushoto na C ni kiholela haki.

197
00:12:37,720 --> 00:12:41,590
Na kisha Huffman inapendekezwa kwamba hebu sasa tu kufikiri ya mtoto wa kushoto

198
00:12:41,590 --> 00:12:44,790
katika moja ya miti hii daima kama kuwa na kuwakilishwa na 0

199
00:12:44,790 --> 00:12:47,890
na mtoto haki daima kama kuwa na kuwakilishwa na idadi 1.

200
00:12:47,890 --> 00:12:50,680
>> Haijalishi kama wewe flip yao ya muda mrefu kama wewe ni thabiti.

201
00:12:50,680 --> 00:12:54,650
Hivyo sasa tuna nne miti katika misitu hii.

202
00:12:54,650 --> 00:12:58,050
Na mimi kusema nne kwa sababu sasa mti upande wa kushoto -

203
00:12:58,050 --> 00:13:00,570
na si sana mti kwa maana kwamba kukua kwa njia hii,

204
00:13:00,570 --> 00:13:05,170
ni zaidi kama mti wa familia ambapo sasa 0.2 ni aina ya mzazi wa watoto wawili -

205
00:13:05,170 --> 00:13:07,930
taarifa kwamba katika mzazi kwamba tumepata 0.2.

206
00:13:07,930 --> 00:13:13,370
Tumeongeza makosa frequency ya watoto wawili na kupewa nodi mpya jumla.

207
00:13:13,370 --> 00:13:15,310
Hivyo sasa sisi tu kurudia utaratibu huu.

208
00:13:15,310 --> 00:13:19,490
Kupata mbili nodes ndogo na kisha kujiunga nao katika mti mpya

209
00:13:19,490 --> 00:13:21,380
na kisha kurudia utaratibu zaidi.

210
00:13:21,380 --> 00:13:26,390
Hivi sasa tuna wagombea wachache, 20%, 15%, na 20%.

211
00:13:26,390 --> 00:13:29,780
Katika kesi hiyo, tuna kuvunja tie. Tunaweza kufanya hivyo kiholela.

212
00:13:29,780 --> 00:13:31,540
Tunapaswa tu kufanya hivyo mara kwa mara.

213
00:13:31,540 --> 00:13:33,760
Katika kesi hiyo, mimi itabidi kiholela kwenda kwa moja upande wa kushoto,

214
00:13:33,760 --> 00:13:39,880
na mimi sasa kuunganisha% 20% 15 na kunipa mzazi mpya iitwayo 35%,

215
00:13:39,880 --> 00:13:46,310
ambao kushoto mtoto ni 0, ambaye ni haki ya mtoto ni 1, na sasa tuna tatu tu miti katika msitu.

216
00:13:46,310 --> 00:13:47,960
Unaweza labda kuona ambapo hii ni kwenda.

217
00:13:47,960 --> 00:13:51,150
Kama sisi kurudia mara kadhaa zaidi, sisi itawabidi moja tu kubwa mti,

218
00:13:51,150 --> 00:13:53,900
yote ambaye edges ni lebo na sekunde 0 na 1s.

219
00:13:53,900 --> 00:13:55,710
Hebu kufanya hivyo tena.

220
00:13:55,710 --> 00:14:02,600
35% ni shina la mti. 20% na 45%, hivyo sisi ni kwenda kuunganisha% 35 na 20%.

221
00:14:02,600 --> 00:14:05,610
Sasa tuna mti huu hapa. Sisi kuongeza wale pamoja, tuna 55%.

222
00:14:05,610 --> 00:14:07,910
Sasa kuna wawili tu miti katika msitu.

223
00:14:07,910 --> 00:14:11,900
Sisi kufanya hili moja ya mwisho ya muda, na hopefully mathematically frekvenser wote kuongeza up

224
00:14:11,900 --> 00:14:15,570
kwa sababu wanapaswa tangu sisi computed yao kutoka kupata-go na kuongeza hadi 100%.

225
00:14:15,570 --> 00:14:17,960
Na sasa tuna mti mmoja.

226
00:14:17,960 --> 00:14:20,580
Hivyo hii ni Huffman coding mti.

227
00:14:20,580 --> 00:14:24,400
Ni aina ya alichukua muda kupata kuna maneno, lakini ukweli ni pamoja na kwa kitanzi

228
00:14:24,400 --> 00:14:27,620
au na kazi ya kujirudia, unaweza kujenga jambo hili up pretty kufunga.

229
00:14:27,620 --> 00:14:32,440
Hivyo sasa sisi moja mpya wa nodi, na wote wa nodi hiyo ndani wamekuwa malloc'd,

230
00:14:32,440 --> 00:14:34,690
labda, njiani.

231
00:14:34,690 --> 00:14:38,650
Hivyo sasa wakati juu ya mti huu tuna 100%, lakini sasa ilani tuna njia

232
00:14:38,650 --> 00:14:43,780
kutoka hii mpya kubwa-kubwa-kubwa-grandparent yote ya kubwa-kubwa-kubwa-wajukuu

233
00:14:43,780 --> 00:14:45,930
njia yote chini, na yote ya majani.

234
00:14:45,930 --> 00:14:52,840
>> Nini sisi ni kwenda kufanya sasa ni kupendekeza kwamba ili kuwakilisha E barua,

235
00:14:52,840 --> 00:14:55,670
sisi tu kutumia namba 1. Kwa nini?

236
00:14:55,670 --> 00:15:01,000
Kwa sababu kama sisi traverse mti huu kutoka mizizi ya mwisho chini ya jani inayojulikana kama E,

237
00:15:01,000 --> 00:15:06,050
sisi kufuata moja tu makali, makali haki, na kwamba bila shaka katika labeled 1 ya juu kulia.

238
00:15:06,050 --> 00:15:11,550
Hivyo Kidokezo hapa kwa Huffman ilikuwa kwamba encoding E katika binary itakuwa tu kuwa 1.

239
00:15:11,550 --> 00:15:14,490
Na kwamba ni pretty damn ufanisi. Je, si kweli kupata yoyote ndogo kuliko hiyo.

240
00:15:14,490 --> 00:15:18,350
Kwa kulinganisha, ni kwenda kuwa kuwakilishwa, kama wewe kufuata mantiki,

241
00:15:18,350 --> 00:15:21,610
kwa nini muundo wa bits badala yake? 01.

242
00:15:21,610 --> 00:15:25,500
Hivyo kupata, sisi kuanza katika mizizi na sisi kwenda kushoto na kisha sisi kwenda kulia,

243
00:15:25,500 --> 00:15:28,580
ambayo ina maana sisi ikifuatiwa 0 na kisha 1.

244
00:15:28,580 --> 00:15:32,810
Hivyo tutakuwa kuwakilisha barua na mfano 0 na 1.

245
00:15:32,810 --> 00:15:36,010
Na sasa taarifa tayari tuna mali ya decodability haraka

246
00:15:36,010 --> 00:15:38,090
kwamba hatukuwa na katika code Morse.

247
00:15:38,090 --> 00:15:42,840
Hata ingawa wote wa mifumo haya ni pretty mfupi - E ni 1 kidogo, ni 2 bits -

248
00:15:42,840 --> 00:15:45,080
taarifa kwamba wao hawawezi kuwa na kuchanganyikiwa moja au nyingine,

249
00:15:45,080 --> 00:15:54,870
kwa sababu kama wewe angalia 1 ni got kuwa E, kama kuona 0 kisha 1 ni wazi got kuwa A.

250
00:15:54,870 --> 00:15:58,410
Vile vile, nini D? 001.

251
00:15:58,410 --> 00:16:01,440
Nini ni C? 0001.

252
00:16:01,440 --> 00:16:05,320
Na ni nini B? 0000.

253
00:16:05,320 --> 00:16:09,550
Na tena, kwa sababu kila barua sisi huduma ya juu ni katika majani

254
00:16:09,550 --> 00:16:13,890
na hakuna hata mmoja wao ni aina ya kati katika njia kutoka mizizi na majani,

255
00:16:13,890 --> 00:16:18,760
hakuna hatari ya conflating 2 barua 'encodings tofauti

256
00:16:18,760 --> 00:16:22,300
kwa sababu wote wa mifumo haya ni kidogo deterministic.

257
00:16:22,300 --> 00:16:25,280
0000 daima kuwa B.

258
00:16:25,280 --> 00:16:29,480
Hakuna kipingili mahali fulani katika kati ya kwamba unaweza kuwavurugia barua moja kwa nyingine.

259
00:16:29,480 --> 00:16:31,150
Basi nini maana hapa?

260
00:16:31,150 --> 00:16:35,080
>> barua maarufu - katika kesi hii E - imenipatia encoding mfupi,

261
00:16:35,080 --> 00:16:37,430
imenipatia ijayo mfupi encoding,

262
00:16:37,430 --> 00:16:41,390
A na B na C, ambayo sisi tayari alijua kutoka aina kupata-go walikuwa maarufu angalau

263
00:16:41,390 --> 00:16:45,390
mara kwa mara 10% kila, wao wamezipata encoding mrefu.

264
00:16:45,390 --> 00:16:49,410
Na hivyo nini maana ya hii sasa ni kwamba kama unataka kutuma ujumbe hiyo Komprimerade

265
00:16:49,410 --> 00:16:51,950
juu ya internet au katika barua pepe au kama,

266
00:16:51,950 --> 00:16:56,730
badala ya kutumia ASCII standard, unaweza kutuma ujumbe Huffman coded

267
00:16:56,730 --> 00:17:01,720
ambapo kama unataka kutuma E barua, kutuma kidogo tu moja.

268
00:17:01,720 --> 00:17:05,680
Kama unataka kutuma, kutuma bits 2, 01, badala ya kupeleka bits 8

269
00:17:05,680 --> 00:17:10,190
ikifuatiwa na bits mwingine 8 ikifuatiwa na bits mwingine 8 na kadhalika.

270
00:17:10,190 --> 00:17:11,940
Lakini kuna gotcha hapa.

271
00:17:11,940 --> 00:17:17,079
Ni si ya kutosha tu kujenga mti huu na kisha kuanza kutuma kutoka Alice kwa Bob

272
00:17:17,079 --> 00:17:20,010
mfupi kidogo mfano, kamba kutoka ASCII,

273
00:17:20,010 --> 00:17:23,140
kwa sababu Alice pia ina taarifa Bob ya kile

274
00:17:23,140 --> 00:17:26,880
kama Bob ni kwenda kuwa na uwezo wa kusoma ujumbe wake USITUMIE?

275
00:17:26,880 --> 00:17:30,770
[Inaudible mwanafunzi majibu] >> gani hiyo?

276
00:17:30,770 --> 00:17:32,310
[Inaudible mwanafunzi majibu] >> Of nini mti ni.

277
00:17:32,310 --> 00:17:35,160
Au hata zaidi hasa, nini wale encodings ni,

278
00:17:35,160 --> 00:17:39,010
hasa tangu wakati wa hadithi hii sisi alitoa wito hukumu kwa wakati mmoja.

279
00:17:39,010 --> 00:17:43,640
Kumbuka kwamba tulikuwa na pick kiholela kati ya pingili 2 tofauti 20%?

280
00:17:43,640 --> 00:17:49,800
Hivyo si kesi hiyo Bob, mpokeaji, unaweza tu upya mti juu yake mwenyewe

281
00:17:49,800 --> 00:17:53,390
kwa sababu labda yeye itakuwa kujenga mti milele hivyo tofauti kidogo kutoka Alice.

282
00:17:53,390 --> 00:17:56,670
Aidha, Bob hana hata kujua nini ujumbe halisi ni

283
00:17:56,670 --> 00:18:00,770
kwa sababu neno tu Alice ni kutuma yake, bila shaka, ni ujumbe Komprimerade.

284
00:18:00,770 --> 00:18:05,900
>> Hivyo samaki na compression kama hii ni kwamba, ndiyo, Alice inaweza kuokoa mengi yote ya bits

285
00:18:05,900 --> 00:18:09,900
kwa kutuma 1 kwa Barua na 01 kwa na kadhalika,

286
00:18:09,900 --> 00:18:15,180
lakini yeye pia ana kuwajulisha Bob nini ramani ni kati ya herufi na bits

287
00:18:15,180 --> 00:18:19,620
sababu hawawezi wazi wanategemea tu ASCII tena kama sisi siyo kutumia ASCII.

288
00:18:19,620 --> 00:18:22,200
Hivyo anaweza ama kumpeleka mti namna fulani -

289
00:18:22,200 --> 00:18:26,600
kuandika ni chini, kuhifadhi data kama binary au kitu kama hicho -

290
00:18:26,600 --> 00:18:30,280
au tu kutuma naye kidogo kudanganya karatasi, faili Excel, ambayo inaonyesha upangaji.

291
00:18:30,280 --> 00:18:36,480
Hivyo ufanisi wa compression kweli akubali kwamba ujumbe kwamba wewe ni kutuma

292
00:18:36,480 --> 00:18:40,230
ni pretty kubwa, angalau ukubwa wa kati,

293
00:18:40,230 --> 00:18:42,180
kwa sababu kama wewe ni kutuma ujumbe mfupi wa super,

294
00:18:42,180 --> 00:18:45,390
kama wewe tu unataka kutuma ujumbe BAD, ambayo hufanyika kuwa neno tunaweza Spell hapa,

295
00:18:45,390 --> 00:18:49,550
B-A-D, pengine wewe kwenda kutumia bits wachache,

296
00:18:49,550 --> 00:18:53,130
lakini samaki ni kama wewe pia kuwa na kuwajulisha kile Bob mti ni

297
00:18:53,130 --> 00:18:57,530
au nini wale encodings ni, wewe ni kwenda pengine outweigh yote ya akiba

298
00:18:57,530 --> 00:19:00,110
ya kuwa na mambo USITUMIE kwa kuanzia.

299
00:19:00,110 --> 00:19:02,210
Hivyo ni kweli anaweza kuwa kesi kwamba kama wewe jaribu compressing

300
00:19:02,210 --> 00:19:05,330
hata na kitu kama format zip file au unaweza kuwa ukoo na -

301
00:19:05,330 --> 00:19:07,780
pretty ndogo files, hata tupu files -

302
00:19:07,780 --> 00:19:10,930
wakati mwingine wale files ili kupata kubwa na si ndogo.

303
00:19:10,930 --> 00:19:14,320
Lakini realistically, ambayo hufanyika tu kwa ukubwa ndogo ya SVG,

304
00:19:14,320 --> 00:19:16,920
hivyo si kwenda kufanya faili gigabyte kuwa 2 gigabytes;

305
00:19:16,920 --> 00:19:19,480
sisi ni kweli kuzungumza ka au tu kilobytes wanandoa.

306
00:19:19,480 --> 00:19:22,330
>> Baadhi ya mipango kama zip ni smart kutosha kutambua kwamba,

307
00:19:22,330 --> 00:19:24,590
"Wewe ni kwenda kutumia bits zaidi compressing hii."

308
00:19:24,590 --> 00:19:27,460
"Basi mimi si bother compressing ni kwa ajili yenu wakati wote."

309
00:19:27,460 --> 00:19:30,160
Hivyo hii ni moja ya njia ya basi compressing Nakala format.

310
00:19:30,160 --> 00:19:32,300
Tunaweza kutekeleza kitu kama hiki katika C.

311
00:19:32,300 --> 00:19:35,370
Kwa mfano, hapa ni jinsi sisi wanaweza kuwakilisha nodi katika mti huu

312
00:19:35,370 --> 00:19:39,320
ambapo tuna Char kwa ishara, thamani floating kwa frequency,

313
00:19:39,320 --> 00:19:42,250
na kama tumeona na miundo yetu nyingine data, kuyatumia 2,

314
00:19:42,250 --> 00:19:47,080
1 kwa mtoto wa kushoto, 1 kwa haki, ama ya ambayo inaweza kuwa null,

315
00:19:47,080 --> 00:19:50,850
lakini kama si, lina maana ya mtoto wa kushoto na mtoto wa kulia.

316
00:19:50,850 --> 00:19:55,130
Hivyo hii ni kisha Huffman coding, na ni njia moja ambayo unaweza kwenda kuhusu compressing habari,

317
00:19:55,130 --> 00:19:57,880
na hakika moja ya wengi rahisi kutekeleza

318
00:19:57,880 --> 00:20:00,830
katika mazingira ya, wanasema, miundo ya wiki iliyopita data,

319
00:20:00,830 --> 00:20:03,250
ingawa hata kisasa zaidi algorithms zipo

320
00:20:03,250 --> 00:20:08,220
kwamba anaweza kufanya mabadiliko hata kisasa zaidi wa data zako.

321
00:20:08,220 --> 00:20:11,640
Maswali yoyote juu ya basi miti, miti binary, au compression ya maandishi?

322
00:20:11,640 --> 00:20:15,590
[Mwanafunzi] Je, kuna utata fulani, kama ikiwa [inaudible] iligawanyika katika 01,

323
00:20:15,590 --> 00:20:19,160
kisha 011 itakuwa mafumbo, haki?

324
00:20:19,160 --> 00:20:22,730
[Inaudible] >> Bora swali. Utata.

325
00:20:22,730 --> 00:20:25,940
Hebu muhtasari kwa akimaanisha hii picha hapa.

326
00:20:25,940 --> 00:20:29,650
Kwa sababu wewe ni wahusika compressing, uwakilishi wa,

327
00:20:29,650 --> 00:20:32,850
kwa ufafanuzi wa algorithm hii daima kubaki majani,

328
00:20:32,850 --> 00:20:41,870
hutaweza ajali kutumia mfano huo wa bits kwa kiambishi awali ya barua nyingi.

329
00:20:41,870 --> 00:20:46,740
Hivyo kwa maneno mengine, wewe ni wasiwasi kuhusu, inaonekana kama, utata kutokana

330
00:20:46,740 --> 00:20:51,580
ambapo 001 inaweza kuwa mwanzo wa B au mwanzo wa C au kitu kama hicho.

331
00:20:51,580 --> 00:20:56,780
Lakini hiyo inaweza kuwa kesi kwa sababu taarifa kwamba wote wa herufi za alfabeti tuko usimbaji

332
00:20:56,780 --> 00:20:58,290
ni katika majani.

333
00:20:58,290 --> 00:21:01,910
>> ambiguity unaweza tu kujitokeza, kama katika kesi ya code Morse,

334
00:21:01,910 --> 00:21:06,770
ikiwa, kwa mfano, C alikuwa mahali fulani njiani kutoka mizizi kwa B.

335
00:21:06,770 --> 00:21:12,290
[Mwanafunzi] Haki. Hivyo katika kesi hiyo, wanasema ina majani 2. >> Sema ina - Sema kwamba tena.

336
00:21:12,290 --> 00:21:18,760
[Mwanafunzi] Sema ina majani 2, F na G, na kisha G - >> Sawa. Lakini hawawezi.

337
00:21:18,760 --> 00:21:23,230
yenyewe hakuweza kuwa majani F na G kwa sababu barua hizo F na G

338
00:21:23,230 --> 00:21:27,560
ingekuwa wenyewe kuwa majani fulani ya kushoto ya B au haki ya E.

339
00:21:27,560 --> 00:21:28,900
Hivyo kwa ufafanuzi, ni lazima kuwa na majani.

340
00:21:28,900 --> 00:21:32,940
Vinginevyo, uko sahihi kabisa, tumekuwa si kutatuliwa tatizo kwamba Morse code nyuso.

341
00:21:32,940 --> 00:21:38,150
Nzuri swali. Maswali mengine? Wote haki.

342
00:21:38,150 --> 00:21:42,050
Dhana hii ya bits, zinageuka tumekuwa alikuwa na nguvu ya wote pamoja kwamba tumekuwa si kweli kutumika

343
00:21:42,050 --> 00:21:44,200
wakati alikuja kufanyia haya sekunde 0 na 1s.

344
00:21:44,200 --> 00:21:46,600
Tuliuliza kuhusu hili kwenye moja ya seti ya mwanzo tatizo:

345
00:21:46,600 --> 00:21:52,340
yaani, ni jinsi gani wewe kwenda juu ya kuwabadili uppercase kwa Herufi za chini au kinyume chake?

346
00:21:52,340 --> 00:21:55,460
Au, zaidi concretely, mmoja wa wale psets kwanza aliuliza

347
00:21:55,460 --> 00:22:01,090
wangapi bits je kweli kuwa flip ili kubadili kwa Herufi za chini au kinyume chake?

348
00:22:01,090 --> 00:22:05,580
Hapa ni ukumbusho ya haraka ya nini 65 na 97 katika kuangalia kama binary.

349
00:22:05,580 --> 00:22:08,060
Na hata kama swali kwamba ina aina ya Faded katika kumbukumbu yako,

350
00:22:08,060 --> 00:22:11,290
unaweza kuona tena hapa kwamba wangapi bits haja ya kuwa na flipped

351
00:22:11,290 --> 00:22:15,810
kubadili mtaji wa Herufi za chini? Moja tu.

352
00:22:15,810 --> 00:22:19,650
>> Wao tu tofauti katika eneo moja, kidogo ya tatu kutoka kushoto.

353
00:22:19,650 --> 00:22:24,240
Ambapo ina 010, kidogo ina 011.

354
00:22:24,240 --> 00:22:26,250
Hivyo kwa namna fulani, tunahitaji tu kuwa na uwezo wa flip kwamba kidogo,

355
00:22:26,250 --> 00:22:29,410
na tunaweza basi capitalize au Herufi za chini barua.

356
00:22:29,410 --> 00:22:32,720
Tumefanya hii katika siku za nyuma kwa kweli kwa kutumia kama hali ya

357
00:22:32,720 --> 00:22:35,930
na kuangalia kama barua ni kati ya mji mkuu na mji mkuu A Z,

358
00:22:35,930 --> 00:22:41,480
kisha matokeo kama - a + 26 au kitu kama hicho.

359
00:22:41,480 --> 00:22:46,130
Wewe pengine alifanya mabadiliko hesabu kwa herufi za alfabeti.

360
00:22:46,130 --> 00:22:49,270
Lakini nini kama tunaweza tu flip kwamba moja kidogo?

361
00:22:49,270 --> 00:22:59,080
Jinsi gani unaweza kwenda juu ya kuchukua thamani moja Byte ya bits, hivyo 8 bits kama 01,000,001 na 01,100,001?

362
00:22:59,080 --> 00:23:03,170
Kama alikuwa na mwelekeo wa wale wa bits, jinsi gani tunaweza kwenda juu ya kubadilisha tu mmoja wao?

363
00:23:03,170 --> 00:23:07,610
Nini kama sisi kuanzisha katika njano hapa ruwaza hii nyingine ya bits?

364
00:23:07,610 --> 00:23:13,420
Kama mimi kufanya zima sekunde 0 string njano ila kwa kidogo moja kwamba mimi unataka kubadilisha

365
00:23:13,420 --> 00:23:17,900
na kisha mimi kuanzisha operator mpya inayojulikana kama operator bitwise -

366
00:23:17,900 --> 00:23:21,210
bitwise kwa maana kwamba kazi kwenye bits mtu binafsi,

367
00:23:21,210 --> 00:23:25,360
si juu ya Byte nzima au ka nne wote mara moja.

368
00:23:25,360 --> 00:23:31,170
Hii bar wima huko katika njano unaonyesha kwamba nini kama sisi kuchukua ya uwakilishi wa mji mkuu

369
00:23:31,170 --> 00:23:37,060
na bitwise AU kwa mlolongo wa manjano bits?

370
00:23:37,060 --> 00:23:41,300
Kwa maneno mengine, kufikiri nyuma kwa majadiliano yetu ya misemo Boolean katika Scratch na kisha katika C.

371
00:23:41,300 --> 00:23:47,520
>> Kufanya Boolean au ina maana kwamba kuwa ni kweli, ama kitu kwanza ina kuwa kweli

372
00:23:47,520 --> 00:23:50,700
au kitu pili ina kuwa kweli au wao wote wana kwa kuwa ni kweli,

373
00:23:50,700 --> 00:23:53,270
na kisha kusababisha pato ni yenyewe kweli.

374
00:23:53,270 --> 00:24:00,230
Katika kesi hii hapa, je, sisi kupata kama sisi kuchukua 0 "au" ed na 0? Uongo au uongo?

375
00:24:00,230 --> 00:24:04,280
Ni bado uongo, hivyo lowercase bado kama ilivyotarajiwa.

376
00:24:04,280 --> 00:24:07,540
Nini kama badala ya sisi kufanya au 1 0?

377
00:24:07,540 --> 00:24:12,640
Hii sasa bado 1, lakini taarifa nini kuhusu kutokea hapa.

378
00:24:12,640 --> 00:24:18,630
Kama sisi kuanza na mtaji na sisi kuendelea "au" yake bits mtu binafsi kama sisi ni kufanya hapa,

379
00:24:18,630 --> 00:24:25,180
0 au mmoja wa manjano inatupa nini hapa chini? Hii inatupa 1.

380
00:24:25,180 --> 00:24:35,120
Kwa kweli, tuseme hatukujua nini toleo uppercase ya kweli ilikuwa kidogo.

381
00:24:35,120 --> 00:24:38,270
Hebu kwenda kufanya hili. Hebu hoja hii nyuma zaidi ya hapa.

382
00:24:38,270 --> 00:24:42,340
Hebu kufanya hii tena. 0 0 au anitiaye 0.

383
00:24:42,340 --> 00:24:45,020
1 au 0 anitiaye 1.

384
00:24:45,020 --> 00:24:48,020
0 au 1 anitiaye 1.

385
00:24:48,020 --> 00:24:52,880
0 0 au anitiaye 0. moja ijayo ni 0, moja ijayo ni 0, moja ijayo ni 0.

386
00:24:52,880 --> 00:24:55,660
1 au 0 anitiaye 1.

387
00:24:55,660 --> 00:24:59,140
Na hivyo hata kama hatukujua mapema kile Herufi za chini ilikuwa,

388
00:24:59,140 --> 00:25:04,770
tu kwa "au" ing na muundo huu wa bits kwamba tumekuwa iliyotolewa hapa katika njano,

389
00:25:04,770 --> 00:25:09,400
unaweza Herufi za chini mtaji kwa flipping kwamba kidogo.

390
00:25:09,400 --> 00:25:11,580
Sisi alitumia usemi wiki iliyopita: flipping kidogo.

391
00:25:11,580 --> 00:25:13,710
Jinsi gani unaweza kweli kufanya kwamba programmatically?

392
00:25:13,710 --> 00:25:16,390
Unatumia nini ujumla iitwayo mask, mfululizo wa bits,

393
00:25:16,390 --> 00:25:19,980
kwamba katika kesi hii tu hivyo hutokea kuangalia kama idadi hii hapa,

394
00:25:19,980 --> 00:25:22,980
na kisha wewe "au" ni pamoja kutumia hii mpya C operator,

395
00:25:22,980 --> 00:25:29,940
si | |, unatumia moja | na wewe ingekuwa kweli kupata jibu hili hapa kwa sababu kwa nini?

396
00:25:29,940 --> 00:25:35,120
Hii ni mahali 1s, 2S mahali, 4s, 8s, 16S, 32s.

397
00:25:35,120 --> 00:25:42,280
Hivyo ni zinageuka kuwa kama wewe kuchukua barua mtaji na bitwise AU kwa 32 integer,

398
00:25:42,280 --> 00:25:47,520
kwa sababu 32 integer, wakati ukiangalia hiyo kama bits, inaonekana kama hii,

399
00:25:47,520 --> 00:25:50,860
hiyo ina maana unaweza flip kidogo kwamba wewe kweli unataka.

400
00:25:50,860 --> 00:25:52,630
Na vile vile - na tutaangalia code katika muda tu -

401
00:25:52,630 --> 00:25:54,210
tuseme tunataka kwenda upande mwingine.

402
00:25:54,210 --> 00:25:58,210
>> Jinsi gani unaweza kwenda kutoka mji mkuu lowercase kwa? Ambayo inahitaji mabadiliko kidogo?

403
00:25:58,210 --> 00:25:59,820
Ni moja moja.

404
00:25:59,820 --> 00:26:03,970
Tunataka mabadiliko ya kwamba kidogo ya tatu 1-0.

405
00:26:03,970 --> 00:26:06,310
Na jinsi tunavyoweza kwenda juu ya kufanya hii?

406
00:26:06,310 --> 00:26:10,130
Jinsi gani sisi kugeuka mbali kidogo? Kwa nini mfano wa bits tunaweza kugeuka mbali kidogo?

407
00:26:11,580 --> 00:26:14,070
Nini kama sisi aina ya Geuza mask?

408
00:26:14,070 --> 00:26:17,350
Wakati kabla, sisi mzima manjano mask sekunde 0

409
00:26:17,350 --> 00:26:19,930
isipokuwa kwa kidogo moja tulitaka kurejea kwenye,

410
00:26:19,930 --> 00:26:25,580
nini kama wakati huu, sisi kufanya yote mask 1s isipokuwa kwa kidogo kwamba tunataka kugeuka mbali

411
00:26:25,580 --> 00:26:28,330
na kisha kutumia kile operator?

412
00:26:28,330 --> 00:26:30,560
Nini kama sisi "na" mambo? Hebu tuangalie.

413
00:26:30,560 --> 00:26:34,880
Kama sisi sasa flip na hii, tuseme kwamba mimi tena kujenga mask kwamba wote 1s

414
00:26:34,880 --> 00:26:37,650
isipokuwa kwa kidogo moja kwamba mimi nataka kuzima

415
00:26:37,650 --> 00:26:43,860
na kisha badala ya "au" namba nyeupe juu juu na idadi ya njano chini hapa,

416
00:26:43,860 --> 00:26:46,940
nini kama mimi badala yake "na" yao pamoja? Ni wito bitwise na.

417
00:26:46,940 --> 00:26:49,450
Kimantiki, ni kitu kimoja kama Boolean na.

418
00:26:49,450 --> 00:26:55,160
Hii inanipa 0 & 1 ni 0. Hivyo uongo na kweli ni uongo.

419
00:26:55,160 --> 00:26:58,160
Kweli na kweli ni kweli.

420
00:26:58,160 --> 00:27:04,020
Na hapa ni uchawi: Kweli na uongo ni uongo sasa, hivyo tumekuwa akageuka mbali kwamba kidogo.

421
00:27:04,020 --> 00:27:06,560
Na sasa wengine wa hadithi fulani ni moja kwa moja.

422
00:27:06,560 --> 00:27:11,970
Kwa sababu ya mapumziko ya mask ni 1s, haijalishi nini idadi ni nyeupe.

423
00:27:11,970 --> 00:27:15,580
Wakati wewe "na" kitu kwa kweli, wewe si kwenda na mabadiliko ya thamani yake.

424
00:27:15,580 --> 00:27:20,200
Kama ni kweli, itakuwa kubaki kweli. Kama ilikuwa uongo, itakuwa kubaki uongo.

425
00:27:20,200 --> 00:27:23,190
>> Lakini uchawi hutokea wakati wewe kuchukua kitu ambacho ni kweli

426
00:27:23,190 --> 00:27:25,430
na wewe basi, "na" kwa uongo.

427
00:27:25,430 --> 00:27:30,030
Hii ina athari ya kugeuka mbali ya kuwa kidogo.

428
00:27:30,030 --> 00:27:31,980
Hivyo cryptic kidogo huko.

429
00:27:31,980 --> 00:27:35,390
Hebu kweli kuangalia code baadhi, ambayo ili kweli kuangalia hata zaidi cryptic,

430
00:27:35,390 --> 00:27:38,220
lakini hebu tuangalie hapa tolower.

431
00:27:38,220 --> 00:27:45,880
Kama mimi kuangalia tolower, kwenda kutoka mji mkuu wa Herufi za chini,

432
00:27:45,880 --> 00:27:47,730
hebu angalia jinsi tuweze kutekeleza mpango huu.

433
00:27:47,730 --> 00:27:51,280
Hapa ni kuu, na si kuchukua hoja amri yoyote-line.

434
00:27:51,280 --> 00:27:55,980
Mimi kutangaza c tabia kwa barua kwamba mtumiaji anaenda aina in

435
00:27:55,980 --> 00:28:00,690
Mimi kisha kutumia do familiar wakati kitanzi tu kuhakikisha kwamba mtumiaji dhahiri anitiaye mtaji

436
00:28:00,690 --> 00:28:05,010
au B au C. .. Z, hivyo nipe kitu kati na Z.

437
00:28:05,010 --> 00:28:08,580
Na sasa nini mimi nafanya nini hapa?

438
00:28:08,580 --> 00:28:14,870
Mimi nina "au" hii ing na 0x20, lakini hiyo ni kweli sawa -

439
00:28:14,870 --> 00:28:19,500
na tutaweza kurudi huu katika wakati - 32.

440
00:28:19,500 --> 00:28:24,830
Hivyo tena, 32 ni muundo huu wa bits hapa. Kwa nini sisi kujua hili?

441
00:28:24,830 --> 00:28:26,320
Hebu fikiria nyuma wiki 0.

442
00:28:26,320 --> 00:28:31,010
Hii ni mahali 1s, 2S mahali, 4s, 8s, 16S, 32s mahali.

443
00:28:31,010 --> 00:28:33,470
Hivyo hii idadi ya njano hutokea kwa kuwa 32.

444
00:28:33,470 --> 00:28:40,570
Naweza kuchukua sehemu ya barua kama Char hapa, bitwise "au" kwa idadi halisi 32,

445
00:28:40,570 --> 00:28:45,250
na nini mimi kupata nyuma? toleo lowercase ya kwamba Char.

446
00:28:45,250 --> 00:28:48,830
wakati uliopita, ingawa, mimi walionyesha hii katika nukuu mbalimbali ya msingi.

447
00:28:48,830 --> 00:28:51,370
Nini hii kuwakilisha? >> [Mwanafunzi] hexadesimoli.

448
00:28:51,370 --> 00:28:53,050
[Malan] Hii hutokea kwa kuwakilisha hexadesimoli.

449
00:28:53,050 --> 00:28:55,170
Sisi si aliyesema kuhusu hexadesimoli yote kwamba mengi,

450
00:28:55,170 --> 00:28:57,330
lakini ni kweli rahisi katika kesi kama hii.

451
00:28:57,330 --> 00:29:01,730
>> Hata ingawa inaonekana ngumu zaidi na hata kama inaonekana kama 20 na si 32,

452
00:29:01,730 --> 00:29:06,240
zinageuka kuwa hexadesimoli ni kweli super rahisi nukuu

453
00:29:06,240 --> 00:29:10,810
kwa sababu katika kila hexadesimoli tarakimu baada 0x - na hii si kitu;

454
00:29:10,810 --> 00:29:13,960
hii ni binadamu mkataba kwamba anasema hapa inakuja idadi hexadesimoli -

455
00:29:13,960 --> 00:29:18,590
kila ya tarakimu hizi, 2 na kisha 0, wao wenyewe inaweza kuwakilishwa

456
00:29:18,590 --> 00:29:20,800
na hasa 4 bits.

457
00:29:20,800 --> 00:29:27,840
Hivyo kama sisi kufanya hivyo, basi mimi kufungua mhariri Nakala hapa - weird oto kukamilisha -

458
00:29:27,840 --> 00:29:35,940
kama sisi kufanya Nakala kidogo mhariri hapa, 0x20 idadi maana hapa ni 4 bits, hapa mwingine bits 4.

459
00:29:35,940 --> 00:29:38,050
Hebu kufanya rightmost bits 4 kwanza.

460
00:29:38,050 --> 00:29:44,690
0 wakati kuwakilishwa na bits 4 ni nini? Super rahisi. Tu wote sekunde 0.

461
00:29:44,690 --> 00:29:46,780
Hivyo 4 bits kama sekunde 0.

462
00:29:46,780 --> 00:29:53,510
Jinsi gani unaweza kuwakilisha 2? Ni muda tangu sisi alifanya hivyo, lakini ni 0,100.

463
00:29:53,510 --> 00:29:57,310
Hivyo hii ni mahali 1s, hii ni mahali 2S, na kisha Haijalishi nini maeneo mengine ni.

464
00:29:57,310 --> 00:30:00,610
Kwa maneno mengine, katika hexadesimoli unaweza kusema 0x20,

465
00:30:00,610 --> 00:30:04,340
lakini kama wewe basi kufikiri kuhusu nini ni 2 na ni jinsi gani kuwakilishwa katika binary,

466
00:30:04,340 --> 00:30:07,130
kile ni 0 na ni jinsi gani kuwakilishwa katika binary,

467
00:30:07,130 --> 00:30:10,440
majibu ya maswali hayo ni hii na hii, kwa mtiririko huo.

468
00:30:10,440 --> 00:30:14,380
Hivyo 0x20 kinachotokea kwa kuwakilisha muundo huu wa bits 8,

469
00:30:14,380 --> 00:30:16,880
ambayo ni just mask kwamba tulitaka.

470
00:30:16,880 --> 00:30:20,140
Hivyo hii ni kwa muda tu zoezi miliki,

471
00:30:20,140 --> 00:30:24,520
lakini ukweli ni katika code ni kawaida zaidi ya kawaida ya kuandika constants kama hii

472
00:30:24,520 --> 00:30:28,360
katika hexadesimoli kwa sababu kisha unaweza programu kiasi urahisi,

473
00:30:28,360 --> 00:30:32,560
hata kama ni inahitaji baadhi ya karatasi na penseli, kufikiri nini kwamba mfumo wa bits ni

474
00:30:32,560 --> 00:30:35,960
kwa sababu huwezi kueleza sekunde 0 na 1s kawaida katika code.

475
00:30:35,960 --> 00:30:38,540
Huwezi kwenda 00,010 na kadhalika.

476
00:30:38,540 --> 00:30:42,380
>> Una kuchukua notations decimal au hexadesimoli au octal au nyingine.

477
00:30:42,380 --> 00:30:47,540
Watu wengi huwa na pick hexadesimoli tu ili tarakimu kila inawakilisha bits 4

478
00:30:47,540 --> 00:30:49,320
na unaweza kufanya hili math haraka.

479
00:30:49,320 --> 00:30:54,990
Na mimi itabidi kupitisha mkono wangu katika toupper, ambayo ni karibu sawa; inaonekana karibu kufanana.

480
00:30:54,990 --> 00:31:01,900
Toupper kinachotokea kwa kutumia si operator au bali this guy na df.

481
00:31:01,900 --> 00:31:09,300
Je df kuwakilisha? df? Mtu yeyote? >> [Mwanafunzi] 255.

482
00:31:09,300 --> 00:31:12,780
255? Si 255. Hiyo itakuwa ff.

483
00:31:12,780 --> 00:31:15,210
Tutaweza kuondoka hii moja kama zoezi kidogo.

484
00:31:15,210 --> 00:31:23,460
Lakini kama wewe kwenda kutoka 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 na kisha nini inakuja baada ya 9?

485
00:31:23,460 --> 00:31:26,510
Sisi ni aina ya nje ya tarakimu decimal, lakini katika hexadesimoli kile unakuja baada ya 9?

486
00:31:26,510 --> 00:31:29,510
[Mwanafunzi] a. >> Hivyo, b, c, d.

487
00:31:29,510 --> 00:31:33,470
Unaweza kufikiri kutoka huko nini muundo wa bits d kweli inawakilisha.

488
00:31:33,470 --> 00:31:38,850
Na kama sisi kufanya math, tutaweza kuona kwamba mask wewe kuishia kupata nyuma ni sawa na hii.

489
00:31:38,850 --> 00:31:45,580
Hii ni f, wote 1s, na hii ni d. Hivyo df inawakilisha kwamba mask. Wote haki.

490
00:31:45,580 --> 00:31:50,980
Na mwisho, si kufanya mambo sound super, super kiufundi,

491
00:31:50,980 --> 00:31:53,840
lakini nadhani sisi alitaka kuandika mpango kwamba hana huu.

492
00:31:53,840 --> 00:31:58,960
Hebu kwenda mbele na kufanya binary, ambayo ni programu katika faili inayoitwa binary.c.

493
00:31:58,960 --> 00:32:02,050
Na sasa napenda kukimbia binary na kunipa integer zisizo hasi.

494
00:32:02,050 --> 00:32:03,960
Hebu kuanza rahisi na aina katika 0.

495
00:32:03,960 --> 00:32:09,010
Hii sasa ni mpango kwamba Prints nje integer katika binary uwakilishi wake.

496
00:32:09,010 --> 00:32:13,470
Hivyo kama mimi kucheza mchezo huu tena na aina katika 1 tu, mimi lazima kupata uwakilishi 32-bit ya 1.

497
00:32:13,470 --> 00:32:15,490
Kama mimi kufanya hii tena na 2, mimi lazima kupata hiyo.

498
00:32:15,490 --> 00:32:19,310
Kama mimi kufanya 7, mimi lazima kupata 1s chache mwishoni na kadhalika.

499
00:32:19,310 --> 00:32:22,740
Ni zinageuka mimi kutaja hili kwa sababu pamoja na shughuli bitwise

500
00:32:22,740 --> 00:32:25,490
unaweza kweli kufanya kitu kimoja nyingine pia.

501
00:32:25,490 --> 00:32:29,130
Unaweza kuunda masks haya dynamically.

502
00:32:29,130 --> 00:32:32,800
Kuangalia mfano huu moja ya mwisho ya kuwashirikisha shughuli bitwise.

503
00:32:32,800 --> 00:32:35,490
Hapa ni sehemu ya kwanza ya kificho, na kuchochea mtumiaji kwa idadi,

504
00:32:35,490 --> 00:32:38,130
na anasisitiza kwamba wewe nipe integer zisizo hasi.

505
00:32:38,130 --> 00:32:39,780
Basi hiyo ni aina ya mambo ya kale shule.

506
00:32:39,780 --> 00:32:41,980
Lakini hapa ni kitu ambacho ni aina ya kuvutia.

507
00:32:41,980 --> 00:32:44,910
>> Jinsi gani mimi kwenda kuhusu uchapishaji idadi katika binary?

508
00:32:44,910 --> 00:32:48,970
Mimi kwanza iterate kutoka kile kile?

509
00:32:48,970 --> 00:32:52,270
Nini ukubwa wa int kawaida, angalau katika appliance? >> [Mwanafunzi] 4.

510
00:32:52,270 --> 00:32:57,130
Ni 4. Hivyo 4 * 8 ni 32-1 ni 31.

511
00:32:57,130 --> 00:33:02,590
Basi, ikiwa mimi nina kuanza kuhesabu kutoka 31, kwamba inawakilisha, ni zamu nje,

512
00:33:02,590 --> 00:33:07,630
tu conceptually, kidogo 31 au zaidi kidogo ili, ambayo ni guy hii zaidi ya hapa,

513
00:33:07,630 --> 00:33:09,650
ambapo hii ni kwenda kuwa kidogo 0.

514
00:33:09,650 --> 00:33:12,850
Hivyo hii ni kidogo kidogo ... 01 31.

515
00:33:12,850 --> 00:33:14,950
Hivyo kile ni kanuni hii kufanya?

516
00:33:14,950 --> 00:33:20,140
Taarifa hii kwa kitanzi, ingawa inaonekana cryptic, ni tu iterating kutoka 31 chini ya 0. Hiyo ni.

517
00:33:20,140 --> 00:33:24,530
Hivyo sehemu ya kuvutia sasa lazima katika mistari haya 5 hapa.

518
00:33:24,530 --> 00:33:28,110
Ona kwamba katika mstari huu mimi nina kutangaza variable kuitwa mask

519
00:33:28,110 --> 00:33:30,790
kuwa thabiti na hadithi yetu ya namba hizi njano.

520
00:33:30,790 --> 00:33:32,200
Na kisha nini hii kufanya?

521
00:33:32,200 --> 00:33:35,720
Hii ni nyingine operator bitwise tumekuwa si kuona mbele, uwezekano mkubwa.

522
00:33:35,720 --> 00:33:38,300
Ni kushoto kuhama operator.

523
00:33:38,300 --> 00:33:40,060
Operator Hii haina hii.

524
00:33:40,060 --> 00:33:44,920
Hapa ni namba 1, na kama huna i kushoto kuhama, kushoto kuhama,

525
00:33:44,920 --> 00:33:49,260
nini unafikiri kwamba ina athari ya kufanya kwa 1 kwamba mtu binafsi?

526
00:33:49,260 --> 00:33:51,290
Literally shifting ni juu.

527
00:33:51,290 --> 00:33:57,540
Hivyo kama namba 1 ni nini una upande wa kushoto na kuanza kwa initializing i kwa 31,

528
00:33:57,540 --> 00:34:03,490
kile ni kwamba anaenda kufanya nini? Ni kwenda kuchukua namba 1 na kuhama ni maeneo 31 zaidi ya hapa.

529
00:34:03,490 --> 00:34:06,210
Na kwa sababu kuna wazi hakuna tarakimu nyingine nyuma yake,

530
00:34:06,210 --> 00:34:10,350
hizo na default kubadilishwa na sekunde 0.

531
00:34:10,350 --> 00:34:15,120
Hivyo itabidi kuanza nje na idadi 1, ambayo bila shaka inaonekana kama hii -

532
00:34:15,120 --> 00:34:18,659
na basi mimi kuteka ni zaidi ya hapa katikati.

533
00:34:18,659 --> 00:34:22,139
Na kisha kama wewe kuhama mambo kwa upande wa kushoto, guy hii kimsingi inakwenda kwa njia hii.

534
00:34:22,139 --> 00:34:24,659
Lakini kwa haraka kama wewe kufanya hivyo, 0 anapata kujazwa ndani

535
00:34:24,659 --> 00:34:28,360
Kama wewe kuhama mara ya pili, unaendelea kwa njia hii na mwingine anapata kujazwa 0 in

536
00:34:28,360 --> 00:34:31,000
>> Wewe kuhama tena na kisha 0 mwingine anapata kujazwa ndani

537
00:34:31,000 --> 00:34:37,900
Hivyo kama wewe kufanya jambo hili la << 1 i 31, maeneo, wewe kuishia kupata mask

538
00:34:37,900 --> 00:34:42,550
kwamba ni 32 wahusika muda mrefu, mmoja leftmost ambayo ni 1,

539
00:34:42,550 --> 00:34:45,199
yote ya mapumziko ya ambayo ni 0.

540
00:34:45,199 --> 00:34:50,880
Na zinageuka, kama kando, shifting idadi ya kushoto kama hii

541
00:34:50,880 --> 00:34:53,530
pia kiajali, na wakati mwingine conveniently,

542
00:34:53,530 --> 00:34:57,520
ina athari ya kufanya nini kwa idadi hiyo? >> [Mwanafunzi] kutaka kuongezwa.

543
00:34:57,520 --> 00:35:00,980
Kutaka kuongezwa kwa sababu kila moja ya nguzo - mahali 1s, 2S mahali, 4s mahali,

544
00:35:00,980 --> 00:35:05,030
8s mahali, 16S mahali - they're wote mara dufu kama wewe kwenda kushoto.

545
00:35:05,030 --> 00:35:09,500
Au tuseme, wakati wewe kuhama 1s utaenda kuishia kutaka kuongezwa thamani ya idadi.

546
00:35:09,500 --> 00:35:12,070
Unaweza kuishia kufanya mabadiliko ya kuvutia ya tarakimu

547
00:35:12,070 --> 00:35:15,640
na shifting kila kitu juu kwa namna hii kwa nguvu ya 2.

548
00:35:15,640 --> 00:35:17,150
Hivyo ni jinsi gani kazi hii?

549
00:35:17,150 --> 00:35:22,580
Hii basi anitiaye mask kwamba wote isipokuwa kwa sekunde 0 1 katika mahali just mimi nataka,

550
00:35:22,580 --> 00:35:27,920
na kisha hii kujieleza, ambayo ni kuibiwa kutoka toupper.c,

551
00:35:27,920 --> 00:35:31,770
ni kusema tu kuchukua idadi n kwamba mtumiaji typed katika,

552
00:35:31,770 --> 00:35:34,730
"Na" kwa mask kwamba, na nini ni wewe kwenda kupata?

553
00:35:34,730 --> 00:35:39,200
Wewe ni kwenda kupata 1 kama kuna 1 katika eneo kwamba Masked,

554
00:35:39,200 --> 00:35:41,570
au wewe ni kwenda kupata 0 kama kuna si.

555
00:35:41,570 --> 00:35:44,370
Na hivyo programu hii yote haina ufanisi ni ina kitanzi,

556
00:35:44,370 --> 00:35:48,340
na inajenga mask na 1 zaidi ya hapa, basi 1 zaidi ya hapa, basi 1 zaidi ya hapa,

557
00:35:48,340 --> 00:35:52,950
na inatumia hii bitwise NA hila kusema ni kuna kidogo 1 katika pembejeo ya mtumiaji hapa?

558
00:35:52,950 --> 00:35:59,220
>> Je, kuna kidogo 1 katika pembejeo ya mtumiaji hapa? Na kama hivyo, literally magazeti 1, mwingine magazeti 0.

559
00:35:59,220 --> 00:36:03,780
Sisi ni kufanya hii kwa sababu tu ints kwamba ni kwa nini sisi ni kufanya bits 32 badala ya 8,

560
00:36:03,780 --> 00:36:06,900
lakini kile ambacho tumekuwa kuletwa basi ni hii bitwise NA, AU hii bitwise,

561
00:36:06,900 --> 00:36:10,450
na hii kushoto kuhama operator, ambayo si mara nyingi sana msaada,

562
00:36:10,450 --> 00:36:12,230
lakini zinageuka wanaweza kuwa.

563
00:36:12,230 --> 00:36:16,560
Kwa kweli, kama ungekuwa na kuwakilisha kitu kama safu ya Booleans

564
00:36:16,560 --> 00:36:21,260
tu kuwakilisha kweli au uongo, tuseme alitaka kuweka wimbo wa kama au

565
00:36:21,260 --> 00:36:24,630
chumba kamili ya wanafunzi 300 ni sasa,

566
00:36:24,630 --> 00:36:29,420
unaweza kutangaza safu ya ukubwa 300 ya aina bool ili kupata bools 300,

567
00:36:29,420 --> 00:36:33,090
na unaweza kuweka kila kweli kama mtu ni hapa na uongo vinginevyo.

568
00:36:33,090 --> 00:36:37,550
Kwa nini ni kuwa uwakilishi katika muundo kwamba data ufanisi?

569
00:36:39,370 --> 00:36:44,800
Nini mbaya kuhusu mpango wa kuwa muundo data, safu ya bools 300?

570
00:36:46,190 --> 00:36:49,600
Nini ni bool, kwa kweli, chini ya Hood?

571
00:36:49,600 --> 00:36:52,310
Hii pia, ni kitu ambacho wanaweza kuwa familiar.

572
00:36:52,310 --> 00:36:53,720
Ni zinageuka hakuna bool.

573
00:36:53,720 --> 00:36:56,620
Kumbuka sisi aina ya umba kwamba na faili cs50.h,

574
00:36:56,620 --> 00:36:58,630
ambayo yenyewe ni pamoja bool standard.

575
00:36:58,630 --> 00:37:00,930
C ni aina ya bubu, ingawa, linapokuja bool.

576
00:37:00,930 --> 00:37:04,880
Ni matumizi ya bits 8 kuwakilisha kila bool, ambayo ni kabisa fujo

577
00:37:04,880 --> 00:37:09,040
kwa sababu ni wazi, jinsi wengi bits gani unahitaji kuwakilisha bool? 1 tu.

578
00:37:09,040 --> 00:37:13,190
Hivyo ni zinageuka kuwa kama wewe sasa una uwezo pamoja na waendesha bitwise

579
00:37:13,190 --> 00:37:17,760
kuendesha bits mtu binafsi hata katika Char, hata katika Byte moja,

580
00:37:17,760 --> 00:37:21,380
zinageuka unaweza kupungua kumbukumbu inahitajika kuwakilisha kitu kijinga

581
00:37:21,380 --> 00:37:25,490
kama kwamba mahudhurio styled data muundo kwa sababu ya 8.

582
00:37:25,490 --> 00:37:29,820
Badala ya kutumia bits nane kuwakilisha kweli au uongo, unaweza kutumia moja literally

583
00:37:29,820 --> 00:37:34,500
kwa kutumia Byte moja kwa kila wanafunzi nane katika darasa

584
00:37:34,500 --> 00:37:41,990
na toggling kutoka bits 0-1 mtu binafsi kwa kutumia aina hii ya tricks ngazi ya chini.

585
00:37:43,850 --> 00:37:49,460
Kwamba kwa kweli kukomesha nishati. Je, kuna maswali kuhusu shughuli bitwise?

586
00:37:49,460 --> 00:37:52,710
>> Yeah. >> [Mwanafunzi] Je, kuna operator kipekee au?

587
00:37:52,710 --> 00:37:56,440
Ndiyo. Kuna operator kipekee au kwamba inaonekana kama hii, ^, alama karoti,

588
00:37:56,440 --> 00:38:02,070
ambayo ina maana tu jambo la kwanza au kitu pili inaweza kuwa 1 kwa pato kuwa 1.

589
00:38:02,070 --> 00:38:07,750
Kuna pia si, ~, ambayo itawawezesha Geuza 0 kwa kinyume 1 au makamu pia.

590
00:38:07,750 --> 00:38:11,600
Na pia kuna haki ya kuhama operator, >>, ambayo ni kinyume moja tuliona.

591
00:38:11,600 --> 00:38:13,850
Wote haki. Hebu sasa mambo kwa kiwango cha juu.

592
00:38:13,850 --> 00:38:16,770
Sisi kuanza kwa kuzungumza kuhusu maandishi na kisha compressing ni

593
00:38:16,770 --> 00:38:19,650
na anayewakilisha asilia na idadi chache ya bits;

594
00:38:19,650 --> 00:38:22,890
sisi aliyesema kidogo kuhusu jinsi gani tunaweza sasa kuanza kufanyia mambo katika ngazi bitwise.

595
00:38:22,890 --> 00:38:26,640
Hebu sasa zoom nyuma juu ya miguu 10,000 kwa uwakilishi

596
00:38:26,640 --> 00:38:29,250
mambo magumu zaidi kama graphics.

597
00:38:29,250 --> 00:38:32,950
Hapa tuna bendera ya Ujerumani, hapa tuna moja ya Ufaransa.

598
00:38:32,950 --> 00:38:36,350
Haya yanaweza kuwakilishwa katika format faili unaweza kujua - GIFs, kwa mfano.

599
00:38:36,350 --> 00:38:40,030
Kama ve milele kuonekana picha kwenye mtandao kwamba mwisho katika. Gif,

600
00:38:40,030 --> 00:38:43,000
hii ni interchange graphics format.

601
00:38:43,000 --> 00:38:47,530
Hizi bendera mbili hapa aina ya mikopo wenyewe kwa compression

602
00:38:47,530 --> 00:38:52,050
kwa nini labda dhahiri sababu? >> [Inaudible mwanafunzi majibu]

603
00:38:52,050 --> 00:38:53,440
Kuna mengi ya marudio, haki?

604
00:38:53,440 --> 00:38:57,270
Ili kutuma bendera ya Ujerumani, kufikiri ya hii kama kuwa picha kwenye screen

605
00:38:57,270 --> 00:38:59,030
nyuma katika siku yako Scratch.

606
00:38:59,030 --> 00:39:02,380
Unaweza kukumbuka kwamba kuna mtu au saizi ya dots kwamba compose picha.

607
00:39:02,380 --> 00:39:06,650
>> Kuna mstari mzima wa dots nyeusi na mwingine safu nzima ya dots nyeusi.

608
00:39:06,650 --> 00:39:10,110
Kuna kundi la safu ya dots nyeusi kwamba tunaweza kuona kama kweli sisi zoomed katika,

609
00:39:10,110 --> 00:39:13,370
sana kama wakati sisi zoomed katika juu ya uso Rob katika Photoshop.

610
00:39:13,370 --> 00:39:15,500
Haraka kama sisi got zaidi na zaidi na zaidi katika picha,

611
00:39:15,500 --> 00:39:19,990
wewe kuanza kuona pixelation, wote wa viwanja kuwa linajumuisha jicho lake katika kesi hiyo.

612
00:39:19,990 --> 00:39:24,130
Same mpango hapa. Kama sisi zoomed katika kidogo kabisa, ungependa kuona dots mtu binafsi.

613
00:39:24,130 --> 00:39:27,110
Naam, hii ni aina ya taka ya bits.

614
00:39:27,110 --> 00:39:32,120
Kama tatu wa bendera ni nyeusi na ya tatu ya bendera ni njano na kadhalika,

615
00:39:32,120 --> 00:39:34,860
kwa nini tushindwe kwa namna fulani compress hii bendera?

616
00:39:34,860 --> 00:39:39,560
Na hata bendera Kifaransa inaweza kuwa Komprimerade ingawa muundo ni tofauti kidogo.

617
00:39:39,560 --> 00:39:44,120
Ni zinageuka faili GIF format ni lossless compression format,

618
00:39:44,120 --> 00:39:48,420
ambayo ina maana unaweza kuchukua sura kama bendera ya Ujerumani hapa,

619
00:39:48,420 --> 00:39:53,540
unaweza kutupa mbali mengi ya bits yake bila kutoa sadaka quality.

620
00:39:53,540 --> 00:39:55,340
Hii ni tofauti na kitu kama JPEGs,

621
00:39:55,340 --> 00:39:57,050
ambayo wengi wetu pengine ni zaidi ya ukoo.

622
00:39:57,050 --> 00:39:59,000
Facebook photos na Flickr picha na kama

623
00:39:59,000 --> 00:40:02,200
ni karibu daima kuokolewa kama JPEGs wakati wao ni uploaded,

624
00:40:02,200 --> 00:40:08,100
lakini JPEGs ni lossy - format ambapo huna kutupa bits - LOSSY

625
00:40:08,100 --> 00:40:10,430
lakini wewe pia kutupa quality.

626
00:40:10,430 --> 00:40:13,890
Na hivyo kama wewe compress photos kwa Photoshop au upload yao kwa Facebook

627
00:40:13,890 --> 00:40:15,580
au kuchukua kwenye simu kweli crappy,

628
00:40:15,580 --> 00:40:19,510
unajua kwamba picha ya kuanza kupata sana splotchy na pixelated,

629
00:40:19,510 --> 00:40:22,290
na kwamba kwa sababu ni kuwa Komprimerade na kompyuta au simu

630
00:40:22,290 --> 00:40:24,550
na literally kutupa taarifa mbali.

631
00:40:24,550 --> 00:40:28,500
Lakini GIF ni ajabu kwa kuwa unaweza kutumia bits wachache kuliko nguvu, kwa default

632
00:40:28,500 --> 00:40:30,750
bila ya kupoteza taarifa yoyote.

633
00:40:30,750 --> 00:40:32,410
>> Na kimsingi anafanya hivyo kama ifuatavyo.

634
00:40:32,410 --> 00:40:38,740
Badala ya kuhifadhi katika faili kama BMP ingekuwa mara tatu kwa RGB nyeusi, nyeusi, nyeusi, nyeusi,

635
00:40:38,740 --> 00:40:42,570
nyeusi, nyeusi, nyeusi, nyeusi, nyeusi, nyeusi, nyeusi, nyeusi na kadhalika,

636
00:40:42,570 --> 00:40:45,640
badala yake, format GIF ni kwenda kusema, "Black,"

637
00:40:45,640 --> 00:40:48,330
na kisha, "Rudia hivi mara 100," au kitu kama hicho.

638
00:40:48,330 --> 00:40:52,280
"Black, kurudia mara hii 100, nyeusi, kurudia mara hii 100 ..."

639
00:40:52,280 --> 00:40:54,530
"Yellow, kurudia mara hii 100."

640
00:40:54,530 --> 00:40:57,200
Na hivyo anakumbuka, kimsingi, pixel leftmost

641
00:40:57,200 --> 00:41:02,160
na kisha husimba namna fulani dhana ya kurudia kwamba pixel tena na tena.

642
00:41:02,160 --> 00:41:06,110
Hivyo basi unaweza GIFs compress wenyewe bila ya kupoteza taarifa yoyote.

643
00:41:06,110 --> 00:41:09,510
Lakini kama alikuwa na nadhani, kama kwamba ni algorithm kwamba gifs matumizi,

644
00:41:09,510 --> 00:41:13,180
ambayo ya bendera hizi, ingawa wao kuangalia kufanana katika kawaida,

645
00:41:13,180 --> 00:41:19,620
ni kwenda kuwa ndogo wakati kuokolewa kwenye disk kama GIF? >> [Mwanafunzi] Ujerumani.

646
00:41:19,620 --> 00:41:21,660
Ujerumani ni kwenda kuwa ndogo? Kwa nini?

647
00:41:21,660 --> 00:41:26,620
[Mwanafunzi] Kwa sababu wewe kurudia hivyo wengi, mara nyingi usawa

648
00:41:26,620 --> 00:41:29,010
na kisha wewe kurudia wakati mwingine. >> Hasa.

649
00:41:29,010 --> 00:41:32,020
Kwa sababu watu ambao zuliwa GIF aina tu ya kiholela aliamua

650
00:41:32,020 --> 00:41:36,040
kwamba marudio itakuwa leveraged usawa na si laterally.

651
00:41:36,040 --> 00:41:40,900
Kuna mengi zaidi marudio laterally hapa katika bendera ya Ujerumani kuliko katika bendera ya Kifaransa.

652
00:41:40,900 --> 00:41:44,430
Hivyo kama sisi kweli kufungua folda kwenye gari yangu ngumu ambayo ina GIFs hizi,

653
00:41:44,430 --> 00:41:51,920
unaweza kuona kwamba bendera ya Ujerumani hapa ni 2 kilobytes na moja ni Kifaransa 4 kilobytes.

654
00:41:51,920 --> 00:41:54,080
Hutokea kwa kuwa kwa bahati mbaya kuwa moja ni mara mbili nyingine,

655
00:41:54,080 --> 00:41:57,960
lakini ni kwa kweli kesi hiyo bendera Kifaransa ni kubwa zaidi.

656
00:41:57,960 --> 00:42:01,250
>> Hata ingawa sisi ni kuzungumza hapa kuhusu graphics, mawazo huo unaweza kuomba

657
00:42:01,250 --> 00:42:05,150
si mambo kama bendera lakini picha ambazo ni kidogo ngumu zaidi.

658
00:42:05,150 --> 00:42:08,170
Kama wewe kuchukua picha ya apple, hakika kuna mengi ya kurudia huko,

659
00:42:08,170 --> 00:42:11,040
hivyo tunaweza kukumbuka kwamba kwa namna fulani background default ni bluu

660
00:42:11,040 --> 00:42:13,230
na hivyo, kama picha kulia unaonyesha,

661
00:42:13,230 --> 00:42:16,830
na kukumbuka rangi ya pixel kila moja katika picha hii.

662
00:42:16,830 --> 00:42:21,060
Hivyo tunaweza kutupa bits mbali huko bila ya kupoteza habari.

663
00:42:21,060 --> 00:42:23,340
apple bado inaonekana tu sawa.

664
00:42:23,340 --> 00:42:27,510
Katika mfano huu hapa, unaweza kuona nini kinatokea katika movie.

665
00:42:27,510 --> 00:42:31,970
Hizi kuwakilisha reels filamu zamani-shule ambapo katika picha ya juu kuna

666
00:42:31,970 --> 00:42:36,900
una kuendesha gari RV zamani nyumba na mti.

667
00:42:36,900 --> 00:42:42,130
Na kama kwamba van anatoa nyuma kutoka kushoto kwenda kulia, ni nini wazi si kubadilisha?

668
00:42:42,130 --> 00:42:45,320
nyumba si kwenda popote, na mti si kwenda popote.

669
00:42:45,320 --> 00:42:47,700
Kitu pekee ambacho ni kusonga van katika kesi hii.

670
00:42:47,700 --> 00:42:51,650
Hivyo kama Background Kutobadilika unaonyesha, nini unaweza kufanya katika sinema

671
00:42:51,650 --> 00:42:56,530
ni vile vile tu kutupa taarifa kwamba haina mabadiliko katika kati ya muafaka.

672
00:42:56,530 --> 00:42:58,900
Hii ni kwa ujumla inayojulikana kama compression interframe

673
00:42:58,900 --> 00:43:02,120
ambapo kama frame hii inaonekana karibu kufanana na hii moja,

674
00:43:02,120 --> 00:43:05,390
basi si bother kuhifadhi kwenye disk yoyote ya habari kufanana

675
00:43:05,390 --> 00:43:09,250
juu ya muafaka haya kati, hebu tu kutumia muafaka muhimu mara moja kwa wakati

676
00:43:09,250 --> 00:43:13,420
kwamba kweli kuhifadhi kwamba taarifa redundantly tu kama sanity kidogo kuangalia.

677
00:43:13,420 --> 00:43:18,620
>> Kwa kulinganisha, njia nyingine ya video compressing ni katika mfano huu wa pili na ya chini hapa,

678
00:43:18,620 --> 00:43:23,970
ambapo badala ya kuhifadhi 30 muafaka, kwa nini sio tu kuhifadhi muafaka 15 pili badala yake?

679
00:43:23,970 --> 00:43:27,070
Badala ya aina ya movie inapita uzuri, kikamilifu,

680
00:43:27,070 --> 00:43:30,060
inaweza kuangalia kama ni stuttering kidogo, kidogo umri wa shule,

681
00:43:30,060 --> 00:43:37,190
lakini athari wavu itakuwa kutumia bits mbali wachache kuliko ili vinginevyo kuwa muhimu.

682
00:43:37,190 --> 00:43:39,240
Hivyo ambapo gani hii kisha kuondoka sisi?

683
00:43:39,240 --> 00:43:41,700
Hiyo ilikuwa kidogo ya kando ambapo mwingine unaweza kwenda kwa compression.

684
00:43:41,700 --> 00:43:45,140
Kwa zaidi juu ya kwamba, kuchukua darasa kama CS175 hapa.

685
00:43:45,140 --> 00:43:46,990
Hapa ni mfano mwingine ndani ya video.

686
00:43:46,990 --> 00:43:49,190
Kama nyuki ni kitu tu kusonga,

687
00:43:49,190 --> 00:43:51,790
kweli unaweza kutupa habari katika muafaka wale katikati

688
00:43:51,790 --> 00:43:55,260
kwa sababu ya maua na anga na majani si kubadilisha.

689
00:43:55,260 --> 00:43:57,960
Lakini hebu fikiria sasa moja ya mwisho kitu.

690
00:43:57,960 --> 00:44:03,890
Katika dakika 5 ijayo sisi kuondoka C nyuma ya milele katika hotuba? Ndiyo. Si katika psets, ingawa.

691
00:44:03,890 --> 00:44:10,210
Mwisho hadithi kuhusu C na kisha sisi kupata stuff sexy sana

692
00:44:10,210 --> 00:44:13,870
kuwashirikisha HTML na Mtandao na woo-hoo. Wote haki.

693
00:44:13,870 --> 00:44:16,050
Hapa sisi kwenda. Hiyo ni motisha.

694
00:44:16,050 --> 00:44:20,020
Ni zinageuka wakati huu wote wakati tumekuwa kuandika programu sisi kukimbia Clang.

695
00:44:20,020 --> 00:44:23,890
Na Clang, tumekuwa alisema tangu wiki ya kwanza pretty much, inachukua chanzo code

696
00:44:23,890 --> 00:44:25,740
na waongofu katika kanuni kitu.

697
00:44:25,740 --> 00:44:28,540
Inachukua C na waongofu katika sekunde 0 na 1s.

698
00:44:28,540 --> 00:44:32,150
Nimekuwa aina ya kuwa amelala na wewe kwa muda wa wiki chache kwa sababu si kabisa kama rahisi kama hayo.

699
00:44:32,150 --> 00:44:36,750
>> Kuna mengi zaidi kinachoendelea chini ya Hood wakati kukimbia mpango kama Clang.

700
00:44:36,750 --> 00:44:39,560
Kwa kweli, mchakato wa kuandaa mpango unaweza kweli kuwa muhtasari,

701
00:44:39,560 --> 00:44:42,210
kama unaweza kukumbuka kutoka video Rob juu compilers,

702
00:44:42,210 --> 00:44:47,580
ndani ya hatua hizi 4: kabla ya usindikaji, kuandaa yenyewe, kukusanyika, na kuunganisha.

703
00:44:47,580 --> 00:44:51,950
Lakini sisi katika darasa na watu wengi katika ulimwengu kawaida muhtasari hatua zote hizi

704
00:44:51,950 --> 00:44:54,410
kama tu "kuandaa."

705
00:44:54,410 --> 00:44:58,070
Lakini kama sisi kuanza na chanzo code kama hii, wanakumbuka hili ni rahisi labda C mpango

706
00:44:58,070 --> 00:45:03,530
tumekuwa imeandikwa hivi sasa, kukumbuka kwamba wakati compiled inaishia kuangalia kama hii.

707
00:45:03,530 --> 00:45:07,310
Lakini kuna kweli hatua ya kati, na wale hatua ni kama ifuatavyo.

708
00:45:07,310 --> 00:45:10,750
Kwanza kuna kitu hii ifikapo sana juu ya hili na wengi wa mipango yetu,

709
00:45:10,750 --> 00:45:13,550
# Pamoja <stdio.h>

710
00:45:13,550 --> 00:45:17,210
Je ni pamoja na kufanya # ajili yetu?

711
00:45:17,210 --> 00:45:24,150
Ni pretty much nakala na pastes yaliyomo ndani ya faili stdio.h yangu ili kwamba kwa nini?

712
00:45:24,150 --> 00:45:27,220
Mbona mimi huduma kuhusu yaliyomo ya stdio.h? Nini katika huko wa maslahi?

713
00:45:27,220 --> 00:45:32,310
Tamko Printf wa, mfano wake, ili compiler basi anajua nini namaanisha

714
00:45:32,310 --> 00:45:34,900
wakati mimi kutaja kazi hii printf.

715
00:45:34,900 --> 00:45:39,390
Hivyo hatua ya 1 katika kuandaa ni kabla ya usindikaji, ambapo mpango kama Clang

716
00:45:39,390 --> 00:45:43,450
au baadhi ya mpango msaidizi kwamba Clang kuja na wasomaji code yako juu hadi chini,

717
00:45:43,450 --> 00:45:47,740
kushoto na kulia, na wakati wowote anaona ishara # ikifuatiwa na Keyword kama ni pamoja na,

718
00:45:47,740 --> 00:45:53,980
hufanya kwamba operesheni, kuiga na pasting katika hii stdio.h kesi ndani ya faili yako.

719
00:45:53,980 --> 00:45:55,510
Hiyo ni hatua ya 1.

720
00:45:55,510 --> 00:45:59,620
Kisha una kubwa sana C faili sababu ya nakala kubwa, kuweka kazi hiyo ilitokea tu.

721
00:45:59,620 --> 00:46:01,710
>> Hatua ya 2 sasa ni kuandaa.

722
00:46:01,710 --> 00:46:04,880
Lakini zinageuka kuandaa inachukua chanzo kificho kwamba inaonekana kama hii

723
00:46:04,880 --> 00:46:08,160
na anarudi katika kitu ambacho inaonekana kama hii,

724
00:46:08,160 --> 00:46:12,560
ambayo kwa wale jamaa ni wito? >> [Mwanafunzi] Bunge. >> Baraza lugha.

725
00:46:12,560 --> 00:46:16,700
Hii ni kweli kitu kama wewe kuchukua CS61 utasikia kupiga mbizi katika kwa undani zaidi.

726
00:46:16,700 --> 00:46:22,380
Hii ni kuhusu karibu kama unaweza kupata kwa kuandika sekunde 0 na 1s mwenyewe

727
00:46:22,380 --> 00:46:25,850
lakini kuandika mambo katika njia ambayo bado inafanya angalau kidogo ya akili vile.

728
00:46:25,850 --> 00:46:30,760
Hizi ni mashine ya maelekezo, na kama sisi kitabu chini na kazi kuu hapa,

729
00:46:30,760 --> 00:46:35,470
taarifa kwamba kuna maelekezo haya kushinikiza, hoja mafundisho, Ondoa mafundisho,

730
00:46:35,470 --> 00:46:38,550
piga mafundisho, na kadhalika.

731
00:46:38,550 --> 00:46:42,930
Wakati kusikia kwamba kompyuta yako ina Intel ndani,

732
00:46:42,930 --> 00:46:46,180
una CPU Intel katika Mac au PC yako, nini maana ya kwamba?

733
00:46:46,180 --> 00:46:51,200
CPU huja lililojengwa na makampuni kama Intel kuelewa maelekezo fulani.

734
00:46:51,200 --> 00:46:55,770
Wao hawana wazo nini kazi kama byta ni au kuu ni per se,

735
00:46:55,770 --> 00:47:00,060
lakini wao kujua nini ngazi ya chini sana maelekezo kama kuongeza, Ondoa, kushinikiza,

736
00:47:00,060 --> 00:47:02,430
hoja, piga, na kadhalika ni.

737
00:47:02,430 --> 00:47:06,170
Hivyo wakati wewe kukusanya C code katika lugha mkutano,

738
00:47:06,170 --> 00:47:11,820
user yako sana code kirafiki-kuangalia ni waongofu katika kitu ambacho inaonekana kama hii,

739
00:47:11,820 --> 00:47:21,670
kwamba literally moves ka au ka 4 kuzunguka katika vitengo vile ndogo ndani na nje ya CPU.

740
00:47:21,670 --> 00:47:26,820
Lakini hatimaye, wakati Clang ni tayari kuchukua hii ya uwakilishi wa mpango wako

741
00:47:26,820 --> 00:47:30,940
ndani ya sekunde 0 na 1s, basi hatua inayoitwa kukusanyika kinachotokea,

742
00:47:30,940 --> 00:47:33,850
na hii tena wote hutokea katika kupepesa jicho wakati wa mbio Clang.

743
00:47:33,850 --> 00:47:39,300
Sisi kuanza hapa, ni matokeo ya faili kama hii, na kisha ni waongofu kwa sekunde 0 hizi na 1s.

744
00:47:39,300 --> 00:47:42,000
Na kama unataka kwenda nyuma katika baadhi ya uhakika na kweli kuona hii katika hatua,

745
00:47:42,000 --> 00:47:48,220
kama mimi kwenda katika hello1.c-hii ni moja ya mipango ya kwanza kabisa tuliangalia -

746
00:47:48,220 --> 00:47:53,710
kawaida sisi ingekuwa kukusanya hii kwa hello1.c Clang na hii atatupa a.out.

747
00:47:53,710 --> 00:47:59,890
Kama kwa kulinganisha wewe badala kuwapa-S bendera, nini utapata ni hello1.s

748
00:47:59,890 --> 00:48:02,750
na wewe utakuwa kweli kuona lugha ya mkutano.

749
00:48:02,750 --> 00:48:05,750
>> Mimi nina kufanya hili kwa ajili ya mpango mfupi sana, lakini kama wewe kurudi nyuma kwa kinyang'anyiro

750
00:48:05,750 --> 00:48:08,740
au Kuokoa au na mpango wowote ve imeandikwa tu nje ya udadisi

751
00:48:08,740 --> 00:48:13,240
wanataka kuona nini kweli inaonekana kama, nini kweli kuwa kulishwa ndani ya CPU,

752
00:48:13,240 --> 00:48:15,700
unaweza kutumia kwamba-S bendera na Clang.

753
00:48:15,700 --> 00:48:17,770
Lakini basi mwisho, bado kuna moja gotcha.

754
00:48:17,770 --> 00:48:21,810
Hapa ni sekunde 0 na 1s kwamba kuwakilisha utekelezaji wangu wa hujambo dunia.

755
00:48:21,810 --> 00:48:25,530
Lakini mimi kutumika kazi ya mtu mwingine katika mpango wangu.

756
00:48:25,530 --> 00:48:28,710
Hivyo ingawa mchakato imekuwa mimi kuchukua hello.c,

757
00:48:28,710 --> 00:48:34,280
anapata compiled katika code mkutano, na kisha anapata wamekusanyika ndani ya sekunde 0 na 1s,

758
00:48:34,280 --> 00:48:37,460
tu sekunde 0 na 1s kwamba ni outputted katika hatua hii kwa wakati

759
00:48:37,460 --> 00:48:40,270
ni wale ambao matokeo kutoka code yangu.

760
00:48:40,270 --> 00:48:44,400
Lakini mtu ambaye aliandika printf, wao compiled kanuni zao miaka 20 iliyopita

761
00:48:44,400 --> 00:48:47,000
na ni sasa imewekwa mahali fulani kwenye appliance,

762
00:48:47,000 --> 00:48:51,610
hivyo sisi kwa namna fulani kuwa na kuunganisha sekunde 0 wake au wake na 1s kwa sekunde 0 yangu na 1s,

763
00:48:51,610 --> 00:48:56,160
na kwamba inatuleta hatua 4 na mwisho wa kuandaa, unaojulikana kama kuunganisha.

764
00:48:56,160 --> 00:48:58,680
Hivyo upande wa mkono wa kushoto tuna exact picha kama kabla ya:

765
00:48:58,680 --> 00:49:02,580
hello.c inakuwa mkutano code inakuwa sekunde 0 na 1s.

766
00:49:02,580 --> 00:49:05,960
Lakini kumbuka kwamba mimi kutumika kiwango I / O maktaba katika code yangu,

767
00:49:05,960 --> 00:49:10,350
na kwamba maana mahali fulani kwenye kompyuta kuna faili inayoitwa stdio.c

768
00:49:10,350 --> 00:49:13,980
au angalau version compiled yake kwa sababu mtu baadhi ya miaka iliyopita

769
00:49:13,980 --> 00:49:18,530
compiled stdio.c katika kanuni mkutano na kisha rundo zima la sekunde 0 na 1s.

770
00:49:18,530 --> 00:49:21,130
Hii ni nini inayojulikana kama tuli au maktaba ya nguvu.

771
00:49:21,130 --> 00:49:23,350
Ni baadhi ya faili wamekaa mahali fulani katika appliance.

772
00:49:23,350 --> 00:49:28,710
>> Lakini mwishowe, nina kuchukua sekunde 0 yangu na 1s na kwamba ni mtu sekunde 0 na 1s

773
00:49:28,710 --> 00:49:32,760
na kwa namna fulani kuwaunganisha pamoja, literally kuchanganya wale sekunde 0 na 1s

774
00:49:32,760 --> 00:49:37,900
ndani ya faili moja iitwayo a.out au hello1 au chochote mimi kuitwa mpango wangu

775
00:49:37,900 --> 00:49:43,320
ili matokeo ya mwisho ina wote wa 1s na sekunde 0 kwamba lazima kutunga mpango wangu.

776
00:49:43,320 --> 00:49:45,660
Hivyo wakati huu wote hii muhula wakati tumekuwa kutumia Clang

777
00:49:45,660 --> 00:49:48,750
na hata hivi karibuni zaidi mbio kufanya ili kuendesha Clang,

778
00:49:48,750 --> 00:49:53,580
hatua zote hizi zimekuwa zikijitokeza aina ya mara lakini sana kwa makusudi.

779
00:49:53,580 --> 00:49:57,830
Na hivyo kama wewe kuendelea katika sayansi ya kompyuta, yaani CS61,

780
00:49:57,830 --> 00:50:00,850
hii ni safu kwamba utasikia kuendelea peel nyuma mbali huko

781
00:50:00,850 --> 00:50:06,980
kuzungumza juu ya ufanisi, matokeo ya usalama, na kama ya maelezo haya chini ya kiwango.

782
00:50:06,980 --> 00:50:09,220
Lakini pamoja na kwamba, sisi ni kuhusu kuondoka C nyuma.

783
00:50:09,220 --> 00:50:11,420
Hebu kwenda mbele na kuchukua yetu 5-dakika kuvunja sasa,

784
00:50:11,420 --> 00:50:14,190
na wakati sisi kurudi: Internet.

785
00:50:17,280 --> 00:50:19,170
Wote haki. Sisi ni nyuma.

786
00:50:19,170 --> 00:50:23,590
Sasa tunaanza kuangalia wetu siyo tu katika HTML kwa sababu, kama utaona,

787
00:50:23,590 --> 00:50:26,050
HTML yenyewe ni kweli pretty rahisi

788
00:50:26,050 --> 00:50:29,270
lakini kwa kweli katika programu mtandao kwa ujumla zaidi, mitandao kwa ujumla zaidi,

789
00:50:29,270 --> 00:50:31,770
na jinsi Teknolojia zote hizi kuja pamoja

790
00:50:31,770 --> 00:50:35,400
kuruhusu sisi kujenga mipango kiasi kisasa zaidi atop Internet

791
00:50:35,400 --> 00:50:38,690
kuliko hivi sasa tumekuwa na uwezo wa katika madirisha haya nyeusi na nyeupe.

792
00:50:38,690 --> 00:50:42,140
Hakika, katika hatua hii katika muhula ingawa sisi kutumia kiasi kidogo wakati

793
00:50:42,140 --> 00:50:46,200
juu ya PHP, HTML, CSS, JavaScript, SQL na zaidi,

794
00:50:46,200 --> 00:50:48,480
wanafunzi wengi wanaishia kufanya miradi ya mwisho kwamba ni mtandao msingi

795
00:50:48,480 --> 00:50:51,230
kwa sababu kama utaona, background sasa una katika C

796
00:50:51,230 --> 00:50:54,450
ni mengi sana zinazotumika kwa lugha hizi ngazi ya juu.

797
00:50:54,450 --> 00:50:56,800
>> Na kama wewe kuanza kufikiri juu ya mradi wako wa mwisho,

798
00:50:56,800 --> 00:50:59,940
ambayo, kiasi kama Tatizo Set 0, ambapo walikuwa na moyo

799
00:50:59,940 --> 00:51:02,160
kufanya zaidi kitu chochote cha riba na wewe katika Scratch,

800
00:51:02,160 --> 00:51:05,790
mradi wa mwisho ni nafasi yako kuchukua maarifa yako newfound na savvy na C

801
00:51:05,790 --> 00:51:09,850
au PHP au JavaScript au kama nje kwa spin

802
00:51:09,850 --> 00:51:12,330
na kujenga kipande yako mwenyewe sana ya programu kwa ajili ya dunia ya kuona.

803
00:51:12,330 --> 00:51:17,770
Na uzao wewe na mawazo, tunajua kwamba wewe unaweza kichwa hapa, projects.cs50.net.

804
00:51:17,770 --> 00:51:21,800
Kila mwaka, sisi kukusanya mawazo kutoka Kitivo na wafanyakazi na vikundi mwanafunzi juu ya chuo

805
00:51:21,800 --> 00:51:27,330
tu ya kuwasilisha mawazo yao kwa ajili ya mambo ya kuvutia ambayo inaweza kutatuliwa kwa kutumia kompyuta,

806
00:51:27,330 --> 00:51:29,860
kutumia tovuti, kwa kutumia programu.

807
00:51:29,860 --> 00:51:32,360
Hivyo kama wewe ni zinakabiliwa na kuja na wazo yako mwenyewe,

808
00:51:32,360 --> 00:51:35,790
kwa njia zote kitabu kupitia mawazo kuna kutoka mwaka huu na mwisho.

809
00:51:35,790 --> 00:51:39,990
Ni sawa kikamilifu kukabiliana na mradi ambayo imekuwa kukabiliana kabla.

810
00:51:39,990 --> 00:51:44,540
Tumeona programu nyingi kwa ajili ya kuona hali ya kufulia ya chuo,

811
00:51:44,540 --> 00:51:47,000
wengi Apps kwa navigering ukumbi dining menu,

812
00:51:47,000 --> 00:51:49,540
wengi Apps kwa navigering catalog kozi na kama.

813
00:51:49,540 --> 00:51:53,680
Na hakika, katika hotuba ya baadaye na katika semina ya baadaye,

814
00:51:53,680 --> 00:51:57,750
sisi kuanzisha wewe APIs baadhi hadharani, wote inauzwa

815
00:51:57,750 --> 00:52:02,520
kama vile hapa zinapatikana kutoka CS50 juu ya chuo ili kufikia data

816
00:52:02,520 --> 00:52:04,910
na wanaweza kufanya mambo ya kuvutia na hayo.

817
00:52:04,910 --> 00:52:09,380
Hivyo zaidi katika miradi ya mwisho katika siku chache wakati sisi kutolewa vipimo,

818
00:52:09,380 --> 00:52:12,990
lakini kwa sasa, kujua kwamba unaweza kufanya kazi solo au na marafiki moja au mbili

819
00:52:12,990 --> 00:52:16,010
juu zaidi mradi wowote wa maslahi na wewe.

820
00:52:16,010 --> 00:52:18,080
Internet.

821
00:52:18,080 --> 00:52:22,300
Wewe kwenda mbele na kujiondoa Laptop yako, wewe kwenda facebook.com kwa mara ya kwanza,

822
00:52:22,300 --> 00:52:27,020
wasijazipokea watumiaji katika hivi karibuni, na hit Enter. Nini hasa hutokea?

823
00:52:27,020 --> 00:52:30,150
>> Wakati wewe hit Enter kwenye kompyuta yako, rundo zima la hatua

824
00:52:30,150 --> 00:52:32,600
kuanza aina ya magically kinachotokea.

825
00:52:32,600 --> 00:52:35,960
Hivyo hapa kwenye server kushoto, mtandao kama Facebook ni hapa juu ya haki,

826
00:52:35,960 --> 00:52:42,500
na kwa namna fulani unatumia hii lugha inayoitwa HTTP, HyperText Transfer itifaki.

827
00:52:42,500 --> 00:52:46,770
HTTP ni si lugha ya programu. Ni zaidi ya itifaki.

828
00:52:46,770 --> 00:52:52,310
Ni seti ya mikataba ya kwamba mtandao browsers na servrar mtandao kutumia wakati intercommunicating.

829
00:52:52,310 --> 00:52:54,360
Na nini maana ya hii ni kama ifuatavyo.

830
00:52:54,360 --> 00:52:56,790
Mengi kama katika ulimwengu wa kweli, tuna mikataba haya

831
00:52:56,790 --> 00:53:00,140
ambapo kama wewe kukutana na baadhi ya binadamu kwa mara ya kwanza, kama huna akili humoring yangu hapa,

832
00:53:00,140 --> 00:53:03,980
Nipate kuja kwenu, kusema, "Hi, jina langu ni David." >> Hi, Daudi. Jina langu ni Sammy.

833
00:53:03,980 --> 00:53:05,770
"Hi, Daudi. Jina langu ni Sammy."

834
00:53:05,770 --> 00:53:08,310
Hivyo sasa sisi tu kushiriki katika aina hii ya itifaki silly binadamu

835
00:53:08,310 --> 00:53:12,200
ambapo mimi wameanzisha itifaki, Sammy ina alijibu,

836
00:53:12,200 --> 00:53:15,060
tumekuwa unaotikiswa mikono, na manunuzi ni kamili.

837
00:53:15,060 --> 00:53:18,260
HTTP ni sawa sana katika roho.

838
00:53:18,260 --> 00:53:23,350
Wakati mtandao wako browser maombi www.facebook.com,

839
00:53:23,350 --> 00:53:27,020
nini browser yako ni kweli kufanya ni kupanua mkono wake, ili kuzungumza,

840
00:53:27,020 --> 00:53:29,960
server na ni kupeleka ujumbe.

841
00:53:29,960 --> 00:53:34,220
Na ujumbe kuwa ni kawaida kitu kama kupata - unataka nini ili kupata? -

842
00:53:34,220 --> 00:53:38,740
kupata yangu ukurasa wa nyumbani, ambayo ni kawaida ulionyehsa kwa kufyeka moja katika mwisho wa URL.

843
00:53:38,740 --> 00:53:43,790
Na hivyo tu kujua nini lugha nina kuzungumza, mimi browser naenda kukuambia

844
00:53:43,790 --> 00:53:46,930
kwamba mimi nina akizungumza HTTP version 1.1,

845
00:53:46,930 --> 00:53:51,980
Na pia kwa hatua nzuri, mimi naenda kukuambia kwamba jeshi kwamba mimi nataka ukurasa wa nyumbani wa

846
00:53:51,980 --> 00:53:54,120
ni facebook.com.

847
00:53:54,120 --> 00:53:57,730
Kawaida, kivinjari, unbeknownst na wewe, mwanadamu,

848
00:53:57,730 --> 00:54:03,350
hutuma ujumbe huu katika mtandao wakati wewe tu aina www.facebook.com,

849
00:54:03,350 --> 00:54:05,370
>> Kuingia, katika browser yako.

850
00:54:05,370 --> 00:54:07,300
Na nini Facebook kujibu kwa?

851
00:54:07,300 --> 00:54:12,540
Ni anajibu na baadhi ya maelezo sawa-kuangalia cryptic lakini pia mengi zaidi.

852
00:54:12,540 --> 00:54:14,310
Hebu kwenda mbele nyumbani ukurasa wa Facebook hapa.

853
00:54:14,310 --> 00:54:17,480
Hii ni screen kwamba wengi wetu pengine kamwe kuona kama wewe kukaa watumiaji katika muda wote,

854
00:54:17,480 --> 00:54:19,830
lakini hii ni kweli nyumba zao ukurasa.

855
00:54:19,830 --> 00:54:24,150
Kama sisi kufanya hili katika Chrome, taarifa kwamba unaweza kuvuta up haya menus muktadha kidogo.

856
00:54:24,150 --> 00:54:26,980
Kutumia Chrome, iwe juu Mac OS, Windows, Linux, au kama,

857
00:54:26,980 --> 00:54:31,840
kama wewe Udhibiti click au click kushoto, unaweza kawaida kuvuta up menu kwamba inaonekana kama hii,

858
00:54:31,840 --> 00:54:35,870
ambapo chaguzi chache wakisubiri, moja ambayo ni View Kwanza Chanzo.

859
00:54:35,870 --> 00:54:39,920
Unaweza pia kawaida kupata mambo haya kwa kwenda menu View na poking kote.

860
00:54:39,920 --> 00:54:42,750
Kwa mfano, hapa chini View, Developer ni kitu kimoja.

861
00:54:42,750 --> 00:54:45,780
Mimi nina kwenda mbele na kuangalia View Chanzo Kwanza.

862
00:54:45,780 --> 00:54:50,800
Nini utaona ni HTML kwamba Marko ameandika kuwakilisha facebook.com.

863
00:54:50,800 --> 00:54:55,910
Ni fujo kamili hapa, lakini tutaweza kuona kwamba hii hufanya kidogo maana zaidi kabla ya muda mrefu.

864
00:54:55,910 --> 00:54:59,840
Lakini kuna baadhi ya mifumo hapa. Hebu kitabu chini stuff kama hii.

865
00:54:59,840 --> 00:55:05,730
Hii ni ngumu kwa binadamu kusoma, lakini taarifa kwamba kuna muundo huu wa mabano angled

866
00:55:05,730 --> 00:55:10,360
na maneno kama chaguo, maneno kama thamani, masharti baadhi alinukuliwa.

867
00:55:10,360 --> 00:55:15,660
Hii ni wapi, wakati saini up kwa mara ya kwanza, maalum kile yako ya kuzaliwa ni mwaka.

868
00:55:15,660 --> 00:55:19,020
Menyu kunjuzi ya miaka ya kuzaliwa kwa namna fulani encoded hapa

869
00:55:19,020 --> 00:55:23,870
katika hii lugha inayoitwa HTML, HyperText Markup lugha.

870
00:55:23,870 --> 00:55:27,730
Kwa maneno mengine, wakati browser yako maombi ya ukurasa wa mtandao,

871
00:55:27,730 --> 00:55:30,610
inazungumzia hii mkataba kuitwa HTTP.

872
00:55:30,610 --> 00:55:35,170
Lakini ni nini facebook.com kujibu ombi kwamba pamoja na?

873
00:55:35,170 --> 00:55:38,260
>> Ni anajibu na baadhi ya ujumbe huu cryptic, kama tutaweza kuona katika wakati huu.

874
00:55:38,260 --> 00:55:43,760
Lakini zaidi ya majibu yake ni katika aina ya HTML, HyperText Markup lugha.

875
00:55:43,760 --> 00:55:47,170
Hiyo ni lugha halisi ambayo ukurasa mtandao yaliyoandikwa.

876
00:55:47,170 --> 00:55:52,030
Na nini kivinjari kweli haina kisha ni, juu ya ofisi ya kitu ambacho inaonekana kama hii,

877
00:55:52,030 --> 00:55:57,120
husoma juu hadi chini, kushoto na kulia, na wakati wowote anaona moja ya mabano haya angled

878
00:55:57,120 --> 00:56:03,370
ikifuatiwa na Keyword kama chaguo, ni maonyesho ya kwamba lugha ghafi katika njia sahihi.

879
00:56:03,370 --> 00:56:06,820
Katika kesi hii, itakuwa kuonyesha drop-down menu ya miaka.

880
00:56:06,820 --> 00:56:09,240
Lakini tena, hii ni fujo kamili ya kuangalia.

881
00:56:09,240 --> 00:56:16,630
Hii ni kwa sababu si Facebook watengenezaji yatangaza 0 5 kwa ajili ya mtindo, kwa mfano.

882
00:56:16,630 --> 00:56:20,190
Hii ni kwa sababu wengi wa kificho kwamba wao kuandika ni, kwa kweli, imeandikwa uzuri,

883
00:56:20,190 --> 00:56:22,450
vizuri maoni, nicely indented, na kama,

884
00:56:22,450 --> 00:56:26,080
lakini wa mashine ya shaka, kompyuta, browsers kweli si kutoa damn

885
00:56:26,080 --> 00:56:27,890
kama code yako ni vizuri-styled.

886
00:56:27,890 --> 00:56:33,100
Na kwa kweli, ni kabisa fujo kwa hit muhimu tab wale mara zote

887
00:56:33,100 --> 00:56:37,650
na kuweka maoni yote katika code yako na kuchagua kweli maelezo majina variable

888
00:56:37,650 --> 00:56:42,340
kwa sababu kama browser hajali, kila unachokifanya mwisho wa siku ni kupoteza bytes.

889
00:56:42,340 --> 00:56:46,660
>> Hivyo zinageuka kile wengi tovuti kufanya ni hata kama chanzo code kwa facebook.com,

890
00:56:46,660 --> 00:56:49,550
kwa cs50.net na wote wa tovuti hizo nyingine kwenye mtandao

891
00:56:49,550 --> 00:56:53,730
ni kawaida vizuri imeandikwa na vizuri maoni na nicely indented na kama,

892
00:56:53,730 --> 00:56:59,270
kawaida kabla ya tovuti ni kuweka kwenye mtandao, code ni minified,

893
00:56:59,270 --> 00:57:02,970
ambapo HTML na CSS - kitu kingine tutaweza kuona hivi karibuni -

894
00:57:02,970 --> 00:57:05,960
Code JavaScript tutaweza kuona hivi karibuni inasukumwa,

895
00:57:05,960 --> 00:57:09,250
ambapo kwa muda mrefu majina variable kuwa X na Y na Z,

896
00:57:09,250 --> 00:57:13,900
na yote ya kwamba whitespace kwamba inafanya kila kitu ili kuangalia ni someka wote kutupwa mbali,

897
00:57:13,900 --> 00:57:17,700
kwa sababu kama wewe kufikiri juu yake kwa njia hii, Facebook anapata ukurasa bilioni hits siku -

898
00:57:17,700 --> 00:57:21,670
kitu mambo kama hayo - hivyo nini kama programu tu kuwa anal

899
00:57:21,670 --> 00:57:26,660
hit bar nafasi moja ya ziada wakati tu Indent baadhi mstari wa kanuni milele hivyo zaidi?

900
00:57:26,660 --> 00:57:29,500
Nini maana kama Facebook huhifadhi kwamba whitespace

901
00:57:29,500 --> 00:57:32,880
katika yote ya ka wao kutuma nyuma kwa watu juu ya mtandao?

902
00:57:32,880 --> 00:57:36,400
Kupiga nafasi bar mara moja inakupa Byte ziada katika faili yako.

903
00:57:36,400 --> 00:57:39,730
Na kama watu bilioni kisha kuendelea na kupakua ukurasa wa nyumbani siku hiyo,

904
00:57:39,730 --> 00:57:42,060
kiasi gani zaidi data kuwa wewe zinaa juu ya mtandao?

905
00:57:42,060 --> 00:57:45,200
gigabyte kwa sababu si nzuri.

906
00:57:45,200 --> 00:57:48,510
Na nafasi, kwa mengi ya Nje hii si suala vile scalable,

907
00:57:48,510 --> 00:57:51,030
lakini kwa Facebook, kwa ajili ya Google, kwa baadhi ya tovuti maarufu zaidi

908
00:57:51,030 --> 00:57:54,860
kuna motisha kubwa kifedha kufanya code yako kuangalia kama fujo

909
00:57:54,860 --> 00:57:58,980
hivyo kwamba wewe ni kutumia kama ka machache iwezekanavyo kwa kuongeza kisha compressing ni

910
00:57:58,980 --> 00:58:01,500
kutumia kitu kama zip, algorithm kuitwa gzip,

911
00:58:01,500 --> 00:58:04,250
kwamba browser gani kwa ajili ya wewe moja kwa moja. Lakini hii ni kubwa.

912
00:58:04,250 --> 00:58:08,060
Hatutawahi kujifunza chochote kuhusu tovuti za watu wengine na jinsi ya kubuni mtandao kurasa

913
00:58:08,060 --> 00:58:09,680
kama tuna kuangalia ni kama hii.

914
00:58:09,680 --> 00:58:13,620
>> Hivyo bahati nzuri, kama browsers Chrome na IE na Firefox siku hizi

915
00:58:13,620 --> 00:58:16,450
kawaida kuja na zana developer kujengwa katika.

916
00:58:16,450 --> 00:58:21,730
Kwa kweli, kama mimi kwenda chini hapa Kagua Element au kama mimi kwenda View, Developer,

917
00:58:21,730 --> 00:58:25,220
na kwenda Vyombo vya Developer waziwazi,

918
00:58:25,220 --> 00:58:27,640
dirisha hili chini ya screen yangu sasa pops up.

919
00:58:27,640 --> 00:58:31,230
Ni kidogo vitisho kwa sababu kwanza kuna mengi ya tabo unfamiliar hapa,

920
00:58:31,230 --> 00:58:34,510
lakini kama mimi bonyeza Elements njia yote katika kushoto chini,

921
00:58:34,510 --> 00:58:38,810
Chrome ni wazi pretty smart. Ni anajua jinsi ya kutafsiri yote ya kanuni hii.

922
00:58:38,810 --> 00:58:42,320
Na hivyo kile Chrome gani ni safisha up wote wa HTML Facebook.

923
00:58:42,320 --> 00:58:45,680
Hata ingawa sio whitespace huko, kuna si indentation huko,

924
00:58:45,680 --> 00:58:51,120
sasa ona kwamba naweza kuanza navigate ukurasa huu mtandao wote zaidi hierarchically.

925
00:58:51,120 --> 00:58:56,910
Ni zinageuka kuwa kila ukurasa wa mtandao yaliyoandikwa katika lugha inayoitwa HTML5 lazima kuanza na hii,

926
00:58:56,910 --> 00:59:03,980
tamko hili DOCTYPE, hivyo kusema: <! DOCTYPE html>

927
00:59:03,980 --> 00:59:07,840
Ni aina ya mwanga na kijivu huko, lakini hiyo ni mstari wa kwanza kabisa wa kificho katika faili hili,

928
00:59:07,840 --> 00:59:12,080
na kwamba tu anamwambia browser, "Hey, inakuja baadhi HTML5 inakuja ukurasa wa mtandao.".

929
00:59:12,080 --> 00:59:18,490
kwanza wazi bracket zaidi ya kuwa hutokea kwa kuwa jambo hili, wazi bracket HTML tag,

930
00:59:18,490 --> 00:59:22,320
na kisha kama mimi kupiga mbizi katika undani - haya ni mishale kabisa maana;

931
00:59:22,320 --> 00:59:25,140
wao ni kwa ajili tu ya uwasilishaji wa, wao si kweli katika faili -

932
00:59:25,140 --> 00:59:30,300
taarifa kwamba ndani ya tag Facebook HTML, chochote huanza na bracket wazi

933
00:59:30,300 --> 00:59:32,910
na kisha ina neno inaitwa tag.

934
00:59:32,910 --> 00:59:38,610
Hivyo ndani tag HTML ni inaonekana tag kichwa na tag mwili.

935
00:59:38,610 --> 00:59:41,930
Ndani ya tag kichwa sasa ni fujo nzima kwa ajili ya Facebook

936
00:59:41,930 --> 00:59:45,620
kwa sababu wana mengi ya metadata na mambo mengine kwa ajili ya masoko na matangazo.

937
00:59:45,620 --> 00:59:50,600
>> Lakini kama sisi kitabu chini, chini, chini, chini, hebu angalia ambapo ni. Hapa ni.

938
00:59:50,600 --> 00:59:52,210
Hii ni moja angalau kiasi fulani familiar.

939
00:59:52,210 --> 00:59:55,990
hatimiliki ya nyumbani ukurasa wa Facebook, kama umewahi kuangalia katika tab katika cheo bar yako,

940
00:59:55,990 --> 00:59:59,060
ni Karibu Facebook - Ingia, Jiandikishe au Jifunze Zaidi.

941
00:59:59,060 --> 01:00:01,110
Hiyo ni nini ungependa kuona katika cheo bar Chrome,

942
01:00:01,110 --> 01:00:03,100
na kwamba ni jinsi gani kuwakilishwa katika code.

943
01:00:03,100 --> 01:00:08,090
Kama sisi kupuuza kila kitu kingine katika kichwa, wengi wa guts ya ukurasa wa mtandao ni katika mwili,

944
01:00:08,090 --> 01:00:10,940
na zinageuka kuwa code Facebook ni kwenda kuangalia zaidi tata

945
01:00:10,940 --> 01:00:14,540
kuliko wengi mambo tutaweza kuandika awali kwa sababu tu ni kuwa kujengwa kwa miaka,

946
01:00:14,540 --> 01:00:17,260
lakini kuna mengi yote ya tags script, JavaScript code,

947
01:00:17,260 --> 01:00:18,870
kwamba inafanya tovuti sana maingiliano:

948
01:00:18,870 --> 01:00:22,330
kuona updates hadhi mara kwa kutumia lugha kama JavaScript.

949
01:00:22,330 --> 01:00:25,270
Kuna kitu kinachoitwa div, ambayo ni zamu ya ukurasa.

950
01:00:25,270 --> 01:00:27,940
Lakini kabla ya sisi kupata undani kwamba, hebu jaribu kwa zoom nje

951
01:00:27,940 --> 01:00:31,920
na kuangalia toleo rahisi ya Facebook 1.0, hivyo kusema.

952
01:00:31,920 --> 01:00:34,740
Hapa ni hello, dunia ya kurasa za mtandao.

953
01:00:34,740 --> 01:00:37,370
Ina kuwa tamko DOCTYPE saa ya juu sana

954
01:00:37,370 --> 01:00:40,280
ambayo ni tofauti kidogo kutoka kila kitu kingine.

955
01:00:40,280 --> 01:00:46,130
Hakuna kitu kingine chochote sisi kuandika katika ukurasa wa mtandao ni kwenda kuanza na <! ila mstari kwamba kuna

956
01:00:46,130 --> 01:00:48,880
na isipokuwa kwa kitu kinachoitwa maoni katika HTML.

957
01:00:48,880 --> 01:00:53,000
Lakini kwa sehemu kubwa, kila kitu katika ukurasa wa mtandao ni wazi bracket, Keyword, karibu bracket.

958
01:00:53,000 --> 01:00:56,220
>> Katika kesi hii unaweza kuona rahisi ya kurasa za mtandao iwezekanavyo.

959
01:00:56,220 --> 01:01:00,260
Tag HTML ina tag kichwa na ina tag mwili,

960
01:01:00,260 --> 01:01:04,580
lakini taarifa kwamba kuna wazo hili la kuanzia na kuacha tags.

961
01:01:04,580 --> 01:01:11,360
Hii ni tag kuanza kwa HTML, hii ni karibu au tag tag mwisho.

962
01:01:11,360 --> 01:01:15,400
Ona kwamba wao ni aina ya kinyume katika maana ya kwamba tag karibu au tag mwisho

963
01:01:15,400 --> 01:01:20,030
ina hii mbele kufyeka ndani ya yenyewe.

964
01:01:20,030 --> 01:01:23,540
Wakati huo huo, kuna wazi kichwa tag hapa na karibu tag kichwa hapa.

965
01:01:23,540 --> 01:01:26,880
>> Kuna cheo wazi na karibu tag cheo hapa.

966
01:01:26,880 --> 01:01:29,850
ukweli kwamba mimi ve kuweka cheo juu ya mstari mmoja, rena holela.

967
01:01:29,850 --> 01:01:33,760
Ni tu inaonekana kama ingekuwa nicely fit kwenye mstari mmoja, hivyo mimi haikujali kupiga Ingiza mara kadhaa.

968
01:01:33,760 --> 01:01:38,200
Wakati huo huo, mwili sikuwa Indent tu kuwa milele hivyo wazi.

969
01:01:38,200 --> 01:01:41,050
Ona kwamba HTML ni lugha pretty bubu.

970
01:01:41,050 --> 01:01:43,410
Kwa kweli, nyuma katika siku kabla kulikuwa WYSIWYG wahariri

971
01:01:43,410 --> 01:01:46,770
na Microsoft Word ambapo unaweza kusema, "Fanya huu ujasiri, italics kufanya hili,"

972
01:01:46,770 --> 01:01:50,850
wewe ingekuwa kweli aina amri kidogo katika insha 20 + miaka iliyopita

973
01:01:50,850 --> 01:01:55,740
ambapo wewe kusema, "Anza kufanya Nakala hii koze Acha kufanya Nakala hii koze.".

974
01:01:55,740 --> 01:01:59,010
"Kuanza kufanya italics hii Nakala Acha kufanya italics hii maandishi.".

975
01:01:59,010 --> 01:02:01,850
>> Hiyo ni nini HTML au lugha yoyote ya kuashiria ni.

976
01:02:01,850 --> 01:02:05,530
Hii tag kwanza anasema, "Hey, browser. Inakuja baadhi HTML."

977
01:02:05,530 --> 01:02:09,880
tag ijayo anasema, "Hey, browser. inakuja kichwa, header wa mtandao ukurasa wangu."

978
01:02:09,880 --> 01:02:11,650
"Hey, browser. Inakuja cheo."

979
01:02:11,650 --> 01:02:15,880
Na kisha zaidi ya hapa, "Hey, browser. Hiyo ni kwa cheo."

980
01:02:15,880 --> 01:02:20,000
Hivyo hii ni jinsi browser anajua tena kuonyesha wahusika zaidi ya hello, dunia

981
01:02:20,000 --> 01:02:21,860
katika title bar.

982
01:02:21,860 --> 01:02:23,640
Wakati huo huo, hii anasema, "Hiyo ni kwa kichwa."

983
01:02:23,640 --> 01:02:28,340
Hii inasema, "Hiyo inakuja mwili Hapa ni mwili halisi." - Literally, maneno hello, ulimwengu.

984
01:02:28,340 --> 01:02:33,190
Na hii anasema hapa, "Hiyo ni kwa ajili ya mwili Hiyo ni kwa HTML.".

985
01:02:33,190 --> 01:02:34,640
Hivyo browsers ni pretty bubu.

986
01:02:34,640 --> 01:02:39,920
Wao tu kusoma hii mambo juu hadi chini, kushoto na kulia, na kufanya nini hasa wanaambiwa kufanya.

987
01:02:39,920 --> 01:02:41,860
Hebu kweli kufanya mfano kidogo hapa.

988
01:02:41,860 --> 01:02:46,240
Hebu kufungua rahisi ya programu juu ya Mac yangu hapa, yaani TextEdit.

989
01:02:46,240 --> 01:02:48,220
On Windows unaweza kutumia Notepad.exe.

990
01:02:48,220 --> 01:02:50,520
Lakini haya ni yote unahitaji kuanza kufanya kurasa za mtandao.

991
01:02:50,520 --> 01:02:53,730
Mimi nina kwenda mbele na nakala tu na kuweka hii code katika faili hii.

992
01:02:53,730 --> 01:02:57,210
Mimi nina kwenda mbele na kuokoa ni kwenye desktop yangu,

993
01:02:57,210 --> 01:03:01,220
na mimi nina kwenda kuokoa hii kama hello.html,

994
01:03:01,220 --> 01:03:03,840
na sasa faili ni jina hello.html.

995
01:03:03,840 --> 01:03:05,690
Hapa ni kwenye desktop yangu.

996
01:03:05,690 --> 01:03:11,130
Hebu sasa kwenda katika browser na Drag faili katika browser.

997
01:03:11,130 --> 01:03:14,060
Na voilà, hapa ni mtandao yangu ya kwanza kabisa ya ukurasa.

998
01:03:14,060 --> 01:03:17,340
Ona kwamba jina la tab ni hello, dunia kama kwa tag cheo,

999
01:03:17,340 --> 01:03:20,040
na taarifa kwamba hello, dunia ni mwili wa mtandao ukurasa wangu,

1000
01:03:20,040 --> 01:03:22,190
na woo-hoo, mimi niko kwenye mtandao.

1001
01:03:22,190 --> 01:03:24,700
>> Mimi si kweli, haki, kwa sababu faili hii si kwenye mtandao.

1002
01:03:24,700 --> 01:03:28,330
Hutokea kwa kuwa kwenye gari yangu mitaa bidii katika kwamba njia fulani.

1003
01:03:28,330 --> 01:03:32,720
Lakini wazo ni sawa. Wote sisi sasa haja ni server mtandao ambayo kwa upload.

1004
01:03:32,720 --> 01:03:37,410
Lakini kwanza hebu kweli kuanzisha kidogo zaidi utata na zaidi kidogo stylization.

1005
01:03:37,410 --> 01:03:39,890
Hii ni rahisi, kama boring, mtandao ukurasa.

1006
01:03:39,890 --> 01:03:41,990
Ni zinageuka kuna aina nyingine ya vitambulisho tunaweza kutumia.

1007
01:03:41,990 --> 01:03:45,530
Kwa mfano, hapa katika njano nimekuwa ilianzisha 2 tags mpya.

1008
01:03:45,530 --> 01:03:49,630
Sisi si kucheza sana na leo hii, lakini taarifa kwamba tag kiungo

1009
01:03:49,630 --> 01:03:52,520
namna fulani inaonekana tofauti na kila kitu kingine.

1010
01:03:52,520 --> 01:03:55,370
tag kiungo inachukua kile kinachojulikana sifa,

1011
01:03:55,370 --> 01:03:59,770
na sifa ni kitu ambacho hugeuza tabia ya tag.

1012
01:03:59,770 --> 01:04:03,840
Katika kesi hii hii si chaguo bora ya majina, kiungo, kwa sababu ni aina ya maana,

1013
01:04:03,840 --> 01:04:11,590
lakini hii tag kiungo anasema, kimsingi, ni pamoja na faili inayoitwa styles.css ndani ya mtandao ukurasa wangu.

1014
01:04:11,590 --> 01:04:15,400
Unaweza kufikiri ya hii kama sawa na C ya # ni pamoja na maelekezo.

1015
01:04:15,400 --> 01:04:19,650
Styles.css ni akimaanisha lugha tofauti kabisa kwamba sisi si kucheza kwa leo,

1016
01:04:19,650 --> 01:04:23,790
lakini ni kwa aesthetics: font ukubwa, rangi, padding, indentation, gharama za uzalishaji,

1017
01:04:23,790 --> 01:04:26,040
na wote wa aina hiyo ya undani aesthetics.

1018
01:04:26,040 --> 01:04:28,820
Wakati huo huo, tag script ni functionally sawa,

1019
01:04:28,820 --> 01:04:33,140
lakini badala ya ni pamoja na CSS, kwamba lugha, ni pamoja na lugha nyingine, JavaScript.

1020
01:04:33,140 --> 01:04:37,810
Hivyo kwa maneno mengine, na vitambulisho hizi 2 mimi hatimaye kuwa na uwezo wa kuandika mtandao wangu mwenyewe ukurasa

1021
01:04:37,810 --> 01:04:41,490
lakini pia kuvuta katika kificho kwamba mimi au mtu mwingine ameandika

1022
01:04:41,490 --> 01:04:44,350
ili tuweze kusimama juu ya mabega ya watu wengine, tunaweza mazoezi ya design nzuri,

1023
01:04:44,350 --> 01:04:46,120
factoring nje code ya kawaida.

1024
01:04:46,120 --> 01:04:49,090
Kama mimi nimepata 10 kurasa za mtandao tofauti, hii ina maana kwamba baadhi ya aesthetics yangu

1025
01:04:49,090 --> 01:04:52,490
inaweza kuwa zitawekwa nje, kiasi kama # ni pamoja na, ndani ya faili tofauti.

1026
01:04:52,490 --> 01:04:54,420
Hivyo sisi ni kupata huko.

1027
01:04:54,420 --> 01:04:57,180
Lakini hebu kweli kwanza kufanya kitu zaidi ya kuvutia na faili hii.

1028
01:04:57,180 --> 01:05:01,110
>> Tena, hii ni tu TextEdit. Mimi si kitaalam juu ya Internet bado, lakini tutaweza kupata huko.

1029
01:05:01,110 --> 01:05:04,910
Ningependa kufanya hello, ulimwengu kidogo bolder kuliko ilivyo.

1030
01:05:04,910 --> 01:05:10,890
Hivyo hello, hebu kiholela kusema <b> kwa ujasiri.

1031
01:05:10,890 --> 01:05:15,910
Tena, hadithi ni sawa: hello, comma, kuanza kufanya hii ujasiri,

1032
01:05:15,910 --> 01:05:19,730
basi dunia anapata kuchapishwa katika ujasiri, na hii ina maana kuacha uchapishaji hii koze.

1033
01:05:19,730 --> 01:05:24,020
Hebu kwenda mbele na kuokoa faili yangu, kurudi nyuma na Chrome, mimi itabidi zoom katika tu ili tuweze kuona ni bora zaidi,

1034
01:05:24,020 --> 01:05:27,870
na Reload, na utaona dunia kwamba ni sasa katika koze.

1035
01:05:27,870 --> 01:05:31,810
Mtandao ni wote kuhusu viungo, hivyo hebu kwenda mbele na kufanya hili:

1036
01:05:31,810 --> 01:05:38,550
tovuti yangu favorite ni, hebu sema, youtube.com.

1037
01:05:38,550 --> 01:05:43,810
Ila, Reload. Sawa. Kuna matatizo ya wanandoa sasa badala hideousness wa tovuti.

1038
01:05:43,810 --> 01:05:47,310
1, nina uhakika pretty mimi hit Enter hapa. Na mimi.

1039
01:05:47,310 --> 01:05:51,590
Mimi si tu hit Enter, mimi pia indented, kufanya mazoezi nini tumekuwa kuhubiri kuhusu mtindo,

1040
01:05:51,590 --> 01:05:54,930
lakini yangu ni haki ya karibu na ulimwengu.

1041
01:05:54,930 --> 01:05:58,410
Hivyo kwa nini hii? Browsers kufanya kile tu wewe kuwaambia cha kufanya.

1042
01:05:58,410 --> 01:06:04,010
Sikumwambia browser, "Break mistari hapa Ingiza. Aya kuvunja hapa."

1043
01:06:04,010 --> 01:06:07,820
Hivyo browser, haijalishi kama mimi hit Kurudi mara 30,

1044
01:06:07,820 --> 01:06:10,820
ni bado kwenda kuweka sahihi yangu ijayo kwa ulimwengu.

1045
01:06:10,820 --> 01:06:15,930
Nini mimi kwa kweli kufanya hapa ni kusema kitu kama <br/>, ingiza kuvunja line.

1046
01:06:15,930 --> 01:06:17,940
>> Na kweli, kuvunja line ni aina ya kitu weird

1047
01:06:17,940 --> 01:06:21,650
sababu huwezi kweli kuanza kuhamia mstari mwingine, kisha kufanya kitu,

1048
01:06:21,650 --> 01:06:25,380
na kisha kuacha kuhamia mstari mpya. Ni aina ya operesheni atomic.

1049
01:06:25,380 --> 01:06:28,140
Wewe ama kufanya hivyo au haujui. Wewe hit Enter au huna.

1050
01:06:28,140 --> 01:06:33,390
Hivyo br ni kidogo kidogo ya tag tofauti, na hivyo mimi unahitaji aina ya wote wazi na karibu ni

1051
01:06:33,390 --> 01:06:35,230
wote kwa mara moja.

1052
01:06:35,230 --> 01:06:37,500
syntax kwa kuwa ni hii.

1053
01:06:37,500 --> 01:06:41,760
Kitaalam, unaweza kufanya kitu kama hiki katika matoleo baadhi ya HTML,

1054
01:06:41,760 --> 01:06:45,600
lakini hii ni wajinga tu kwa sababu hakuna sababu ya kuanza na kuacha kitu

1055
01:06:45,600 --> 01:06:48,420
kama unaweza kufanya hivyo badala wote mara moja.

1056
01:06:48,420 --> 01:06:52,310
Kutambua HTML5 kuwa haina madhubuti zinahitaji hii slash,

1057
01:06:52,310 --> 01:06:55,410
hivyo utaona vitabu na rasilimali online kwamba hawana hiyo,

1058
01:06:55,410 --> 01:06:59,780
lakini kwa hatua nzuri hebu mazoezi ulinganifu kwamba tumekuwa kuonekana hivi sasa.

1059
01:06:59,780 --> 01:07:02,870
Hii ina maana kwamba wote tag ni kufunguliwa na imefungwa.

1060
01:07:02,870 --> 01:07:05,220
Hivyo sasa basi mimi ila faili yangu, kurudi nyuma hapa.

1061
01:07:05,220 --> 01:07:10,240
Okay, kwa hivyo ni mapya kwa kuangalia bora, isipokuwa Mtandao najua ni aina ya Clickable,

1062
01:07:10,240 --> 01:07:13,610
na bado youtube hapa haionekani kusababisha kitu chochote.

1063
01:07:13,610 --> 01:07:17,560
Hiyo ni kwa sababu hata kama inaonekana kama kiungo, browser hajui kwamba per se,

1064
01:07:17,560 --> 01:07:20,670
hivyo nina kuwaambia browser kwamba hii ni kiungo.

1065
01:07:20,670 --> 01:07:22,620
>> njia ya kufanya hili ni kwa kutumia tag nanga:

1066
01:07:22,620 --> 01:07:26,770
<Href kwa mfumuko kumbukumbu, ambayo ni umri wa shule ya njia ya kusema kiungo,

1067
01:07:26,770 --> 01:07:35,900
= "Http://www.youtube.com">

1068
01:07:35,900 --> 01:07:38,490
na napenda hoja hii kwa mstari mpya tu hivyo ni kidogo zaidi someka,

1069
01:07:38,490 --> 01:07:40,060
na mimi itabidi shrink ukubwa font.

1070
01:07:40,060 --> 01:07:43,890
Mimi ni kufanyika bado? No Itakuja kuwa hii dichotomy.

1071
01:07:43,890 --> 01:07:46,760
Hii tag, tag nanga, haina kweli kuchukua sifa,

1072
01:07:46,760 --> 01:07:52,900
ambayo hugeuza tabia yake, na thamani ya sifa ya kuwa ni inaonekana URL YouTube.

1073
01:07:52,900 --> 01:07:56,380
Lakini taarifa dichotomy ni kwamba kwa sababu tu kwamba URL utaenda,

1074
01:07:56,380 --> 01:08:01,020
hiyo haina maana kwamba ina kuwa neno kwamba wewe ni betona na maamuzi ya kiungo.

1075
01:08:01,020 --> 01:08:03,960
Badala yake, ambayo inaweza kuwa kitu kama hiki.

1076
01:08:03,960 --> 01:08:10,870
Hivyo mimi kusema kuacha kufanya neno hili kwa kutumia hyperlink karibu nanga tag.

1077
01:08:10,870 --> 01:08:12,650
Ilani Mimi si kufanya hili.

1078
01:08:12,650 --> 01:08:15,890
1, hii ingekuwa tu ni kupoteza muda wa kila mtu na si lazima.

1079
01:08:15,890 --> 01:08:19,290
>> Kuifunga tag, wewe tu kutaja jina la tag tena.

1080
01:08:19,290 --> 01:08:21,800
Huwezi kutaja yoyote ya sifa.

1081
01:08:21,800 --> 01:08:26,189
Basi hebu kuokoa, kurudi nyuma. Okay, voilà, sasa ni rangi ya bluu na hyperlinked.

1082
01:08:26,189 --> 01:08:29,430
Kama mimi bonyeza yake, mimi kwa kweli kufanya kwenda YouTube.

1083
01:08:29,430 --> 01:08:32,529
Hivyo hata kama mtandao wangu ukurasa si juu ya Internet, ni angalau HTML,

1084
01:08:32,529 --> 01:08:37,930
na kama sisi basi Internet catch up, tunataka kweli kuishia hapa kwenye youtube.com.

1085
01:08:37,930 --> 01:08:40,670
Na naweza kurudi nyuma na hapa ni mtandao wangu ukurasa. Lakini taarifa hii.

1086
01:08:40,670 --> 01:08:43,120
Kama ve milele wamezipata spam au shambulio la hadaa,

1087
01:08:43,120 --> 01:08:45,850
sasa una uwezo baada ya dakika tano tu ya kufanya hivyo.

1088
01:08:45,850 --> 01:08:50,920
Tunaweza kwenda hapa na kufanya kitu kama www.badguy.com

1089
01:08:50,920 --> 01:08:59,319
au chochote tovuti sketchy ni, na kisha unaweza kusema kuthibitisha akaunti yako PayPal.

1090
01:08:59,319 --> 01:09:04,840
[Kicheko] Na sasa hii ni ya kwenda kwenda badguy.com, ambayo mimi si kwenda na bonyeza

1091
01:09:04,840 --> 01:09:08,000
kwa sababu mimi sina wazo ambapo ambayo inaongoza. [Kicheko]

1092
01:09:08,000 --> 01:09:10,859
>> Lakini sisi sasa kuwa na uwezo wa kweli kuishia hapo.

1093
01:09:10,859 --> 01:09:12,640
Hivyo sisi ni kweli tu mapya scratch ya uso.

1094
01:09:12,640 --> 01:09:15,830
Sisi siyo programu per se, sisi ni kuandika ghafi lugha.

1095
01:09:15,830 --> 01:09:18,569
Lakini kwa haraka kama sisi pande zote nje ya msamiati wetu katika HTML,

1096
01:09:18,569 --> 01:09:21,520
tutaweza kuanzisha PHP, halisi ya programu ya lugha

1097
01:09:21,520 --> 01:09:26,859
ambayo itaruhusu sisi kuzalisha HTML moja kwa moja, kuzalisha CSS moja kwa moja,

1098
01:09:26,859 --> 01:09:29,430
ili tuweze kuanza Jumatano kutekeleza, kusema,

1099
01:09:29,430 --> 01:09:31,700
tafuta injini yetu wenyewe na zaidi.

1100
01:09:31,700 --> 01:09:34,770
Lakini zaidi juu ya kwamba katika siku kadhaa. Tutaweza kuona wewe hapo.

1101
01:09:34,870 --> 01:09:39,000
>> [CS50.TV]