1
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>> [Daqq tal-mużika]

2
00:00:02,880 --> 00:00:10,580

3
00:00:10,580 --> 00:00:13,500
>> SPEAKER 1: Dan huwa CS50 u
dan huwa l-bidu ta 'ġimgħatejn.

4
00:00:13,500 --> 00:00:18,400
Allura, ejja adsa dritt fis xi ħaġa
jiġifieri Buggy, biex ngħidu hekk.

5
00:00:18,400 --> 00:00:24,015
Allura, minn hawn huwa IDE CS50 u stajt
jinġibed minn qabel din screen-- kkritikat

6
00:00:24,015 --> 00:00:25,070
it.

7
00:00:25,070 --> 00:00:25,760
Twissija Spoiler.

8
00:00:25,760 --> 00:00:26,260
Kull dritt.

9
00:00:26,260 --> 00:00:29,060
Stajt jinġibed up dan l-iskrin hawn,
li għandha programm sempliċi ħafna.

10
00:00:29,060 --> 00:00:32,659
Jekk aħna iscroll isfel, l-aktar
ta 'dan huwa biss kummenti,

11
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iżda hawnhekk fil-linji 13 permezz
17 għandna programm.

12
00:00:36,730 --> 00:00:40,580
>> Huwa sintattikament valida, li jfisser li jekk
I josservawha, se tiġbor u run,

13
00:00:40,580 --> 00:00:41,920
imma hija Buggy.

14
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Dan il-programm tallega fil-kummenti
top up li għandu jistampa istilel 10,

15
00:00:47,330 --> 00:00:48,870
iżda ma.

16
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U bbażata fuq l-esperjenza tiegħek,
jew dalwaqt ikunu esperjenza ma C,

17
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tista loġikament jagħrfu
għaliex dan huwa, fil-fatt, Buggy?

18
00:00:56,820 --> 00:00:57,804
Yeah?

19
00:00:57,804 --> 00:00:59,220
UDJENZA: Hija tmur minn żero sa 10.

20
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C'est 11 iterazzjonijiet.

21
00:01:01,884 --> 00:01:02,550
SPEAKER 1: Yeah.

22
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Allura, li għaddej minn żero
up permezz ta 'u ugwali għal 10,

23
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li naturalment huwa 11 iterazzjonijiet.

24
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Allura, li għaddej biex
print, tabilħaqq, 11 istilel.

25
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Għalhekk, il-konvenzjoni xjenza tal-kompjuter
fil-lingwi aktar l-ipprogrammar

26
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huwa, tabilħaqq, biss biex
jibdew jingħaddu żero,

27
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iżda għadd sa, iżda mhux permezz tal-
valur li inti fil-fatt jimpurtahom.

28
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>> Issa, dan huwa ħaġa waħda li
jieħu ftit jkollna użati biex

29
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u anke Scratch, imfassla kif huwa
għal nuqqas programmaturi jew non kompjuter

30
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xjentisti u għat-tfal
aktar, huwa mfassal biex ikollu

31
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tibda tgħodd ġeneralment fuq wieħed.

32
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U li l-multa.

33
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Tista 'assolutament jibdew jingħaddu
f'wieħed jekk dan huwa aktar komda.

34
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U l-għadd sa u permezz 10, iżda
inti ser tirrealizza partikolarment din il-ġimgħa

35
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u lil hinn minnha biss hekk
ħafna affarijiet fil-programmazzjoni

36
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jassumi li hija l-ewwel 0
ċifri li magħhom inti għadd,

37
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li int ser isibuha iktar faċli
biss li jsibu rwieħhom dan il-vizzju ta 'tluq

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minn żero u l-għadd sal-valur
inti jimpurtahom dritt issa mill-

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nikseb go.

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>> Allura, dak iffissat dan.

41
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Aħna mibdula l-inqas minn jew
ugwali għal ftit inqas minn.

42
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Ejja tagħti ħarsa lejn
tieni eżempju hawn.

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>> Allura, dan il-programm pretensjonijiet wisq tagħha
Kummenti up top li għandu jistampa

44
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għaxar stilla, iżda ma.

45
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X'hemm-bug hawn?

46
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>> Allura, what-- u sorry, ejja tkun ċara.

47
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10 istilel.

48
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Wieħed għal kull linja, iżda ma.

49
00:02:11,644 --> 00:02:14,810
Allura, fil-fatt, let me imorru quddiem u jikkumpilaw
dan wieħed għaliex dan huwa ftit inqas

50
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ċara bbażata fuq dik id-deskrizzjoni.

51
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Let me jmorru fil-direttorju sors tagħna.

52
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Jagħmlu Buggy wieħed dot mmejla, wieħed Buggy.

53
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OK, nara 11 stilla, li
għadu problematiku,

54
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iżda dawn qed wkoll kollha f'linja waħda.

55
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X'hemm il-kwistjoni hawnhekk?

56
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Yeah.

57
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UDJENZA: [inaudible].

58
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59
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SPEAKER 1: Yeah.

60
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Allura dan huwa subtlety li inti tista
ifakkar me ġew imsemmija fil-qosor ta '.

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Anki jekk kollox jistenna
pretty, u huwa nicely inċiża,

62
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u huwa tip ta 'jistenna Scratch like
f'dik il-linja 16 u 17 huma,

63
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tabilħaqq, inċiża taħt dik għall loop.

64
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Li immaterjali.

65
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Il-kompjuter ma
jafu jew tara l-ispazju abjad.

66
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Ispazju abjad huwa biss għall
us bnedmin, stylistically.

67
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Il-kompjuter ma taf meta għandek
ċingi kaboċċi, li, tabilħaqq,

68
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tiffissa din il-problema.

69
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>> Allura, jekk aħna verament marru fi u
espliċitament tpoġġi f'dawn ċineg kaboċċi

70
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li tiffissa din il-problema billi
kienet tiċċara l-kumpilatur

71
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li I attwalment tixtieq li tesegwixxi
żewġ linji ta 'kodiċi darb'oħra,

72
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u għal darb'oħra, u għal darb'oħra.

73
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Imma x'inhu l-ispjegazzjoni fundamentali?

74
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Dritt?

75
00:03:12,180 --> 00:03:15,260
Aħna ma bżonn strettament
kaboċċi ċingi-ħin kollu,

76
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anki jekk huwa probabbilment l-aħjar
prattika li jsibu rwieħhom li drawwa xorta waħda

77
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anki jekk iżid żewġ
karattri għall-kodiċi tiegħek. għaliex?

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>> UDJENZA: [inaudible]?

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SPEAKER 1: Yeah b'tali mod li
Soluzzjoni oħra għal kollox.

80
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Dritt?

81
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Speċjalment jekk fl-ewwel daqqa t'għajn inti ma
verament japprezzaw x'inhu għaddej.

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Well, żgur nistgħu
biss tagħmel żewġ affarijiet f'daqqa

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u biss jevitaw il-problema għal kollox.

84
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U li l-multa, iżda issa,
għal skopijiet lum, dak

85
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hija l-ispjegazzjoni għall-bug?

86
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Għaliex kienu dawk kollha istilel fuq linja waħda?

87
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Yeah?

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>> UDJENZA: Jidher li jekk
għandek linja waħda tal-kodiċi,

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inti tista 'tagħmel dan mingħajr dawn.

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SPEAKER 1: Eżattament.

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Dan huwa biss konvenzjoni tal-bniedem.

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Nies jirrealizzaw li din hija
ftit annoying jew tedious

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li jkollhom jitqiegħdu ċineg kaboċċi kollha
tal-ħin jekk kull ma tkun trid tagħmel

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hija tesegwixxi linja waħda tal-kodiċi.

95
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Allura, il-bnedmin iddeċieda xi
żmien ilu li li l-multa.

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Jekk inti tixtieq li tqiegħed kollha ta 'loop tiegħek
fuq biss dik il-linja wieħed bħal dan,

97
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li l-multa bl-uniku
virgola fi tmiem.

98
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Iżda int tista 'biss tagħmel waħda tali
linja mingħajr il-braces kaboċċi.

99
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>> Allura, meta Gwida tal-Istil CS50
kif se punt inti għal,

100
00:04:09,900 --> 00:04:11,980
tkun taf tara li ġeneralment
huwa drawwa tajba

101
00:04:11,980 --> 00:04:14,920
li jsibu rwieħhom dan sakemm int
straying pjuttost komdu

102
00:04:14,920 --> 00:04:17,404
minn dawn it-tipi ta 'konvenzjonijiet
u tagħmel ħaġa tiegħek stess.

103
00:04:17,404 --> 00:04:18,820
Sakemm int awto konsistenti.

104
00:04:18,820 --> 00:04:21,540
U aħna ser nitkellmu aktar dwar
stil ftit aktar tard illum.

105
00:04:21,540 --> 00:04:23,200
>> Allura, let me jiftħu programm ieħor.

106
00:04:23,200 --> 00:04:24,930
Of course, għandna
jiffissaw li 10 kif ukoll.

107
00:04:24,930 --> 00:04:32,470
Let me imorru quddiem u jiktbu reali
programm ta 'malajr li I ser sejħa,

108
00:04:32,470 --> 00:04:38,140
ejja ngħidu, loop dot C. Allura, loop dot C.
U fil loop dot C jien ser ikollhom,

109
00:04:38,140 --> 00:04:41,970
jinkludu I standard / O
dot H int null prinċipali.

110
00:04:41,970 --> 00:04:44,020
U issa ejja biss tagħmel, tabilħaqq, loop.

111
00:04:44,020 --> 00:04:46,020
Allura, 4 int I gets zero.

112
00:04:46,020 --> 00:04:48,660
I huwa inqas minn, ngħidu aħna, 50.

113
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I plus, plus.

114
00:04:49,950 --> 00:04:53,350
U allura fil hawn ejja
imorru quddiem u ma jistampaw F.

115
00:04:53,350 --> 00:04:56,400
U mbagħad I tixtieq li jistampaw I
u linja ġdida, virgola.

116
00:04:56,400 --> 00:05:00,015
>> U dan għandu jistampa l-
numri mill żero sa 50?

117
00:05:00,015 --> 00:05:02,900

118
00:05:02,900 --> 00:05:03,680
A ras ftit nods.

119
00:05:03,680 --> 00:05:04,270
Ftit nos.

120
00:05:04,270 --> 00:05:05,339
X'hemm-bug diġà?

121
00:05:05,339 --> 00:05:06,630
X'hemm l-iżball faċli I magħmula?

122
00:05:06,630 --> 00:05:07,170
Yeah.

123
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>> UDJENZA: [inaudible].

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00:05:08,544 --> 00:05:09,210
SPEAKER 1: Yeah.

125
00:05:09,210 --> 00:05:11,520
Allura anke jekk jidher
bħal dan huwa dak I-intenzjoni,

126
00:05:11,520 --> 00:05:13,920
ifakkar li I wkoll
biss karattru ASCII.

127
00:05:13,920 --> 00:05:14,955
>> Għalhekk, jekk ngħid, print "I."

128
00:05:14,955 --> 00:05:16,670
Huwa litteralment għaddej
li jistampaw I. Għalhekk, jekk I

129
00:05:16,670 --> 00:05:20,030
jridu plug-in placeholder
valur I attwalment bżonn tagħmel dan

130
00:05:20,030 --> 00:05:22,630
u mbagħad-plagg fil-
valur tal I dinamiku.

131
00:05:22,630 --> 00:05:25,200
Inkella Jien biss ser
jiksbu 50s I fuq l-iskrin.

132
00:05:25,200 --> 00:05:28,140
>> Allura, let me imorru quddiem u
jagħmlu dan loop, run,

133
00:05:28,140 --> 00:05:30,650
u, tabilħaqq, aħna għandna kollha
il-mod up permezz 49.

134
00:05:30,650 --> 00:05:34,140
U jekk I iscroll lura fil-ħin nara
in-numru żero fil-bidu.

135
00:05:34,140 --> 00:05:36,050
>> Ukoll, dak li jekk I tip ta 'screw up?

136
00:05:36,050 --> 00:05:37,800
X'jiġri jekk I do dan?

137
00:05:37,800 --> 00:05:40,120
Sempliċiment għax jien ma jaħsbu.

138
00:05:40,120 --> 00:05:40,970
X'hemm dan il-programm.

139
00:05:40,970 --> 00:05:43,970
Ladarba qed miġbura u run,
se tagħmel loġikament?

140
00:05:43,970 --> 00:05:44,870
>> UDJENZA: Xejn.

141
00:05:44,870 --> 00:05:45,661
>> SPEAKER 1: Xejn.

142
00:05:45,661 --> 00:05:47,156
Għaliex huwa li?

143
00:05:47,156 --> 00:05:49,124
>> UDJENZA: I hija mfassla għall zero.

144
00:05:49,124 --> 00:05:51,899
Għalhekk, il-kundizzjoni hija falza.

145
00:05:51,899 --> 00:05:52,940
SPEAKER 1: Yeah, eżattament.

146
00:05:52,940 --> 00:05:55,110
Kollha l-kodiċi hija korretta, sintattikament.

147
00:05:55,110 --> 00:05:57,310
Dan se jiġbor, dan
kodiċi se run, iżda mhux

148
00:05:57,310 --> 00:06:00,110
se jagħmlu xi ħaġa utli
minħabba I initialize I għal żero.

149
00:06:00,110 --> 00:06:02,240
Aħna mbagħad tiċċekkja, hija I akbar minn 50?

150
00:06:02,240 --> 00:06:03,810
Ovvjament, l-ebda, mhuwiex.

151
00:06:03,810 --> 00:06:05,760
Allura l-linja qatt tesegwixxi fil-livelli kollha.

152
00:06:05,760 --> 00:06:09,580
>> X'jiġri jekk nagħmlu xi ħaġa
ftit aktar imprudenti?

153
00:06:09,580 --> 00:06:12,890
Allura, dak li jekk aħna do simili int I gets zero.

154
00:06:12,890 --> 00:06:15,640
U issa let me jużaw il-waqt
loop, li kien kundizzjoni oħra.

155
00:06:15,640 --> 00:06:21,810
U filwaqt I say, filwaqt I huwa akbar minn
jew ugwali għal żero, u mbagħad fil hawn I

156
00:06:21,810 --> 00:06:26,070
imorru quddiem u jiffrankaw l-fajl, jagħmlu loop.

157
00:06:26,070 --> 00:06:27,070
U jien ser run.

158
00:06:27,070 --> 00:06:30,230
What am I se tara dan
darba bil-linja waqt?

159
00:06:30,230 --> 00:06:30,852
Yeah.

160
00:06:30,852 --> 00:06:32,120
>> UDJENZA: An loop infinita?

161
00:06:32,120 --> 00:06:35,360
>> SPEAKER 1: An loop infinita?

162
00:06:35,360 --> 00:06:36,662
Iva, u għaliex?

163
00:06:36,662 --> 00:06:38,120
UDJENZA: Għaliex dan huwa dejjem żero.

164
00:06:38,120 --> 00:06:38,786
SPEAKER 1: Yeah.

165
00:06:38,786 --> 00:06:40,100
So, I huwa initialized bħala zero.

166
00:06:40,100 --> 00:06:44,470
Of course I tkun dejjem ikbar
minn jew ugwali għal 0 bħala riżultat.

167
00:06:44,470 --> 00:06:46,460
Allura, jien biss ser
tara dan infinitament.

168
00:06:46,460 --> 00:06:49,850
U issa, din għandha toħroġ darba
jew darbtejn biex irjus tal-kors ta.

169
00:06:49,850 --> 00:06:52,417
X'jiġri meta inti
jkollhom loop infinita?

170
00:06:52,417 --> 00:06:53,314
>> UDJENZA: Kontroll C.

171
00:06:53,314 --> 00:06:53,980
SPEAKER 1: Yeah.

172
00:06:53,980 --> 00:06:56,250
Allura Kontroll C eventwalment se jirrispondi.

173
00:06:56,250 --> 00:06:59,520
Sfortunatament, konna stampata
miljuni u miljuni ta 'zeroes diġà

174
00:06:59,520 --> 00:07:01,520
u għalhekk il-kompjuter għandu
tip ta 'ltqajna qabel iż me.

175
00:07:01,520 --> 00:07:03,394
Allura, li għaddej biex jinjoraw
me għal ftit.

176
00:07:03,394 --> 00:07:06,560
Imma jekk inti biss hit Kontroll C ftit
ħinijiet fuq tiegħek Mac jew PC tastiera,

177
00:07:06,560 --> 00:07:08,790
eventwalment għandu, tabilħaqq, ittemm.

178
00:07:08,790 --> 00:07:11,770
U jekk le, aħna ser nuruk xi
tekniki qabel twil fejn inti

179
00:07:11,770 --> 00:07:14,850
jista 'effettivament joqtol bil-forza programmi,
ferm simili fil-Windows u Mac OS,

180
00:07:14,850 --> 00:07:15,562
jekk ikun hemm bżonn.

181
00:07:15,562 --> 00:07:16,770
Imma ejja ipprova xi ħaġa oħra.

182
00:07:16,770 --> 00:07:19,895
Ejja attwalment inkrement I.
dan xorta se tkun infinita?

183
00:07:19,895 --> 00:07:22,870

184
00:07:22,870 --> 00:07:25,140
Let me run dan.

185
00:07:25,140 --> 00:07:27,090
U issa inti tista tip ta '
tara x'inhu jiġri.

186
00:07:27,090 --> 00:07:30,140
Dan, ukoll, huwa loop infinita.

187
00:07:30,140 --> 00:07:33,080
Iżda din hija daqsxejn ta 'mistoqsija trick.

188
00:07:33,080 --> 00:07:35,460
Huwa dan morna għall-istampa numri dejjem?

189
00:07:35,460 --> 00:07:36,647
>> UDJENZA: Le

190
00:07:36,647 --> 00:07:37,230
SPEAKER 1: Le

191
00:07:37,230 --> 00:07:37,620
Għaliex?

192
00:07:37,620 --> 00:07:38,820
Smajt xi nos hawn fuq.

193
00:07:38,820 --> 00:07:41,859
Someone-- Yeah.

194
00:07:41,859 --> 00:07:44,275
UDJENZA: Inti ma għandekx biżżejjed
bits biex verament jibqgħu għaddejjin.

195
00:07:44,275 --> 00:07:44,730
SPEAKER 1: Id-dritt.

196
00:07:44,730 --> 00:07:46,000
So I ma jkollhomx biżżejjed
bits biex jibqgħu għaddejjin.

197
00:07:46,000 --> 00:07:47,124
Allura, dak li jiġri?

198
00:07:47,124 --> 00:07:49,320
Huwa biss ser tieqaf?

199
00:07:49,320 --> 00:07:52,542
>> UDJENZA: F'xi punt
se shut the--

200
00:07:52,542 --> 00:07:54,500
SPEAKER 1: Se shut
l isfel loop, iżda għaliex?

201
00:07:54,500 --> 00:07:57,950
X'hemm jiġri fil-
ħafna aħħar tal-konfini tagħha?

202
00:07:57,950 --> 00:07:58,479
Yeah?

203
00:07:58,479 --> 00:08:00,520
UDJENZA: Se ċiklu
lura għal numri negattivi.

204
00:08:00,520 --> 00:08:02,900
SPEAKER 1: Biex numri negattivi, jew
jekk konna biss trattament pożittiv,

205
00:08:02,900 --> 00:08:03,570
żero mill-inqas.

206
00:08:03,570 --> 00:08:04,550
Allura iva, assolutament.

207
00:08:04,550 --> 00:08:08,059
Ifakkar li rajna aħħar darba li jekk inti
inkrement bits tiegħek wieħed wisq drabi,

208
00:08:08,059 --> 00:08:10,225
u inti hemm għalhekk overflow
il-kapaċità ta 'int tiegħek

209
00:08:10,225 --> 00:08:13,058
jew kwalunkwe tip tad-data hija, int
se perimetrika, probabbilment,

210
00:08:13,058 --> 00:08:14,020
żewġ numri negattivi.

211
00:08:14,020 --> 00:08:16,644
Jew jekk inti stajt tispeċifika li tiegħek
firxa għandu jkun pożittiv biss,

212
00:08:16,644 --> 00:08:18,560
li inti tista 'tagħmel, imma
konna ma jidher li għadhom,

213
00:08:18,560 --> 00:08:21,420
inti tista 'tispiċċa mill-inqas lura fuq iż-żero.

214
00:08:21,420 --> 00:08:22,410
Għalkemm, fil-fatt iva.

215
00:08:22,410 --> 00:08:24,320
F'dan il-każ, negattiv
numri, f'liema każ

216
00:08:24,320 --> 00:08:26,870
il-linja se jtemm
minħabba I ma tkunx, fil-fatt,

217
00:08:26,870 --> 00:08:29,220
ikbar minn jew ugwali għal
żero jekk huwa negattiv.

218
00:08:29,220 --> 00:08:31,780
>> Allura, sfortunatament, kif
żmien ser irridu nistennew?

219
00:08:31,780 --> 00:08:35,490
Dritt issa aħna qed sa
dak, 2 miljuni ish?

220
00:08:35,490 --> 00:08:37,705
Aħna bħal 2 biljun,
aħna qed tmur biex ikollhom jistennew

221
00:08:37,705 --> 00:08:39,330
sakemm nistgħu ngħidu tara dan sintomu.

222
00:08:39,330 --> 00:08:46,200
Iżda nistgħu naraw hija ftit aktar mgħaġġla,
maybe-- ejja ara jekk nistgħu jinterrompi.

223
00:08:46,200 --> 00:08:46,700
Come fuq.

224
00:08:46,700 --> 00:08:49,500

225
00:08:49,500 --> 00:08:51,331
Anki l-menus qed jidhru bil-mod.

226
00:08:51,331 --> 00:08:51,830
Kull dritt.

227
00:08:51,830 --> 00:08:54,270
Allura, aħna ser terga 'lura għal li qabel twil.

228
00:08:54,270 --> 00:08:56,320
Huwa tajjeb time-- kkritikat dan, ġriewi.

229
00:08:56,320 --> 00:08:58,280
>> Huwa żmien tajjeb għal xi avviżi.

230
00:08:58,280 --> 00:09:01,225
Allura, jekk inti tista 'tixtieq
li jidħlu fl YHack,

231
00:09:01,225 --> 00:09:03,600
li hija avveniment qed
sponsorjati mill-ħbieb tagħna fil Yale.

232
00:09:03,600 --> 00:09:05,990
U, tabilħaqq, xi wħud mill-l-kors
TFS fil-Yale huma involuti ma 'dan.

233
00:09:05,990 --> 00:09:08,610
YHack huwa internazzjonali
Hack-a-Thon ospitat mill u miżmuma

234
00:09:08,610 --> 00:09:12,395
fil-Yale, li jġibu flimkien 1500
bħal hackers b'moħħhom u creatives kollha

235
00:09:12,395 --> 00:09:13,120
madwar id-dinja.

236
00:09:13,120 --> 00:09:14,610
Jekk dan huwa ta 'interess,
tagħti ħarsa hawn.

237
00:09:14,610 --> 00:09:17,401
Jekk dan huwa wisq fil-qosor fuq il-
screen, tagħti ħarsa lejn slides lum

238
00:09:17,401 --> 00:09:19,622
għall-URL għall yhack.org.

239
00:09:19,622 --> 00:09:21,080
Allura, ukoll ftit avviżi malajr.

240
00:09:21,080 --> 00:09:24,410
Allura, uffiċjalment sezzjonijiet ser tibda
ġimgħa d-dieħla kemm hawn u New Haven.

241
00:09:24,410 --> 00:09:27,660
Wieħed iżomm f'moħħu li inti ser tkun jkollna
email aktar tard dan il-weekend l-aktar probabbli.

242
00:09:27,660 --> 00:09:29,390
Huwa jieħu żmien twil
għall CS50 sezzjoni,

243
00:09:29,390 --> 00:09:32,080
mogħtija l-poplu kollu fil-
klassi u kulħadd li jiċċaqalqu madwar.

244
00:09:32,080 --> 00:09:34,871
U l-Fellows Tagħlim "
iskedi huma wkoll għadhom solidifying,

245
00:09:34,871 --> 00:09:38,110
iżda tissospendi sintonizzat għal email u jekk ikun hemm bżonn
jiġu, inti tista 'sezzjoni mill-ġdid hemmhekk wara.

246
00:09:38,110 --> 00:09:39,580
>> Study.cs50.net.

247
00:09:39,580 --> 00:09:43,280
Għalhekk, anki jekk inti attendee kostanti
fis-sezzjonijiet, tirrealizza li kważi kollha

248
00:09:43,280 --> 00:09:46,786
tar-riżorsi li nużaw fit-taqsimiet
huma disponibbli pubblikament fuq CS50

249
00:09:46,786 --> 00:09:48,460
Studju f'dan URL hawn.

250
00:09:48,460 --> 00:09:51,630
Allura, jekk youd qatt tixtieq li terġa 'reviżjoni
materjal mit-taqsima, jew aqra l quddiem,

251
00:09:51,630 --> 00:09:54,170
jew inti ma tistax tagħmel dan xi ġimgħa,
jirrealizzaw li slides kampjun,

252
00:09:54,170 --> 00:09:58,210
u l-problemi, u d-definizzjonijiet,
u aktar huma kollha hemm ukoll.

253
00:09:58,210 --> 00:10:00,645
>> Ħinijiet tal-uffiċċju jerġa llum,
u għada, u l-Erbgħa,

254
00:10:00,645 --> 00:10:03,020
u l-Ħamis jivverifika l-kors ta
websajt għall-iskeda.

255
00:10:03,020 --> 00:10:05,690
>> U wkoll, issa tniedi
illum huwa CS50 Iddiskuti.

256
00:10:05,690 --> 00:10:09,230
Allura, jekk u meta ikollok aktar mistoqsijiet għal
xulxin jew għall-ħaddiema tal-kors, l

257
00:10:09,230 --> 00:10:12,099
u ġeneralment qegħdin jaħdmu
fuq xi sett problema,

258
00:10:12,099 --> 00:10:15,015
tirrealizza li inti ma neċessarjament
li jduru għall-bniedem li jmiss inti.

259
00:10:15,015 --> 00:10:17,810
Jekk hemm l-ebda waħda hemm, inti tista '
jilħqu lilna u klassi

260
00:10:17,810 --> 00:10:19,890
onlajn permezz CS50 Iddiskuti.

261
00:10:19,890 --> 00:10:22,600
Allura, dan huwa diskussjoni
board għall-kors,

262
00:10:22,600 --> 00:10:24,550
u jirrealizzaw li dan
hija forsi l-aħjar

263
00:10:24,550 --> 00:10:28,480
post biex tibda meta jkollok
mistoqsijiet meta barra ta 'ħinijiet tal-uffiċċju

264
00:10:28,480 --> 00:10:29,470
partikolarment.

265
00:10:29,470 --> 00:10:31,070
>> Ikliet se jibdew din il-ġimgħa wisq.

266
00:10:31,070 --> 00:10:33,170
Fil nar u Silġ
[Inaudible] fi New Haven.

267
00:10:33,170 --> 00:10:35,379
Agħti ħarsa lejn l-kors ta
websajt biex RSVP.

268
00:10:35,379 --> 00:10:36,753
First come, first jservu għal dan.

269
00:10:36,753 --> 00:10:39,380
Jekk inti ma tieħux fl din il-ġimgħa
aħna ser nagħmlu dawn l-aktar kull Ġimgħa

270
00:10:39,380 --> 00:10:40,400
matul it-terminu.

271
00:10:40,400 --> 00:10:41,830
>> OK, u issa kelma dwar gradazzjoni.

272
00:10:41,830 --> 00:10:44,690
Partikolarment kif aħna jidħlu problema
sett wieħed, li huwa barra din il-ġimgħa,

273
00:10:44,690 --> 00:10:46,670
u l-problema sett tnejn u wara.

274
00:10:46,670 --> 00:10:51,680
Kif do we go dwar evalwazzjoni settijiet P
u evalwazzjoni tal-kwalità tiegħu?

275
00:10:51,680 --> 00:10:55,560
Għalhekk, huwa erba 'assi li nużaw fil
CS50, u dawn qed dawn l-erba hawn.

276
00:10:55,560 --> 00:10:59,200
>> Kamp ta 'applikazzjoni, li jaqbad fuq numerika
bażi biss kemm tal-P sett

277
00:10:59,200 --> 00:10:59,860
ma inti jindirizzaw.

278
00:10:59,860 --> 00:11:02,890
Huwa bejn wieħed u ieħor jikkorrispondi mal
isforz, u huwa mod tagħna ta 'qbid

279
00:11:02,890 --> 00:11:05,190
ma inti tipprova nofs il-P
sett, kollha tal-P sett.

280
00:11:05,190 --> 00:11:08,860
Din hija waħda faċli li tinkiseb perfetta
punteġġi fuq jekk inti tagħmel, tabilħaqq,

281
00:11:08,860 --> 00:11:11,020
tipprova kull aspett tal-P sett.

282
00:11:11,020 --> 00:11:12,010
Allura, iżommu dan f'moħħhom.

283
00:11:12,010 --> 00:11:13,420
>> Korrettezza huwa eżattament dak.

284
00:11:13,420 --> 00:11:17,760
Jaħdem kodiċi tiegħek bħala l-ispeċifikazzjoni
u bħala soluzzjoni tal-kampjun l-istaff "

285
00:11:17,760 --> 00:11:19,730
jissuġġerixxu li kodiċi tiegħek
għandhom, fil-fatt, ix-xogħol.

286
00:11:19,730 --> 00:11:23,260
Iċċekkja 50, jekk inti ma laħqux dan
għadhom, huwa P stabbilit ispeċifikazzjoni wieħed

287
00:11:23,260 --> 00:11:25,060
u se ġeneralment
jtik iva / le tweġibiet

288
00:11:25,060 --> 00:11:26,518
dwar jekk kodiċi tiegħek hija korretta.

289
00:11:26,518 --> 00:11:30,680
Mill-inqas sa fejn aħna qed tmur
tevalwaha abbażi tat-testijiet

290
00:11:30,680 --> 00:11:32,430
li aħna run fi ħdan dak il-programm.

291
00:11:32,430 --> 00:11:33,850
>> Disinn huwa ħafna aktar suġġettivi.

292
00:11:33,850 --> 00:11:35,994
Dan huwa kif ukoll bil-miktub huwa kodiċi tiegħek.

293
00:11:35,994 --> 00:11:38,410
U din hija xi ħaġa li
int ser tingħata aħjar fil maż-żmien,

294
00:11:38,410 --> 00:11:41,201
u huwa xi ħaġa li aħna ser
jipprovdu aktar rispons kwalitattiv fuq.

295
00:11:41,201 --> 00:11:43,350
U permezz tad-disinn I jista
jfissirx qabel twil inti

296
00:11:43,350 --> 00:11:47,650
jista 'jitħajjar f'xi P
stabbiliti biex jagħmlu xi ħaġa loopingly,

297
00:11:47,650 --> 00:11:51,590
iżda li jkollhom forsi tlieta, jew erba ', jew
ħames linji ta 'quddiem nested jew waqt nested

298
00:11:51,590 --> 00:11:52,090
loops.

299
00:11:52,090 --> 00:11:54,130
Li ġeneralment għandhom
tibda tagħmel inti cringe

300
00:11:54,130 --> 00:11:56,070
u ġeneralment ikun
meqjus disinn ħażin.

301
00:11:56,070 --> 00:11:59,490
U tkun taf tibda tara fil-klassi u
minn modi klassi tajbin ta 'nagħmlu l-affarijiet,

302
00:11:59,490 --> 00:12:02,920
modi ħżiena ta 'nagħmlu l-affarijiet li
kollha jistgħu jkunu korretti, iżda mhux

303
00:12:02,920 --> 00:12:04,304
neċessarjament mfassla tajjeb.

304
00:12:04,304 --> 00:12:05,220
Bħall-kitba ta 'esej.

305
00:12:05,220 --> 00:12:08,100
Inti jista 'jkun kapaċi li jitpoġġew kelma dwar
paġna li huma grammatikament korretti,

306
00:12:08,100 --> 00:12:10,016
iżda l-essay jew l
teżi li qed fl huwa biss

307
00:12:10,016 --> 00:12:11,810
kompletament inkoerenti jew unpersuasive.

308
00:12:11,810 --> 00:12:15,930
U hekk li jista 'jkun l-Analog fis-
dinja miktub ta 'disinn ħażin jew tajjeb.

309
00:12:15,930 --> 00:12:18,490
>> U stil, ukoll, hija pjuttost suġġettiva.

310
00:12:18,490 --> 00:12:20,060
Imma l-anqas nistennew konsistenza.

311
00:12:20,060 --> 00:12:21,480
Dan huwa kif pretty huwa kodiċi tiegħek.

312
00:12:21,480 --> 00:12:22,840
Huma affarijiet nicely inċiża?

313
00:12:22,840 --> 00:12:26,600
Huma varjabbli tiegħek ukoll bl-isem / huma kollha
tal-parentesi tiegħek u braces kaboċċi

314
00:12:26,600 --> 00:12:27,920
allinjat kif għandhom jitwettqu?

315
00:12:27,920 --> 00:12:31,490
We do jkollhom Gwida tal-Istil CS50 bħala
is-sett problema se punt inti lejn.

316
00:12:31,490 --> 00:12:33,730
Dawk aktar komda huma
merħba lill iżolati minn dak

317
00:12:33,730 --> 00:12:35,771
sakemm inti self konsistenti.

318
00:12:35,771 --> 00:12:38,020
U dan, ukoll, hija lezzjoni
aħna ser issaħħaħ fis-sezzjoni.

319
00:12:38,020 --> 00:12:40,990
Allura, jekk dan kollu kien ftit
fast, tirrealizza is-sett P u sezzjonijiet

320
00:12:40,990 --> 00:12:42,900
se tidħol fis f'aktar dettal qabel ma twil.

321
00:12:42,900 --> 00:12:45,490
>> Iżda ġeneralment għandna
ftit bramel għall CS50.

322
00:12:45,490 --> 00:12:48,170
Punteġġi huma ġeneralment fuq skala
minn wieħed sa tlieta, jew 1-5.

323
00:12:48,170 --> 00:12:50,836
Aħna literally-- u ma nistax ngħid
dan biżżejjed fl-ewwel ġimgħa.

324
00:12:50,836 --> 00:12:51,582
Tliet hija tajba.

325
00:12:51,582 --> 00:12:54,290
Allura, anki jekk, iva, tlieta minn
ta 'ħames normalment, matematikament,

326
00:12:54,290 --> 00:12:57,240
jista 'jkun ta' 60 fil-mija jew bħal minus D.

327
00:12:57,240 --> 00:12:58,840
Tliet huwa, fil-fatt, tajba.

328
00:12:58,840 --> 00:13:01,050
U, fil-fatt, nistennew
aktar studenti fil-klassi

329
00:13:01,050 --> 00:13:04,280
biex tibda off-terminu madwar
twos, u threes, u fours.

330
00:13:04,280 --> 00:13:05,510
Probabbilment ma tant livell ta 'għajxien.

331
00:13:05,510 --> 00:13:06,661
Mhux wisq dawk.

332
00:13:06,661 --> 00:13:08,910
Iżda ġeneralment tibda fl
post li ħelu fil-kurva

333
00:13:08,910 --> 00:13:11,694
sabiex bħala ħin timxi,
hemm attwalment lok għal,

334
00:13:11,694 --> 00:13:13,360
u l-opportunitajiet għall-progressjoni ta 'fuq.

335
00:13:13,360 --> 00:13:15,810
Allura, jekk jogħġbok ma jistax jitqabbel tliet b'60%.

336
00:13:15,810 --> 00:13:17,410
Huwa ferm aktar astratti minn dak.

337
00:13:17,410 --> 00:13:20,160
Il-formula li biha aħna jikkalkulaw
gradi hija peżati kif ġej.

338
00:13:20,160 --> 00:13:21,610
Korrettezza min l-aktar.

339
00:13:21,610 --> 00:13:23,010
Disinn huwa jiswew ftit inqas.

340
00:13:23,010 --> 00:13:24,490
Style hija jiswew ftit inqas.

341
00:13:24,490 --> 00:13:26,950
U dan ġeneralment
jaqbad l-ammont ta 'ħin

342
00:13:26,950 --> 00:13:29,800
li tmur fil jkollna kull
ta 'dawn l-assi biss id-dritt.

343
00:13:29,800 --> 00:13:31,810
Style hija super faċli,
għandhom ikunu super malajr,

344
00:13:31,810 --> 00:13:33,657
imma hija drawwa faċli
tikseb għażżien madwar.

345
00:13:33,657 --> 00:13:35,490
Korrettezza jista 'jieħu
inti maġġoranza tal-ħin.

346
00:13:35,490 --> 00:13:38,990
Tmur fl xi wħud jistgħu bug
jieħdu dik is-siegħa żejda jew aktar,

347
00:13:38,990 --> 00:13:41,737
u għalhekk, il-punteġġ
finalment jaqbad dik.

348
00:13:41,737 --> 00:13:43,070
U hekk, issa kelma aktar serja.

349
00:13:43,070 --> 00:13:45,240
Peress CS50 għandha l-
distinzjoni, għal aħjar

350
00:13:45,240 --> 00:13:47,440
jew għall-agħar, li jkunu
forsi aħjar familjari

351
00:13:47,440 --> 00:13:50,065
mal-kwistjonijiet ta akkademika
onestà minn ħafna xi kors ieħor.

352
00:13:50,065 --> 00:13:53,720
U fil-fatt, huwa għall-għarfien tiegħi li
nibagħtu aktar studenti, sfortunatament,

353
00:13:53,720 --> 00:13:56,690
għal skopijiet dixxiplinarji
kull sena bħala riżultat. Allura,

354
00:13:56,690 --> 00:13:59,040
fl-interess tal full
iżvelar, ejja nitkellmu qosor

355
00:13:59,040 --> 00:14:02,820
dwar dak li jiġri fil CS50, u dak li inti
tista 'tagħmel, u dak li inti tista' tkun konxja ta '.

356
00:14:02,820 --> 00:14:05,530
>> Allura, hawn mill-2007, meta
I wiret il-kors,

357
00:14:05,530 --> 00:14:07,870
huwa n-numru ta 'każijiet Ad Bord.

358
00:14:07,870 --> 00:14:10,690
Ad Bord huwa dixxiplinarja Harvard
korp, jew issa l-Avukat Unur,

359
00:14:10,690 --> 00:14:13,790
li każijiet huma msemmija meta
istudenti tagħmel xi ħaġa li l-kors ta

360
00:14:13,790 --> 00:14:15,470
sillabu iqis irraġonevoli.

361
00:14:15,470 --> 00:14:17,220
M'hemm l-ebda mudell veru
hawn, nixtieq ngħid.

362
00:14:17,220 --> 00:14:19,530
Hija tvarja fuq l-
snin, iżda ġeneralment

363
00:14:19,530 --> 00:14:22,262
dan huwa n-numru ta '
każijiet li jissemmew.

364
00:14:22,262 --> 00:14:23,970
In-numru ta 'studenti
li huma involuti?

365
00:14:23,970 --> 00:14:25,290
Wisq tvarja.

366
00:14:25,290 --> 00:14:27,930
Tipikament, l-aħħar sena għal
eżempju, 29 studenti fil-Harvard

367
00:14:27,930 --> 00:14:29,740
kienu Ad telgħu abbord, biex ngħidu hekk.

368
00:14:29,740 --> 00:14:32,670
29 ta 'minnhom istudenti attwali,
Tnejn minnhom istudenti minn qabel,

369
00:14:32,670 --> 00:14:35,610
li kienu jikkollaboraw
b'xi mod mhux mixtieqa.

370
00:14:35,610 --> 00:14:38,400
U allura f'termini tal-
persentaġġ, huwa normalment ta 'madwar 3%

371
00:14:38,400 --> 00:14:41,360
tal-klassi li, sfortunatament,
jagħmel dawn it-tipi ta 'deċiżjonijiet.

372
00:14:41,360 --> 00:14:44,470
>> Allura, is-sena kien 3.5%
tal-ġisem istudenti CS50 s

373
00:14:44,470 --> 00:14:46,820
li kien Ad telgħu abbord, biex ngħidu hekk.

374
00:14:46,820 --> 00:14:48,490
>> Allura, dak ma dan kollu jfisser?

375
00:14:48,490 --> 00:14:49,660
U dak li aħna fil-fatt jagħmlu?

376
00:14:49,660 --> 00:14:52,930
>> Għalhekk, għal żvelar sħiħ, aħna
assolutament, kif xjenzjati tal-kompjuter,

377
00:14:52,930 --> 00:14:57,620
jkollhom għodod ta 'softwer għad-dispożizzjoni tagħna
u huwa faċli ħafna għalina, fil-ġustizzja,

378
00:14:57,620 --> 00:15:00,980
klassi li oħrajn li mhumiex
qsim dawn il-linji jaqsmu tqabbel

379
00:15:00,980 --> 00:15:04,570
kull sottomissjoni din is-sena kontra kull
sottomissjoni għall-aħħar tmien snin.

380
00:15:04,570 --> 00:15:05,445
Software ma dan.

381
00:15:05,445 --> 00:15:07,440
U fl-aħħarnett huwa
għajnejn tal-bniedem li jiddeċiedu

382
00:15:07,440 --> 00:15:11,410
jekk jew le li tirreferi xi
kwistjoni għal iktar aġġudikazzjoni,

383
00:15:11,410 --> 00:15:12,737
imma s-software ċertament jgħin.

384
00:15:12,737 --> 00:15:15,820
U dan, franchement, huwa għalhekk li naħseb
għandna dawn in-numri kbar fl CS50.

385
00:15:15,820 --> 00:15:18,540
Huwa mhux minħabba CS50
studenti jew studenti CS aktar

386
00:15:18,540 --> 00:15:20,840
ġeneralment huma xi inqas onesti
minn xi studenti oħra,

387
00:15:20,840 --> 00:15:22,340
huwa biss għandna l-
għodod u t-tekniki

388
00:15:22,340 --> 00:15:24,095
li biex tieħu din l-ewwel pass.

389
00:15:24,095 --> 00:15:25,960
>> Iżda aħna ma żżomm għajnejk
fuq kollha ta 'dawn l-affarijiet

390
00:15:25,960 --> 00:15:30,340
kif ukoll, għal darb'oħra, fl-interess taċ
jirrikonoxxu l-ħidma li l-jiġu mqiegħda

391
00:15:30,340 --> 00:15:32,397
fi b'maġġoranza super tal-klassi.

392
00:15:32,397 --> 00:15:34,230
U l-politika tal-kors ta
fuq l-onestà akkademika,

393
00:15:34,230 --> 00:15:37,021
anki jekk huwa mazz ta 'paragrafi
twil bil-mazz ta 'balal

394
00:15:37,021 --> 00:15:40,490
li huma wieħed jittama pjuttost tinqara, huwa
verament ma jsarrafx biss fl raġonevoli.

395
00:15:40,490 --> 00:15:44,000
U l-aħjar regola ġenerali li
noffru fi ħdan il-sillabu

396
00:15:44,000 --> 00:15:46,020
huwa dan, l-essenza
ta 'xogħol kollu li inti

397
00:15:46,020 --> 00:15:47,850
tissottometti lill dan il-kors għandu jkun tiegħek stess.

398
00:15:47,850 --> 00:15:51,510
U fil-fatt, fi kważi kollha ta 'dawk
każijiet imsemmija għal azzjoni dixxiplinarja

399
00:15:51,510 --> 00:15:55,640
kien minħabba xi student wieħed tard
lejl tipikament daru kodiċi tiegħu jew tagħha

400
00:15:55,640 --> 00:15:58,130
fuq outright għal classmate,
li mbagħad adottawha

401
00:15:58,130 --> 00:16:00,840
fl-intier tiegħu jew
b'mod sinifikanti tiegħu.

402
00:16:00,840 --> 00:16:02,680
>> Imma verament, din hija OK.

403
00:16:02,680 --> 00:16:04,684
U fil-fatt, fl-uffiċċju
sigħat, il slips tal-karta

404
00:16:04,684 --> 00:16:07,850
inti kont qed mgħoddija jekk inti waslet minn uffiċċju
sigħat aħħar ġimgħa jinkoraġġixxi kemm.

405
00:16:07,850 --> 00:16:09,710
Inti assolutament
laqa u mħeġġa

406
00:16:09,710 --> 00:16:12,340
biex jiddiskutu settijiet problema mal-klassi.

407
00:16:12,340 --> 00:16:14,461
Biex jgħinu lil xulxin meta xkiel.

408
00:16:14,461 --> 00:16:17,710
Iżda ġeneralment ir-regola ġenerali għandha
jkun dan, "meta inti qed jitolbu għall-għajnuna,

409
00:16:17,710 --> 00:16:20,412
inti tista 'turi kodiċi tiegħek lill-oħrajn,
imma inti ma tista 'tara tagħhom. "

410
00:16:20,412 --> 00:16:22,620
Allura, fi kliem ieħor, jekk jien
tissara ma 'xi sett P

411
00:16:22,620 --> 00:16:25,290
u jien hemm seduta fil-
dining sala, jew fil-librerija,

412
00:16:25,290 --> 00:16:28,470
jew fil-klassi
jippruvaw isibu xi tort,

413
00:16:28,470 --> 00:16:30,340
I jista 'ċertament juru
kodiċi tiegħi fuq l-iskrin tiegħi

414
00:16:30,340 --> 00:16:32,590
lill-persuna seduta li jmiss
lili, ċertament il-persunal,

415
00:16:32,590 --> 00:16:33,600
iżda wkoll classmate.

416
00:16:33,600 --> 00:16:36,580
Iżda jekk is-soluzzjoni li
classmate tiegħi joffri huwa, oh,

417
00:16:36,580 --> 00:16:39,200
hawn ħu ħarsa lejn dak
I did, li jaqsam il-linja.

418
00:16:39,200 --> 00:16:43,120
>> U jien DARE ngħid li ġeneralment
ħaġa raġonevoli għal ħafna nies

419
00:16:43,120 --> 00:16:45,030
li faċilment post l-linja ta '.

420
00:16:45,030 --> 00:16:47,195
U għalhekk, ara l-sillabu
għal aktar dettalji.

421
00:16:47,195 --> 00:16:49,070
U issa wieħed mill-aktar
aspetti kontroversjali

422
00:16:49,070 --> 00:16:52,529
ta sillabu CS50 li ħsibt I
se jitkellem fl konklużjoni hawn

423
00:16:52,529 --> 00:16:53,820
huwa l-hekk imsejħa klawsola dispjaċir.

424
00:16:53,820 --> 00:16:55,340
Allura, hawn l-istampar multa.

425
00:16:55,340 --> 00:16:58,090
Iżda b'mod ġenerali rajna
matul l-aħħar 8 snin flimkien

426
00:16:58,090 --> 00:17:01,510
li, tabilħaqq, kważi kollha tal CS50 s
każijiet ta 'diżonestà akkademika

427
00:17:01,510 --> 00:17:04,390
kienu r-riżultat ta 'ftit fqira
teħid tard bil-lejl deċiżjoni.

428
00:17:04,390 --> 00:17:07,144
Ir-riżultat ta 'stress, ir-riżultat
nuqqas ta 'ikel, nuqqas ta' rqad,

429
00:17:07,144 --> 00:17:09,560
wisq settijiet P, wisq
iskadenzi, wisq impenji.

430
00:17:09,560 --> 00:17:13,520
Stress bini up fil-02:00, 03:00
AM, 04:00, bi skadenza imminenti.

431
00:17:13,520 --> 00:17:17,020
Ħafna studenti f'dawn il-każijiet
għadhom kemm għamlu deċiżjonijiet ħżiena

432
00:17:17,020 --> 00:17:20,619
li dawn jistgħu tajjeb ħafna dispjaċir il
għada filgħodu jekk mhux minuti wara,

433
00:17:20,619 --> 00:17:25,490
imma sakemm aħħar sena ma kien hemm l-ebda
valv rilaxx li dawn l-istudenti jista '

434
00:17:25,490 --> 00:17:29,140
attwalment jiftħu li attwalment tindirizza l-
ras problema mingħajr biża 'li

435
00:17:29,140 --> 00:17:30,850
Booted mill-kulleġġ għal kollox.

436
00:17:30,850 --> 00:17:33,260
>> U, tabilħaqq, daħħalna
din il-klawsola dispjaċir aħħar sena,

437
00:17:33,260 --> 00:17:35,970
li jgħid li jekk fi żmien
72 siegħa, tlett ijiem,

438
00:17:35,970 --> 00:17:37,970
ta 'qsim xi linja
preskritt fis-sillabu

439
00:17:37,970 --> 00:17:41,178
inti tressaq għal waħda mill-kors tal
irjus u aħna ser ikollhom chat dwar dan.

440
00:17:41,178 --> 00:17:43,720
Għadhom 'jkun hemm xi
riżultat, kuntrarjament għal dak li

441
00:17:43,720 --> 00:17:44,990
ġie rrappurtat għall-kuntrarju.

442
00:17:44,990 --> 00:17:49,190
Għad hemm xi riżultat li
huwa azzjonabbli mill-kors,

443
00:17:49,190 --> 00:17:51,611
ġeneralment zeroing sett P
jew tieħu xi azzjoni oħra,

444
00:17:51,611 --> 00:17:53,610
imma aħna se, fil-fatt,
opera nfusna u ma

445
00:17:53,610 --> 00:17:58,460
tirreferiha ogħla kienu r-riżultat
jista 'jkun ferm aktar gravi.

446
00:17:58,460 --> 00:18:01,810
U, tabilħaqq, jaqsmu dak li ġara
sena li għaddiet, fit-tmien snin, u issa

447
00:18:01,810 --> 00:18:04,950
disa 'snin, ta' tagħlim dan il-kors
u wara tbagħbis ma 'diversi pumi,

448
00:18:04,950 --> 00:18:07,866
tidwir varji dials matul l-aħħar
diversi snin fis onestà akkademika,

449
00:18:07,866 --> 00:18:11,920
u tara per-data mhux apparenti
impatt, anki ta 'diskorsi bħal dan,

450
00:18:11,920 --> 00:18:15,490
dan kien f'idejn l-aqwa ħaġa
konna introdotti pedagoġikament

451
00:18:15,490 --> 00:18:18,090
fi tmien snin flimkien
dawn il-linji CS50.

452
00:18:18,090 --> 00:18:21,010
>> 19 studenti resqu
taħt din il-klawżola sena li għaddiet.

453
00:18:21,010 --> 00:18:23,389
Aħna baqgħu inattivi għal
sebgħa dawk l-istudenti,

454
00:18:23,389 --> 00:18:25,430
determinazzjoni li kienu
inkwetat bla bżonn.

455
00:18:25,430 --> 00:18:27,304
Huma ma kinux, fil-fatt,
qasmu linja, iżda

456
00:18:27,304 --> 00:18:28,960
kienet chat tajba li jkollhom xorta waħda.

457
00:18:28,960 --> 00:18:31,190
Aħna zeroed 11 tal-punteġġi
li kienu sottomessi.

458
00:18:31,190 --> 00:18:33,840
U f'każ wieħed staqsejna a
student li tagħmel problema stabbiliti.

459
00:18:33,840 --> 00:18:36,370
Iżda aktar konvinċenti,
onestament, ma 'dawn 19 chats,

460
00:18:36,370 --> 00:18:39,020
li kien aktar minn mod I
mistennija li jkollhom, kull wieħed minnhom

461
00:18:39,020 --> 00:18:41,370
10 minuta biex forsi
siegħa tul, tefgħet ukoll

462
00:18:41,370 --> 00:18:44,920
għad-dawl għadd ta 'kwistjonijiet dwar
kwistjonijiet familjari, kwistjonijiet ħabib,

463
00:18:44,920 --> 00:18:46,940
kwistjonijiet ta 'saħħa mentali
li aħna mbagħad impenjati,

464
00:18:46,940 --> 00:18:50,200
bl-istudent barka, resident
dekan, jew ħbieb, jew kwalunkwe numru ieħor

465
00:18:50,200 --> 00:18:51,450
tar-riżorsi ta 'appoġġ.

466
00:18:51,450 --> 00:18:54,454
Allura li din kienet tabilħaqq waħda
mill-aħjar użi ta 'żmienna

467
00:18:54,454 --> 00:18:55,870
u wieħed mill-interventi aħjar.

468
00:18:55,870 --> 00:18:58,870
>> Ma 'dak imsemmi, hija ma kellha ebda
input fuq ir-rata ta 'sejbien

469
00:18:58,870 --> 00:19:00,909
tal diżonestà akkademika b'mod aktar ġenerali.

470
00:19:00,909 --> 00:19:02,950
U jien DARE ngħid, f'dan is-sottogrupp
ta 'studenti li għaddiet sena

471
00:19:02,950 --> 00:19:06,350
kien demografiċi li għandna
qabel qatt identifikati qabel

472
00:19:06,350 --> 00:19:08,140
u qatt ma konness ma 'qabel.

473
00:19:08,140 --> 00:19:10,020
U għalhekk, dawn kienu
stejjer ta 'suċċess mill-isbaħ

474
00:19:10,020 --> 00:19:13,390
anki jekk dawn isiru apparenti
f'inqas minn ċirkostanzi ottimali.

475
00:19:13,390 --> 00:19:15,640
Allura, jżomm dan f'moħħu
kif inti tagħmel, forsi,

476
00:19:15,640 --> 00:19:17,390
xi deċiżjoni ħażina
yourself tard bil-lejl,

477
00:19:17,390 --> 00:19:20,151
li hemm rikors sakemm
kif l-istudent f'dik is-sitwazzjoni

478
00:19:20,151 --> 00:19:23,400
stess sa u tressaq sabiex inkunu nistgħu
jkollhom dan it-tip ta 'chat u jittrattaw dan

479
00:19:23,400 --> 00:19:27,310
b'mod li l-edukazzjoni, u mbagħad
nistgħu poġġih warajna l-għada.

480
00:19:27,310 --> 00:19:30,335
>> Allura mingħajr aktar dewmien, jieħdu l-
tarf off ta 'dan il-konverżazzjoni,

481
00:19:30,335 --> 00:19:35,080
r-raġuni l-ġriewi huma sa jiġifieri
biss biex jkisser is-silġ għal mument.

482
00:19:35,080 --> 00:19:39,560
U sfortunatament, dawn qed kollha irqad,
imma dak li kien suppost li jiġri hawn

483
00:19:39,560 --> 00:19:41,760
kien kulħadd kien suppost
li Awe u tip ta 'jirrilassaw

484
00:19:41,760 --> 00:19:43,910
wara din il-konverżazzjoni kbir ħafna.

485
00:19:43,910 --> 00:19:46,930
Imma apparentement Nressaq
l-ġriewi torqod.

486
00:19:46,930 --> 00:19:50,070
Imma jekk inti tmur l CS50
ġriewi mmejla websajt,

487
00:19:50,070 --> 00:19:51,610
inti tista 'tarahom kollha jum twil.

488
00:19:51,610 --> 00:19:55,280
Partikolarment forsi 02:00, jew
03:00, jew 04:00 bil-lejl

489
00:19:55,280 --> 00:19:57,480
biex tara eżenzjoni stress ftit hemmhekk.

490
00:19:57,480 --> 00:19:58,805
B'tali mod li huwa mmejla ġriewi.

491
00:19:58,805 --> 00:20:01,700

492
00:20:01,700 --> 00:20:02,200
Kull dritt.

493
00:20:02,200 --> 00:20:03,020
Ma kienx li gost?

494
00:20:03,020 --> 00:20:04,200
KOLLOX SEW.

495
00:20:04,200 --> 00:20:07,140
Allura, lura għal xi kompjuter
xjenza, jekk I jistgħu.

496
00:20:07,140 --> 00:20:10,600
>> Allura, ifakkar li l-aħħar darba bdejna
tħares mhux biss lejn prinċipali, li

497
00:20:10,600 --> 00:20:13,930
kien il-funzjoni default, l-meta
bandiera aħdar għafast ekwivalenti,

498
00:20:13,930 --> 00:20:16,999
imma aħna wkoll beda fil-qosor
miktub wħud mill-funzjonijiet tagħna stess.

499
00:20:16,999 --> 00:20:20,040
U s'issa ebda wieħed minn dawn il-funzjonijiet
kienu partikolarment kbar jew meaty.

500
00:20:20,040 --> 00:20:24,570
Int ser jsibu rwieħhom dawk akbar
funzjonijiet probabbilment, P sett 2, P sett 3,

501
00:20:24,570 --> 00:20:26,410
definittivament P sett 4 u onward.

502
00:20:26,410 --> 00:20:29,340
Dritt issa ħafna mill-programmi tiegħek,
jekk mhux kollha kemm huma, ċertament għal P

503
00:20:29,340 --> 00:20:31,550
sett 1 jista 'jsir kompletament prinċipali.

504
00:20:31,550 --> 00:20:33,810
Jekk programm tiegħek biss
ħames linji, 10 linji,

505
00:20:33,810 --> 00:20:37,070
anke 20 konzijiet, perfettament
raġonevoli biex tiktibha

506
00:20:37,070 --> 00:20:40,930
kollha prinċipali u mhux għal aktar minn jikkumplikaw
kodiċi tiegħek, imma dak li aħna qed tagħmel illum

507
00:20:40,930 --> 00:20:44,360
u quddiem qed tipprova wkoll
jintroduċi xi tekniki tad-disinn tajba

508
00:20:44,360 --> 00:20:48,660
sabiex bħala kodiċi tiegħek gets aktar
ikkumplikata u kif il-problemi

509
00:20:48,660 --> 00:20:51,690
inti tixtieq li issolvi jiksbu aktar diffiċli u
aktar interessanti ikollok, tip ta ',

510
00:20:51,690 --> 00:20:55,850
l-għodod fil-toolbox tiegħek magħhom
biex ifasslu soluzzjonijiet tajbin għal dawk.

511
00:20:55,850 --> 00:21:01,210
>> Allura, ejja tagħti ħarsa lura lejn
dan il-programm mill-aħħar ġimgħa tiegħi, li

512
00:21:01,210 --> 00:21:06,550
kien funzjonijiet żero dot C. U
Avviż li, pjuttost sempliċi,

513
00:21:06,550 --> 00:21:10,310
jidher qisu dan b'żewġ
funzjonijiet, prinċipali u l-isem print.

514
00:21:10,310 --> 00:21:13,160
U l-ħsieb lura jew forsi
inġinerija b'lura llum,

515
00:21:13,160 --> 00:21:16,880
dak li kien il-motivazzjoni għall-introduzzjoni
funzjoni konformi 28 imsejħa,

516
00:21:16,880 --> 00:21:18,180
Isem print?

517
00:21:18,180 --> 00:21:21,745
Jew dak li kien dan eżempju ta 'fil
rigward ta 'prinċipju jew takeaway,

518
00:21:21,745 --> 00:21:22,605
jekk inti.

519
00:21:22,605 --> 00:21:26,560

520
00:21:26,560 --> 00:21:27,300
Xi murmurs.

521
00:21:27,300 --> 00:21:28,830
Xiex?

522
00:21:28,830 --> 00:21:32,210
>> Yeah Dekompożizzjoni funzjonali hekk
huwa tip tal-mod fancy ta 'tgħid,

523
00:21:32,210 --> 00:21:34,690
jiddekomponu program tiegħek
fis-partijiet kostitwenti tiegħu

524
00:21:34,690 --> 00:21:37,530
u mbagħad jużaw dawk il-partijiet
biex tgħaqqad kollu.

525
00:21:37,530 --> 00:21:39,620
Allura, li wisq huwa biss tip
ta f'gidma diġà,

526
00:21:39,620 --> 00:21:42,050
iżda dan huwa forsi anke
Eżempju aħjar ta 'xi ħaġa

527
00:21:42,050 --> 00:21:43,081
biss imsejħa estrazzjoni.

528
00:21:43,081 --> 00:21:43,580
Dritt?

529
00:21:43,580 --> 00:21:46,950
Estrazzjoni se tkun waħda
mit-temi li baqgħu isiru fis CS50

530
00:21:46,950 --> 00:21:49,085
u wkoll kompjuter xjenza
b'mod aktar ġenerali peress li huwa

531
00:21:49,085 --> 00:21:53,060
teknika li magħhom inti tista 'ssolvi
problemi b'mod aktar effettiv għaliex inti

532
00:21:53,060 --> 00:21:56,807
jista 'jikteb soluzzjonijiet aktar
intuwittivament u b'mod li skali

533
00:21:56,807 --> 00:21:58,390
u hu mifhum minn nies oħra.

534
00:21:58,390 --> 00:21:59,860
What do I jfisser minn dak?

535
00:21:59,860 --> 00:22:04,340
>> Allura, forsi huwa ħafna aktar tinqara
li tħares lejn programm bħal dan,

536
00:22:04,340 --> 00:22:05,990
super qasir għalkemm huwa.

537
00:22:05,990 --> 00:22:10,050
Meta tara fuq il-linja 22 li hemm
funzjoni msejħa, l-isem print.

538
00:22:10,050 --> 00:22:12,620
Dak l-isem biss jgħid dak li tagħmel.

539
00:22:12,620 --> 00:22:15,780
Dik il-funzjoni apparentement tieħu
input bejn parentesi tagħha,

540
00:22:15,780 --> 00:22:18,600
u apparentement ma xi ħaġa,
preżumibbilment tistampa l-isem.

541
00:22:18,600 --> 00:22:20,880
U għalhekk, anke jekk aħna
assolutament jista 'jkollu

542
00:22:20,880 --> 00:22:25,280
isir dak li għamilna ġimgħa ilu, li kien
ħu din il-linja attwali ta 'kodiċi,

543
00:22:25,280 --> 00:22:28,710
teħles minn dan, u jiksbu
rid ta 'dan kollu flimkien,

544
00:22:28,710 --> 00:22:31,436
aħna tip ta 'estratt bogħod
il-kunċett ta 'stampar isem.

545
00:22:31,436 --> 00:22:33,060
I do not care jekk inti qed tuża def print.

546
00:22:33,060 --> 00:22:35,601
I do not care jekk għandek
mija S u backslash N. Dawn

547
00:22:35,601 --> 00:22:37,270
huma dettalji oerhört arcane.

548
00:22:37,270 --> 00:22:40,090
What I do kura dwar bħala
programmer hija istampar isem.

549
00:22:40,090 --> 00:22:43,414
U iva, liema aħjar mod biex tagħmel dan
minn billi ssejjaħ il-funzjoni, isem print?

550
00:22:43,414 --> 00:22:46,330
U hekk, li kienet waħda mill-motivazzjonijiet
biex isir xi ħaġa bħal din.

551
00:22:46,330 --> 00:22:50,370
Nagħmlu l-kodiċi jinqara aħjar, aktar
li jistgħu jerġgħu jintużaw, u wkoll awto deskrittiv.

552
00:22:50,370 --> 00:22:52,120
Issa, ejja tagħti ħarsa
fil eżempju ieħor,

553
00:22:52,120 --> 00:22:56,220
li kienet funzjoni waħda,
li kellna hawn fuq.

554
00:22:56,220 --> 00:23:00,367
>> Allura, dan huwa wieħed forsi aktar
konvinċenti għaliex, f'dan il-każ,

555
00:23:00,367 --> 00:23:01,700
Ma rridx li biss tikseb int.

556
00:23:01,700 --> 00:23:03,320
I rridu nġibu int pożittiv.

557
00:23:03,320 --> 00:23:06,470
U jirriżulta li tikseb pożittiv
int għandek tagħmel mazz ta legwork.

558
00:23:06,470 --> 00:23:06,969
Dritt?

559
00:23:06,969 --> 00:23:09,600
Mhuwiex linja waħda sempliċi
sejħa bħall-isem print kien,

560
00:23:09,600 --> 00:23:11,480
li huwa ċertament inqas konvinċenti.

561
00:23:11,480 --> 00:23:16,000
>> Biex tikseb int pożittiv, logically--
let me iscroll lura biex jaħbu dan.

562
00:23:16,000 --> 00:23:18,887
What do għandek tagħmel?

563
00:23:18,887 --> 00:23:20,720
Bħall-għodda kollha we
jkollhom fil-mument huma

564
00:23:20,720 --> 00:23:24,440
affarijiet simili stampati def minn Standard
Librerija u wkoll mil-librerija CS50

565
00:23:24,440 --> 00:23:26,990
għandna Get Int, u Get float,
Get Long Long, Get String,

566
00:23:26,990 --> 00:23:29,260
imma l-uniku wieħed, Germane,
dritt issa huwa Get Int.

567
00:23:29,260 --> 00:23:32,970
Allura, jekk l-unika għodda li għandek
fil-kaxxa għodda tiegħek huwa Get Int,

568
00:23:32,970 --> 00:23:35,505
kif do we go dwar implimentazzjoni
li tikseb int pożittiv?

569
00:23:35,505 --> 00:23:35,929
>> UDJENZA: Oħloq log u jivverifika
dwar jekk l-input li huma taw

570
00:23:35,929 --> 00:23:36,762
kienet pożittiva jew le.

571
00:23:36,762 --> 00:23:39,390

572
00:23:39,390 --> 00:23:40,640
>> SPEAKER 1: Perfect.

573
00:23:40,640 --> 00:23:41,200
Eżattament.

574
00:23:41,200 --> 00:23:43,950
Għodda oħra li għandna fil tagħna
toolbox minn ġimgħa jew tnejn ilu

575
00:23:43,950 --> 00:23:45,419
huwa biss il-kostruzzjoni looping.

576
00:23:45,419 --> 00:23:48,210
U għalhekk, yeah, jekk nużaw waqt
loop, jew do waqt loop, jew quddiem

577
00:23:48,210 --> 00:23:50,850
loop Nistgħu probabbilment jitbiegħed
ma 'kwalunkwe minn dawk f'xi forma.

578
00:23:50,850 --> 00:23:55,140
Aħna tista 'timplimenta l-kunċett ta' get
int pożittiva bi ftit użu Get Int,

579
00:23:55,140 --> 00:23:57,830
u mbagħad biss iżommu ssejjaħ dan
mill-ġdid u jżommu pestering-utent

580
00:23:57,830 --> 00:24:00,320
sakemm hu jew hi fil-fatt
tagħtina dak li rridu.

581
00:24:00,320 --> 00:24:03,260
>> U hekk issa, dan
estrazzjoni tal-proċess

582
00:24:03,260 --> 00:24:05,680
ta 'jkollna int pożittiva
fi funzjoni msejħa

583
00:24:05,680 --> 00:24:08,930
Get pożittiva Int huwa xi ftit aktar
konvinċenti għaliex tħares lejn din.

584
00:24:08,930 --> 00:24:10,990
Dawn huma simili 10 plus
linji ta 'kodiċi li

585
00:24:10,990 --> 00:24:15,090
huma involuti fil jkollna int pożittiva,
u jien ma verament kura kif inti tagħmel dan.

586
00:24:15,090 --> 00:24:17,850
All I-kura hija li inti
tista 'tagħmel dan, u għalhekk stajt

587
00:24:17,850 --> 00:24:21,660
moħbija dawn id-dettalji kollha wara
funzjoni msejħa Get pożittivi int li,

588
00:24:21,660 --> 00:24:23,430
tabilħaqq, għandha dan do filwaqt loop.

589
00:24:23,430 --> 00:24:27,660
>> U ara aħħar ġimgħa għall-sintassi
hemm, iżda hija biss jiddikjara N,

590
00:24:27,660 --> 00:24:29,800
u tistampa l-
istruzzjoni lill-utent.

591
00:24:29,800 --> 00:24:33,330
Huwa jappella Get Int u mbagħad din il-kontrolli
din il-kondizzjoni għal darb'oħra, u għal darb'oħra,

592
00:24:33,330 --> 00:24:35,230
u għal darb'oħra sakemm l-utent tikkoopera.

593
00:24:35,230 --> 00:24:38,000
>> Allura issa, għadd ta 'verifikazzjonijiet sanità ftit.

594
00:24:38,000 --> 00:24:40,370
Għal dawk familjari forsi
ma 'xi programmazzjoni,

595
00:24:40,370 --> 00:24:46,410
għaliex huwa N ddikjarat, għaliex għandi joħolqu
N barra tal-do filwaqt loop?

596
00:24:46,410 --> 00:24:50,370
Għaliex huwa fuq il-linja 29 u mhux
fuq bħal 33, per eżempju.

597
00:24:50,370 --> 00:24:53,529
>> UDJENZA: Għaliex meta inti
tiddikjaraha barra, it-tip

598
00:24:53,529 --> 00:24:56,688
ta 'aktar, il-scope-- akbar

599
00:24:56,688 --> 00:24:58,146
>> SPEAKER 1: Tajba.

600
00:24:58,146 --> 00:24:59,604
>> UDJENZA: --and jekk inti tiddikjara
ġewwa l-linja, [inaudible]

601
00:24:59,604 --> 00:25:00,979
minħabba li ma kinitx taf dwar dan.

602
00:25:00,979 --> 00:25:02,819

603
00:25:02,819 --> 00:25:03,610
SPEAKER 1: Eżattament.

604
00:25:03,610 --> 00:25:06,330
Jekk I tista 'simplify--
hija kwistjoni ta 'ambitu.

605
00:25:06,330 --> 00:25:11,530
U l-ambitu jirreferi għall-kuntest li
li varjabbli teżisti jew tkun tista 'tintuża.

606
00:25:11,530 --> 00:25:15,050
U l-istat sbieħ ta 'thumb hawnhekk huwa li
ġeneralment meta inti tiddikjara jew joħolqu

607
00:25:15,050 --> 00:25:21,642
varjabbli tista 'tuża biss dan ġewwa
tal-eqreb tħaddan braces kaboċċi.

608
00:25:21,642 --> 00:25:22,600
Allura dak li jfisser?

609
00:25:22,600 --> 00:25:26,551
Jekk I, minflok, jħoll dan u jmorru ma
xi ħaġa li jħoss ftit aktar sempliċi.

610
00:25:26,551 --> 00:25:27,050
Dritt?

611
00:25:27,050 --> 00:25:29,360
>> Linja 32 biss jistenna cleaner lili issa.

612
00:25:29,360 --> 00:25:31,500
Li qed nagħmel żewġ affarijiet fl
darba u mbagħad tassenja

613
00:25:31,500 --> 00:25:33,070
il-lemin li l-naħa tax-xellug.

614
00:25:33,070 --> 00:25:35,180
Il-problema issa msejsa fuq
dik id-definizzjoni ta 'ambitu

615
00:25:35,180 --> 00:25:41,130
huwa li N jistgħu jintużaw fil-linji
31 u 32 ġewwa ta 'dan loop,

616
00:25:41,130 --> 00:25:45,100
iżda fejn minn dik id-definizzjoni
jista 'ma jintuża?

617
00:25:45,100 --> 00:25:45,660
F'konformità liema?

618
00:25:45,660 --> 00:25:46,160
Yeah.

619
00:25:46,160 --> 00:25:47,490
>> UDJENZA: 35.

620
00:25:47,490 --> 00:25:49,180
>> SPEAKER 1: 35.

621
00:25:49,180 --> 00:25:50,480
Żgur li le 35.

622
00:25:50,480 --> 00:25:52,349
U wkoll fejn ħaddieħor?

623
00:25:52,349 --> 00:25:52,890
UDJENZA: 34.

624
00:25:52,890 --> 00:25:55,040
SPEAKER 1: Anke 34 huwa
problematika għaliex dan huwa

625
00:25:55,040 --> 00:25:56,450
barra taċ-ċingi kaboċċi.

626
00:25:56,450 --> 00:25:58,200
U għalhekk fil-fatt, ejja ara dak li jiġri.

627
00:25:58,200 --> 00:25:58,700
Dritt?

628
00:25:58,700 --> 00:26:00,722
Dan jista 'jidher ftit
intuwittivi jew jista 'ma jkunx,

629
00:26:00,722 --> 00:26:02,680
imma ejja ara dak l-
kompilatur li jgħidu meta

630
00:26:02,680 --> 00:26:04,730
immorru fis-direttorju sors lum.

631
00:26:04,730 --> 00:26:08,950
Jagħmlu funzjoni waħda.

632
00:26:08,950 --> 00:26:11,231
Oh, my god.

633
00:26:11,231 --> 00:26:12,980
Well, I finalment lest
li, mill-mod.

634
00:26:12,980 --> 00:26:14,030
Kull dritt.

635
00:26:14,030 --> 00:26:15,510
U x'inhu l-kwistjoni hawnhekk?

636
00:26:15,510 --> 00:26:17,430
Arcane ħafna li tħares lejn.

637
00:26:17,430 --> 00:26:19,570
Imma hawn hu dak I typed--
jagħmlu funzjoni waħda.

638
00:26:19,570 --> 00:26:21,640
Hawn dak jagħmel indotta,
li huwa attwalment

639
00:26:21,640 --> 00:26:23,705
bl-użu clang kompilatur
ma xi wħud minn dawk bnadar

640
00:26:23,705 --> 00:26:25,080
li aħna ser tara mill-ġdid qabel twil.

641
00:26:25,080 --> 00:26:26,829
U għal darb'oħra, dejjem tfittex
fl-ewwel żball,

642
00:26:26,829 --> 00:26:30,540
għaliex din tista 'biss ikollhom cascading
effett sens fuq linji oħra.

643
00:26:30,540 --> 00:26:34,410
>> Allura dak li dan ifisser huwa li l-
problema hija fil 1.c. funzjoni

644
00:26:34,410 --> 00:26:36,890
Huwa fuq il-linja 32.

645
00:26:36,890 --> 00:26:39,712
U huwa fuq kolonna, jew karattru, 13.

646
00:26:39,712 --> 00:26:42,670
Allura meta editur test tiegħek li jistgħu
jgħinek tidentifika fejn il-kwistjoni hija.

647
00:26:42,670 --> 00:26:47,079
Mela jekk jien iscroll, dak li huwa linja 32?

648
00:26:47,079 --> 00:26:49,120
Li fil-fatt dan wieħed
li diġà enfasizzat

649
00:26:49,120 --> 00:26:50,607
n varjabbli dritt here-- mhux użati.

650
00:26:50,607 --> 00:26:51,440
Imma din mhix mhux użati.

651
00:26:51,440 --> 00:26:52,320
Jien tużah.

652
00:26:52,320 --> 00:26:56,110
Iżda l-kumpilatur tal konfuż, minħabba
dan jeżisti biss ġewwa ta 'dan l-ambitu.

653
00:26:56,110 --> 00:26:57,727
U so I ma tistax tużah hawn.

654
00:26:57,727 --> 00:26:58,560
I ma tistax tużah hawn.

655
00:26:58,560 --> 00:27:01,320
U l-kumpilatur, għalhekk,
ma anki kura li nkun qiegħed nipprova.

656
00:27:01,320 --> 00:27:03,940
Jidher li jkun mhux użati
fl-ambitu reali tagħha.

657
00:27:03,940 --> 00:27:08,854
>> Allura nistgħu jespandu l-ambitu billi tagħmel
eżattament dak li bdejna with-- int n.

658
00:27:08,854 --> 00:27:11,020
U anki jekk ma
ħarsa eleganti, forsi,

659
00:27:11,020 --> 00:27:15,110
u aħna qed tieħu linja żejda
hawn, issa huwa fl-iskop kullimkien.

660
00:27:15,110 --> 00:27:15,970
Mela ejja erġa 'pprova.

661
00:27:15,970 --> 00:27:19,040
Sabiex tagħmel funzjoni waħda.

662
00:27:19,040 --> 00:27:19,610
Nizza.

663
00:27:19,610 --> 00:27:23,370
U issa jekk jien jekk I run funzjoni
waħda, ejja tagħtiha negattiva 10,

664
00:27:23,370 --> 00:27:27,170
negattiv 1, 0, 1, u tabilħaqq taħdem.

665
00:27:27,170 --> 00:27:28,610
>> Allura hemm soluzzjoni oħra hawn.

666
00:27:28,610 --> 00:27:29,280
Taf xiex?

667
00:27:29,280 --> 00:27:31,230
X'jiġri jekk I really am lotta ma 'dan?

668
00:27:31,230 --> 00:27:33,140
I do not know fejn l-
n suppost li jmorru.

669
00:27:33,140 --> 00:27:33,723
Taf xiex?

670
00:27:33,723 --> 00:27:39,220
Jien biss ser qiegħdu kollu l-
mod fil-quċċata tal-fajl tiegħi hawn.

671
00:27:39,220 --> 00:27:42,835
X'għandu dan do, do you think?

672
00:27:42,835 --> 00:27:43,335
Yeah?

673
00:27:43,335 --> 00:27:44,251
>> UDJENZA: [inaudible].

674
00:27:44,251 --> 00:27:47,964

675
00:27:47,964 --> 00:27:48,630
SPEAKER 1: Yeah.

676
00:27:48,630 --> 00:27:50,560
Hekk stajt għamilha globali, biex ngħidu hekk.

677
00:27:50,560 --> 00:27:54,430
Jekk ikollok xi varjabbli li l-barra
il-funzjonijiet kollha tiegħek li huwa permess,

678
00:27:54,430 --> 00:27:58,780
u l-kodiċi għandħa tfassal u n
issa se tkun aċċessibbli mhux biss jiksbu

679
00:27:58,780 --> 00:28:02,490
int pożittiva, iżda wkoll fil main-- li
huwa tħassib ftit għaliex hemm

680
00:28:02,490 --> 00:28:04,864
diġà n fil prinċipali, sabiex aktar
fuq dik fi ftit moment--

681
00:28:04,864 --> 00:28:06,530
iżda dan ikun ikkunsidrat disinn ħażin.

682
00:28:06,530 --> 00:28:06,910
Kull dritt.

683
00:28:06,910 --> 00:28:08,570
Jekk inti jkollhom jirrikorru għal
xi ħaġa simili, oh, I ser

684
00:28:08,570 --> 00:28:10,125
biss jitqiegħed up hawnhekk għaliex
il-kodiċi jidher li jikkompilaw

685
00:28:10,125 --> 00:28:12,180
huwa ġeneralment mhux l-aħjar prattika.

686
00:28:12,180 --> 00:28:14,590
Pjuttost inti tixtieq li tagħżel
l-ambitu idjaq possibbli

687
00:28:14,590 --> 00:28:18,720
għall-varjabbli tiegħek, li jfisser
jmorru ma 'disinn inizjali tagħna, li

688
00:28:18,720 --> 00:28:19,920
huwa dritt hawn.

689
00:28:19,920 --> 00:28:24,400
>> Issa bħala twarrib, jekk inti ma jkollhom
varjabbli identiku imsejjaħ hawn,

690
00:28:24,400 --> 00:28:27,750
il-mod c tieħu ħsieb this--
għalkemm dan mhux se jiġri wisq often--

691
00:28:27,750 --> 00:28:30,150
hija li dan għadu
perfettament multa hawn.

692
00:28:30,150 --> 00:28:35,000
Iżda din id-definizzjoni ta 'n konformi
22 se dell dik globali.

693
00:28:35,000 --> 00:28:38,190
Allura dan wieħed se jaħdmu fi ħdan
prinċipali, u l-wieħed globali

694
00:28:38,190 --> 00:28:41,670
fil-fatt se tapplika meta int fil
jiksbu int pożittiv Iżda aktar fuq li

695
00:28:41,670 --> 00:28:43,890
ieħor żmien, iżda biss
għal dawk kurjużi.

696
00:28:43,890 --> 00:28:45,970
>> Allura fil-qosor, aħna jiffissaw dan hawn.

697
00:28:45,970 --> 00:28:49,220
Issa ejja tease apparti żewġ biċċiet oħra
Qabel ma nħarsu lejn l-aħħar linja waħda tal-kodiċi

698
00:28:49,220 --> 00:28:50,170
f'dan il-programm.

699
00:28:50,170 --> 00:28:52,170
Get int pożittiv.

700
00:28:52,170 --> 00:28:54,450
Fuq in-naħa tax-xellug tal
kelma tiegħu huwa l-int kelma.

701
00:28:54,450 --> 00:28:56,860
Xi jfisser li turi taħseb?

702
00:28:56,860 --> 00:28:58,900
S'issa konna aktar tidher bla effett.

703
00:28:58,900 --> 00:28:59,400
Yeah?

704
00:28:59,400 --> 00:29:01,810
>> UDJENZA: Huwa t-tip ta '
varjabbli li inti qed tistaqsi dwar.

705
00:29:01,810 --> 00:29:04,550
>> SPEAKER 1: Yeah Hu l-tip ta ', let me
Ma jgħidux varjabbli, iżda t-tip ta 'valur

706
00:29:04,550 --> 00:29:05,990
li jien tistaqsi lura għall.

707
00:29:05,990 --> 00:29:08,070
U fil-fatt, li l-
intuwittivi hawn, wieħed jittama.

708
00:29:08,070 --> 00:29:08,200
Dritt?

709
00:29:08,200 --> 00:29:10,250
Jekk inti tixtieq li tikseb
int pożittiv, x'inhu inti

710
00:29:10,250 --> 00:29:12,920
jridu li l-function-- bħal tagħna
voluntiera minn ġimgħa li għaddiet

711
00:29:12,920 --> 00:29:15,720
lilek jagħtu lura biċċa
tal-karta ma 'int fuq dan?

712
00:29:15,720 --> 00:29:19,190
U hekk aħna ve speċifikat li l-
hekk imsejħa tip ritorn ta 'din il-funzjoni

713
00:29:19,190 --> 00:29:20,450
huwa li tikseb int pożittiv.

714
00:29:20,450 --> 00:29:22,990
Jekk aħna ma riedx li
ritorn xejn, inti tgħidli null.

715
00:29:22,990 --> 00:29:25,270
Jekk inti tixtieq li jirritornaw
string, inti tgħidli string.

716
00:29:25,270 --> 00:29:27,310
Jekk inti tixtieq li jirritornaw
a float, inti tgħidli float.

717
00:29:27,310 --> 00:29:30,440
Imma l-unika waħda li tapplika hawnhekk
loġikament, għaliex jien jużaw get int,

718
00:29:30,440 --> 00:29:34,130
anki jekk jien analiżi limitata għat
valuri pożittivi, huwa li jirritorna l int.

719
00:29:34,130 --> 00:29:38,380
>> Allura bil-maqlub, xi jfisser
li hemm vojt fil-parentesi?

720
00:29:38,380 --> 00:29:40,130
What do l-parentesi
ġeneralment jiddefinixxi?

721
00:29:40,130 --> 00:29:40,588
Yeah?

722
00:29:40,588 --> 00:29:42,880
>> UDJENZA: Dan ifisser l-funzjoni tal
ma attwalment jkollna dan.

723
00:29:42,880 --> 00:29:44,650
>> SPEAKER 1: Dan ifisser l-funzjoni tal
ma attwalment jkollna dak?

724
00:29:44,650 --> 00:29:45,430
>> UDJENZA: An input.

725
00:29:45,430 --> 00:29:46,763
>> SPEAKER 1: An input, tkun xi tkun.

726
00:29:46,763 --> 00:29:49,870
Allura fil-fatt, jekk parentesi
hawn inti tispeċifika null,

727
00:29:49,870 --> 00:29:51,650
li biss ifisser jien ma tridx xi input.

728
00:29:51,650 --> 00:29:53,269
I ser tittratta l-problema myself.

729
00:29:53,269 --> 00:29:55,810
U fil-fatt, inti ma għandekx
tell tikseb xejn int pożittiv.

730
00:29:55,810 --> 00:29:59,630
Inti biss jgħidu, nikseb int pożittiv, u li
funzjoni se jmorru off u tagħmel ħaġa tagħha.

731
00:29:59,630 --> 00:30:02,970
>> Iżda hemm kien trick ftit stajt
ġiet playing hawn dan iż-żmien kollu

732
00:30:02,970 --> 00:30:04,970
biex tiżgura dan il-kodiċi jikkompila.

733
00:30:04,970 --> 00:30:09,620
Avviż li int-- tikseb pożittiv
void-- int tibda tintuża 27.

734
00:30:09,620 --> 00:30:14,530
Iżda għal xi raġuni apparentement stramb
huwa wkoll up here fuq il-linja 16.

735
00:30:14,530 --> 00:30:18,530
U biss għal miżura tajba I ser jirrepeti
dan hekk huwa perfettament identiċi.

736
00:30:18,530 --> 00:30:21,640
U stajt qal prototip ma
ftit kumment wieħed-line.

737
00:30:21,640 --> 00:30:28,850
X'jiġri jekk I tħassar li, And
issa terġa jagħmlu funzjoni 1, jidħlu.

738
00:30:28,850 --> 00:30:29,350
Whoops.

739
00:30:29,350 --> 00:30:32,527

740
00:30:32,527 --> 00:30:33,110
Stenna minuta.

741
00:30:33,110 --> 00:30:34,764
Fejn hi tab tiegħi?

742
00:30:34,764 --> 00:30:35,263
Huh?

743
00:30:35,263 --> 00:30:37,969

744
00:30:37,969 --> 00:30:39,620
Standby.

745
00:30:39,620 --> 00:30:41,570
Jagħmlu funzjoni 1.

746
00:30:41,570 --> 00:30:42,150
Hemm immorru.

747
00:30:42,150 --> 00:30:42,310
KOLLOX SEW.

748
00:30:42,310 --> 00:30:43,400
Kieku ma meħlusin suppost.

749
00:30:43,400 --> 00:30:45,220
So, I think hemm ftit
bug hawn fejn jien ma

750
00:30:45,220 --> 00:30:46,636
jaraw l-isem tab fil-mument.

751
00:30:46,636 --> 00:30:47,940
Allura dak li qed jiġri hawn?

752
00:30:47,940 --> 00:30:52,210
Dikjarazzjoni impliċitu tal-funzjoni
nikseb int pożittiv huwa invalidu C99.

753
00:30:52,210 --> 00:30:53,940
Għalhekk għal darb'oħra konfuża.

754
00:30:53,940 --> 00:30:55,200
Allura dak li huwa dan indikattiva ta '?

755
00:30:55,200 --> 00:30:57,287
Ukoll, jirriżulta li
C huwa pretty stupid.

756
00:30:57,287 --> 00:30:59,912
Ukoll, huwa l-ipprogrammar
lingwa, jew pjuttost il-kompilatur hu.

757
00:30:59,912 --> 00:31:02,940
Huwa biss jaf dak li għandek
mgħallma, u huwa biss

758
00:31:02,940 --> 00:31:05,640
ser tkun taf xi ħaġa
jekk inti mgħallma qabel.

759
00:31:05,640 --> 00:31:07,960
Fi kliem ieħor, fil
prinċipali fil-mument, jien

760
00:31:07,960 --> 00:31:10,900
jippruvaw li jsejjaħ il-funzjoni
imsejħa tikseb int pożittiv.

761
00:31:10,900 --> 00:31:14,120
Iżda l-kumpilatur mhux se
l-avviż li tikseb int pożittiv

762
00:31:14,120 --> 00:31:16,500
teżisti sakemm linja 26.

763
00:31:16,500 --> 00:31:21,360
U għalhekk dak l-kumpilatur ma huwa biss
Żbalji hekk kif jiġrilha għal-linja 17,

764
00:31:21,360 --> 00:31:23,700
qal dikjarazzjoni impliċitu
tal nikseb int pożittiv, li

765
00:31:23,700 --> 00:31:27,740
huwa biss mod fancy ta 'tgħid, jien ma
jafu liema jiksbu int pożittiv huwa għadu.

766
00:31:27,740 --> 00:31:31,240
>> Lingwi oħra bħall Java u
Python u Ruby tista 'tidher quddiem.

767
00:31:31,240 --> 00:31:32,240
C ma.

768
00:31:32,240 --> 00:31:35,110
U għalhekk l-mod infasslu
dan huwa wieħed minn żewġ modi.

769
00:31:35,110 --> 00:31:40,160
Jew wieħed, jekk il-problema hija li tikseb
int pożittiva ma deherx li kien qabel,

770
00:31:40,160 --> 00:31:42,150
Well, let me biss jimxu lill-quċċata.

771
00:31:42,150 --> 00:31:43,650
Li tiffissa din il-problema.

772
00:31:43,650 --> 00:31:46,790
Iżda ġeneralment, huwa
kkunsidrati aħjar teknika

773
00:31:46,790 --> 00:31:50,220
li jpoġġu funzjoni prinċipali tiegħek fil-ħafna
top b'tali mod li bniedem qari kodiċi tiegħek

774
00:31:50,220 --> 00:31:52,710
jaf dak il-programm ma,
minħabba prinċipali ma tiġix midfun kollha

775
00:31:52,710 --> 00:31:53,960
il-mod fil-qiegħ jew fin-nofs.

776
00:31:53,960 --> 00:31:55,130
Huwa fuq nett.

777
00:31:55,130 --> 00:31:56,410
Allura li ma jħossx ideali.

778
00:31:56,410 --> 00:31:58,326
U inti tista 'attwalment tikseb
fis-sitwazzjonijiet fejn

779
00:31:58,326 --> 00:32:00,820
jekk sejħiet funzjoni waħda
ieħor, li titlob oħra,

780
00:32:00,820 --> 00:32:04,630
tista 'tikseb fis kwistjoni fejn la
tista 'tmur fuq l-oħra, loġikament.

781
00:32:04,630 --> 00:32:05,920
Huwa biss mhux possibbli.

782
00:32:05,920 --> 00:32:09,290
>> U għalhekk l-mod biex jaħdmu
madwar dan huwa li jieħdu biss

783
00:32:09,290 --> 00:32:13,200
firma tal-funzjoni ta, biex speak--
l-ewwel linja fejn huwa declared--

784
00:32:13,200 --> 00:32:16,850
u biss kopja, paste fil-
top, iżda mhux ma 'kaboċċi braces--

785
00:32:16,850 --> 00:32:17,980
biss ma 'virgola.

786
00:32:17,980 --> 00:32:20,840
Huwa simili ħjiel ftit
ta 'dak li ġejjin.

787
00:32:20,840 --> 00:32:26,630
U fil-fatt, kollha ta 'dan iż-żmien meta aħna
raw affarijiet simili io.h standard

788
00:32:26,630 --> 00:32:33,040
u cs50.h, b'mod simili, f'dawk dot
fajls h hemm prototipi oħra.

789
00:32:33,040 --> 00:32:35,250
U aħna ser tara li qabel twil.

790
00:32:35,250 --> 00:32:39,340
>> Allura fil-qosor, meta jkollok program
fil-fajl ma 'bosta funzjonijiet

791
00:32:39,340 --> 00:32:42,300
minbarra prinċipali, inti kważi
dejjem tixtieq li jiddikjaraw lilhom

792
00:32:42,300 --> 00:32:45,360
biss permezz ta 'l-ewwel tagħhom
linja, segwit b'waqfa u virgola,

793
00:32:45,360 --> 00:32:48,410
fuq nett tal-fajl.

794
00:32:48,410 --> 00:32:50,460
Dan kien ħafna kollha f'daqqa.

795
00:32:50,460 --> 00:32:53,130
Kwalunkwe mistoqsijiet?

796
00:32:53,130 --> 00:32:53,920
Kwalunkwe mistoqsijiet?

797
00:32:53,920 --> 00:32:54,530
Kull dritt.

798
00:32:54,530 --> 00:32:59,760
>> Mela ejja jimxu fuq imbagħad
għal xi ħaġa bħal sogħla.

799
00:32:59,760 --> 00:33:00,260
Oh.

800
00:33:00,260 --> 00:33:00,570
Kif twaħħil.

801
00:33:00,570 --> 00:33:01,220
Kull dritt.

802
00:33:01,220 --> 00:33:02,260
Sogħla.

803
00:33:02,260 --> 00:33:05,080
Allura hawnhekk huwa ċ
implimentazzjoni ta 'programm

804
00:33:05,080 --> 00:33:07,560
għamilna l-oħra jum fil
Scratch li ħafna sempliċement biss

805
00:33:07,560 --> 00:33:08,691
jgħid sogħla, sogħla, sogħla.

806
00:33:08,691 --> 00:33:09,190
Kull dritt.

807
00:33:09,190 --> 00:33:11,136
U xi ħadd qal ftit
jiem ilu li hemm

808
00:33:11,136 --> 00:33:12,760
mod ta 'tindif dan il-kodiċi up diġà.

809
00:33:12,760 --> 00:33:12,880
Kull dritt?

810
00:33:12,880 --> 00:33:15,440
Hekk kif int ikkupjar u
pasta disinn probabbilment ħażin.

811
00:33:15,440 --> 00:33:18,725
Mill-inqas darba irridu jiksbu l erba 'jew ħames
jew 20 sogħla, iħoss prattika ħażina.

812
00:33:18,725 --> 00:33:19,850
Aħna biss iżommu kopja, pasta.

813
00:33:19,850 --> 00:33:22,213
X'hemm-soluzzjoni ovvja
biex tnaddafhom dan il-programm up?

814
00:33:22,213 --> 00:33:23,120
>> UDJENZA: Loop.

815
00:33:23,120 --> 00:33:23,350
>> SPEAKER 1: Yeah.

816
00:33:23,350 --> 00:33:24,070
Allura l-użu ta 'loop.

817
00:33:24,070 --> 00:33:27,697
U aħna jistgħu jużaw għall-loop, filwaqt
loop, kull numru ta 'approċċi.

818
00:33:27,697 --> 00:33:29,780
U fil-fatt, dan huwa dak
nagħmlu fil-verżjoni wieħed hawn.

819
00:33:29,780 --> 00:33:32,250
Stajt minflok miktuba mill-ġdid it
fil-verżjoni wieħed mill cough.c

820
00:33:32,250 --> 00:33:35,170
li jkun biss sogħla fi għar-loop.

821
00:33:35,170 --> 00:33:38,240
Id-dritt, imma hemm xi
opportunità issa biex tip ta 'start

822
00:33:38,240 --> 00:33:41,630
għal disinn din ftit aktar simili
il lezzjoni aħna mgħallma mument ilu,

823
00:33:41,630 --> 00:33:46,190
li hija this-- jissoponi li xtaqt
li toħloq funzjoni msejħa sogħla,

824
00:33:46,190 --> 00:33:49,730
ejja jikkunsidraw għal ftit mument
dak li għaddej biex look like.

825
00:33:49,730 --> 00:33:51,900
Mela jekk irrid xi ħaġa
sogħla, I biss bżonn

826
00:33:51,900 --> 00:33:53,800
tuża print f ġewwa l-funzjoni.

827
00:33:53,800 --> 00:33:55,030
U tabilħaqq I am.

828
00:33:55,030 --> 00:33:56,990
U fil-fatt, dan kollu
żmien, kwalunkwe ħin int

829
00:33:56,990 --> 00:33:59,000
istampar xi ħaġa li
l-iskrin, programmer

830
00:33:59,000 --> 00:34:00,610
kieku ssejjaħ li effett sekondarju.

831
00:34:00,610 --> 00:34:02,990
Mhuwiex me għoti
lura xi ħadd valur.

832
00:34:02,990 --> 00:34:06,170
Huwa me tieħu xi azzjoni
li jista 'jkun viżwalment evidenti.

833
00:34:06,170 --> 00:34:10,672
Iżda dan sogħla funzjoni, ma ritorn
xejn bbażata fuq l-ewwel linja tagħha?

834
00:34:10,672 --> 00:34:12,880
Le, għaliex it-tip ta 'ritorn tagħha
huwa null, li ifisser biss

835
00:34:12,880 --> 00:34:14,250
mhuwiex għoti me xejn lura.

836
00:34:14,250 --> 00:34:16,791
Dan jista 'jkun tagħmel xi ħaġa
viżwalment, iżda mhuwiex għoti me

837
00:34:16,791 --> 00:34:18,639
lura biċċa karta simili ġimgħa li għaddiet.

838
00:34:18,639 --> 00:34:21,310
>> Ma bżonn xi input?

839
00:34:21,310 --> 00:34:21,810
No

840
00:34:21,810 --> 00:34:23,134
U dan huwa bla effett hawnhekk ukoll.

841
00:34:23,134 --> 00:34:25,600
Allura dan ukoll huwa tip ta
over-inġinerija din il-problema.

842
00:34:25,600 --> 00:34:26,099
Dritt?

843
00:34:26,099 --> 00:34:28,820
Stajt għamel il-programm aktar
kumplessi, aktar linji ta 'kodiċi,

844
00:34:28,820 --> 00:34:31,889
I ma jkunux għamlu dan xi
aktar funzjonali, iżda dan

845
00:34:31,889 --> 00:34:34,210
tkun sies,
forsi, għal usa

846
00:34:34,210 --> 00:34:36,830
kuntest bil-kodiċi aktar ikkumplikat.

847
00:34:36,830 --> 00:34:38,150
Imma xi ngħidu dwar dan?

848
00:34:38,150 --> 00:34:42,050
Liema kienu I done-- biss glancing fil
dan mingħajr ma jħares lejn il-kumment

849
00:34:42,050 --> 00:34:46,076
fuq nett tal-file-- dak jkollha
I fundamentalment jsir hawn ma sogħla tiegħi

850
00:34:46,076 --> 00:34:47,409
implimentazzjoni li l differenti?

851
00:34:47,409 --> 00:34:48,327
Yeah, fid-dahar?

852
00:34:48,327 --> 00:34:51,384
>> UDJENZA: Jagħmluha sabiex inti tista '
ikollhom karattru itfi.

853
00:34:51,384 --> 00:34:52,050
SPEAKER 1: Yeah.

854
00:34:52,050 --> 00:34:53,270
Allura dan iħoss tip ta 'sbieħ.

855
00:34:53,270 --> 00:34:53,389
Dritt?

856
00:34:53,389 --> 00:34:56,600
Huwa simili żżid karatteristika li tiegħek
programm jew il-funzjoni tiegħek, f'dan il-każ.

857
00:34:56,600 --> 00:34:57,830
Hija xorta prospetti xejn.

858
00:34:57,830 --> 00:35:00,538
Jista 'jkollha effett sekondarju viżwali,
għaliex dan huwa sejħa print f.

859
00:35:00,538 --> 00:35:02,800
Imma issa jien parametrized
il-funzjoni, li

860
00:35:02,800 --> 00:35:06,470
tfisser Stajt kien jispeċifika meħuda
input ta 'int tip u sejħa hija n,

861
00:35:06,470 --> 00:35:08,510
imma I jistgħu sejħa hija xi ħaġa nixtieq.

862
00:35:08,510 --> 00:35:11,550
Fil-fatt, jista 'jkun biss
ħinijiet li jkunu aktar espliċiti.

863
00:35:11,550 --> 00:35:13,310
U allura I jistgħu biss tbiddel dan hawn.

864
00:35:13,310 --> 00:35:16,450
Imma l-punt hu li dan huwa kif I
toħloq funzjoni li jieħu input.

865
00:35:16,450 --> 00:35:19,530
U jekk inti recall flipping
permezz forsi online f'wieħed

866
00:35:19,530 --> 00:35:23,000
mill-throughs jimxu, l-
raba 'u l-eżempju sogħla finali,

867
00:35:23,000 --> 00:35:27,150
tkun taf Avviż hawn stajt ġeneralizzati
kodiċi tiegħi tip further-- ta estratt

868
00:35:27,150 --> 00:35:27,690
aktar.

869
00:35:27,690 --> 00:35:31,390
Bħal sogħla u tgħatas, it-tnejn huma
dwar simili qal xi ħaġa jew jagħmlu

870
00:35:31,390 --> 00:35:32,330
xi tip ta 'ħoss.

871
00:35:32,330 --> 00:35:34,725
Save ikun il-
blokk Scratch korrispondenti.

872
00:35:34,725 --> 00:35:37,350
U hekk dak li għamilt f'dan il-verżjoni,
li nistgħu biss t'għajn fil-

873
00:35:37,350 --> 00:35:43,170
huwa sogħla huwa biss simili qal, [SOGĦLA],
sogħla, u sadanittant, għatis huwa

874
00:35:43,170 --> 00:35:44,570
simili qal, [ACHOO].

875
00:35:44,570 --> 00:35:46,900
U hekk stajt ġeneralizzati
l-implimentazzjoni ta 'dawk

876
00:35:46,900 --> 00:35:48,970
minn issa implimentazzjoni
din il-funzjoni ġenerika,

877
00:35:48,970 --> 00:35:51,490
jgħidu, li huwa interessanti
għal skopijiet lum

878
00:35:51,490 --> 00:35:54,300
biss minħabba li għadu
ma jkollux tip ta 'ritorn.

879
00:35:54,300 --> 00:35:56,398
Imma kemm inputs ma jkollu?

880
00:35:56,398 --> 00:35:56,981
UDJENZA: Żewġ.

881
00:35:56,981 --> 00:35:57,430
SPEAKER 1: Żewġ.

882
00:35:57,430 --> 00:35:59,263
U hekk jekk inti tixtieq li
jieħdu żewġ argumenti,

883
00:35:59,263 --> 00:36:00,710
biss ikunu separati b'virgola.

884
00:36:00,710 --> 00:36:03,110
U jekk inti tixtieq li mbagħad
sejħa dik il-funzjoni,

885
00:36:03,110 --> 00:36:05,800
avviż li inti biss
sejħa jiġifieri, kwotazzjoni, unquote,

886
00:36:05,800 --> 00:36:09,090
għall-ewwel argument, komuni
n, għat-tieni argument.

887
00:36:09,090 --> 00:36:12,130
Għalhekk għal darb'oħra, aħna biss għandhom issa l-
blokki tal-bini sabiex inkunu nistgħu attwalment

888
00:36:12,130 --> 00:36:15,686
jimplimentaw wħud mill-funzjonijiet tagħna stess.

889
00:36:15,686 --> 00:36:16,570
Kull dritt.

890
00:36:16,570 --> 00:36:19,690
Kwalunkwe mistoqsijiet dwar dawn?

891
00:36:19,690 --> 00:36:22,400
>> Allura issa ejja qoxra lura saff jekk iva.

892
00:36:22,400 --> 00:36:24,840
U l-għan, finalment,
huwa sett problema ġimgħa d-dieħla

893
00:36:24,840 --> 00:36:27,710
se tkun fuq cryptogrophy--
l-arti tal scrambling informazzjoni.

894
00:36:27,710 --> 00:36:30,640
U speċifikament, l-informazzjoni
se jkollhom inti kriptaġġ jew decrypt

895
00:36:30,640 --> 00:36:31,605
se tkun test.

896
00:36:31,605 --> 00:36:33,980
U għalhekk dak it-tip ta tistieden
il-kwistjoni tal-lum simili sew,

897
00:36:33,980 --> 00:36:38,480
dak li qed jiġri taħt il-barnuża
b'test lil hinn ASCII minn żero ġimgħa,

898
00:36:38,480 --> 00:36:40,730
u kif nistgħu attwalment
tibda jimmanipulaw dan?

899
00:36:40,730 --> 00:36:43,070
Allura hawnhekk huwa l-isem Zamyla tal.

900
00:36:43,070 --> 00:36:47,380
U fit-test, li jistgħu jiġu inputted
fil bħall-funzjoni get sekwenza.

901
00:36:47,380 --> 00:36:52,540
U l-bidu issa, meta inti tara
string bħal this-- Z-A-M-Y-L-A--

902
00:36:52,540 --> 00:36:56,550
tibda taħseb li bħala għalkemm kull
ta 'dawk il-karattri hija f'kaxxa tagħha

903
00:36:56,550 --> 00:36:57,050
stess.

904
00:36:57,050 --> 00:36:59,460
U fil-fatt, fil-ġimgħa jew hekk huwa
ħin, kull wieħed minn dawn il-kaxxi

905
00:36:59,460 --> 00:37:04,280
se jirrappreżenta ħafna speċifikament
blokk ta memory-- gidma ta 'memorja.

906
00:37:04,280 --> 00:37:07,050
Allura kull wieħed minn dawn l-ittri,
finalment, se jirrappreżentaw 8 bits.

907
00:37:07,050 --> 00:37:10,560
U aħna ser verament tara x'inhu għaddej
fuq taħt il-barnuża fil-kompjuter tiegħi.

908
00:37:10,560 --> 00:37:13,440
>> Iżda għal mhux huwa biżżejjed
biss li tħares lejn Zamyla

909
00:37:13,440 --> 00:37:17,520
permezz ta 'dan lenti, fejn kull wieħed mis
dawn l-ittri huwa fil-kaxxa tiegħu stess.

910
00:37:17,520 --> 00:37:22,697
U nicely biżżejjed C nistgħu
aċċess kull wieħed minn dawn il-kaxxi direttament.

911
00:37:22,697 --> 00:37:25,530
Mela jekk inti tixtieq li tikseb l-ewwel
ittra ta 'isem tagħha, super faċli fil C.

912
00:37:25,530 --> 00:37:28,410
Jekk inti tixtieq li tikseb l-aħħar
ittra, super faċli kif ukoll

913
00:37:28,410 --> 00:37:30,240
ma 'biċċa ta' sintassi ġdida.

914
00:37:30,240 --> 00:37:36,250
>> Hekk jien ser jimxi 'l quddiem fis CS50
IDE u tiftaħ is-sekwenza żero dot C.

915
00:37:36,250 --> 00:37:40,270
U f'dan l-eżempju hawn, hemm
ftit affarijiet ġodda għaddejjin.

916
00:37:40,270 --> 00:37:44,360
Allura l-ewwel fil-linja 19, konna
rajt dan string get before--.

917
00:37:44,360 --> 00:37:49,840
Hekk biss bħala kontroll sanità malajr,
jekk xi ħadd jista 'joffri up verbalment

918
00:37:49,840 --> 00:37:52,662
ispjegazzjoni layman ta
x'inhu għaddej fil-linja 19.

919
00:37:52,662 --> 00:37:55,370
Bħal biss tittraduċi dan in
Ingliż li roommate mhux fil CS50

920
00:37:55,370 --> 00:37:56,416
jista jifhmu.

921
00:37:56,416 --> 00:37:56,916
Yeah.

922
00:37:56,916 --> 00:37:59,749
>> UDJENZA: Ittieħdu l-input utent
spag u jaħżnu varjabbli s.

923
00:37:59,749 --> 00:38:01,934

924
00:38:01,934 --> 00:38:02,600
SPEAKER 1: Tajba.

925
00:38:02,600 --> 00:38:05,579
Ittieħdu l-input utent string
u jaħżen fil varjabbli s.

926
00:38:05,579 --> 00:38:06,120
Li l-kbir.

927
00:38:06,120 --> 00:38:08,090
Allura fuq il-lemin
naħa, nagħmlu sejħa get sekwenza.

928
00:38:08,090 --> 00:38:10,340
Li jirritorna valur
li ma jiksbu assenjat

929
00:38:10,340 --> 00:38:14,230
minn naħa tal-lemin to-xellug idejn
naħa ġo varjabbli msejħa s thats

930
00:38:14,230 --> 00:38:15,950
maħsuba biex jaħżnu string.

931
00:38:15,950 --> 00:38:16,800
Eżattament.

932
00:38:16,800 --> 00:38:20,000
>> Allura issa linja 22, kull
l-kumment fil-linja 21,

933
00:38:20,000 --> 00:38:22,780
ovvjament stampi li string
karattru wieħed kull linja.

934
00:38:22,780 --> 00:38:23,740
Imma kif?

935
00:38:23,740 --> 00:38:27,040
Allura l-ewwel nett, aħna initialize I għal 0.

936
00:38:27,040 --> 00:38:31,061
U allura kif nistgħu jiksbu l
l-aħħar tal-isem Zamyla ta?

937
00:38:31,061 --> 00:38:32,810
Ukoll, fl-aħħar tal
Isem Zamyla, jiena tista

938
00:38:32,810 --> 00:38:38,151
manwalment tip fl-aħħar karattru ta '
isem tagħha b'xi mod, jew in-numru ta 'dan.

939
00:38:38,151 --> 00:38:38,650
Dritt?

940
00:38:38,650 --> 00:38:43,500
Jekk immorru lura here-- Z-A-M-L--
Y-L-A-- so I tista 'tip fil.

941
00:38:43,500 --> 00:38:47,340
X'inhu l-indiċi tal
Aħħar ittra Zamyla tal?

942
00:38:47,340 --> 00:38:52,517
Jekk dan huwa 0-- jitkellem bħal
programmer-- 0, 1, 2, 3, 4, 5,

943
00:38:52,517 --> 00:38:56,570
I heard-- hekk tabilħaqq, l-aħħar ittra
fl-isem Zamyla huwa s-sitt,

944
00:38:56,570 --> 00:38:58,890
imma jekk aħna għadd minn 0,
li għaddej biex tkun numru 5.

945
00:38:58,890 --> 00:39:01,320
Sabiex iżommu dan f'moħħhom hawn.

946
00:39:01,320 --> 00:39:04,929
>> Jirriżulta hemm funzjoni fl
C imsejħa strlen, u lura fil-ġurnata

947
00:39:04,929 --> 00:39:06,720
u din il-ġurnata għadu,
ħafna ta 'programmaturi

948
00:39:06,720 --> 00:39:09,524
jagħżlu sinkronizzazzjoni tas ismijiet għall tagħhom
funzjonijiet li ħoss bħal l-kliem

949
00:39:09,524 --> 00:39:10,440
dawn qed nipprova ngħid.

950
00:39:10,440 --> 00:39:12,590
Allura strlen huwa t-tul sekwenza.

951
00:39:12,590 --> 00:39:18,168
U iva, liema kieku tul sensiela ta '
S ritorn meta Zamyla huwa l-input?

952
00:39:18,168 --> 00:39:19,569
>> UDJENZA: Five.

953
00:39:19,569 --> 00:39:22,090
>> SPEAKER 1: Z-A-M-Y-L. Sitt.

954
00:39:22,090 --> 00:39:22,590
Dritt?

955
00:39:22,590 --> 00:39:23,940
X'inhu l-tul ta 'isem Zamyla ta?

956
00:39:23,940 --> 00:39:24,440
Dritt?

957
00:39:24,440 --> 00:39:26,240
U biss fir-realtà, sitt ittri.

958
00:39:26,240 --> 00:39:26,740
Dritt?

959
00:39:26,740 --> 00:39:28,940
U hekk xi jfisser għall loop tagħna?

960
00:39:28,940 --> 00:39:32,130
Aħna qed tmur biex tmur minn
0 sa sitt, li

961
00:39:32,130 --> 00:39:33,650
se tagħtina ħames iterazzjonijiet.

962
00:39:33,650 --> 00:39:34,890
X'nagħmlu fuq kull iterazzjoni?

963
00:39:34,890 --> 00:39:36,870
Ukoll, mija C, xi ħadd
guessed l-oħra jum,

964
00:39:36,870 --> 00:39:38,710
tfisser placeholder għal liema?

965
00:39:38,710 --> 00:39:39,335
>> UDJENZA: Char.

966
00:39:39,335 --> 00:39:40,293
SPEAKER 1: Just a char.

967
00:39:40,293 --> 00:39:42,877
Allura character-- waħda ma
karattri multipli bħal string.

968
00:39:42,877 --> 00:39:45,251
U allura hawnhekk l-linja l-ġdida
li konna ltqajna istampar out.

969
00:39:45,251 --> 00:39:46,580
U allura hawnhekk l-sintassi ġdida.

970
00:39:46,580 --> 00:39:51,130
Jekk inti tixtieq li jistampa l-i-th
karattru fis-sekwenza S, biex ngħidu hekk,

971
00:39:51,130 --> 00:39:54,060
inti tista 'sempliċement jgħidu l
isem tas-sekwenza S,

972
00:39:54,060 --> 00:39:58,230
u mbagħad iftaħ parentesi kwadra, u
imbagħad magħluqa parentesi kwadra, bi i

973
00:39:58,230 --> 00:39:58,780
-nofs.

974
00:39:58,780 --> 00:40:01,430
U huwa tip ta 'sbieħ f'dak
dan it-tip ta qisu kwadru

975
00:40:01,430 --> 00:40:06,210
bħad-kwadri li fihom l Zamyla
jeżistu karattri fuq dik stampa hemmhekk.

976
00:40:06,210 --> 00:40:09,970
>> Mela jekk I attwalment imexxu dan
issa, ejja ara dak li jiġri.

977
00:40:09,970 --> 00:40:15,190
Jagħmlu string 0 dot slash
string 0, u allura jien

978
00:40:15,190 --> 00:40:16,720
ser tip fl-isem Zamyla tal.

979
00:40:16,720 --> 00:40:19,428
M'hemm l-ebda pront, minħabba I ma
użu print f, iżda li l-multa.

980
00:40:19,428 --> 00:40:20,660
I biss jafu x'għandhom jagħmlu.

981
00:40:20,660 --> 00:40:23,240
U fil-fatt, prints out
Isem Zamyla, l waħda għal kull linja.

982
00:40:23,240 --> 00:40:25,760
>> Issa ejja tkun ftit imprudenti.

983
00:40:25,760 --> 00:40:28,461
Ejja ngħidu li ma kontx naf
dwar strlen u I dehret,

984
00:40:28,461 --> 00:40:31,460
id-dritt, l-ebda wieħed għaddej biex ikollhom
isem akbar minn like 50 karattru.

985
00:40:31,460 --> 00:40:36,360
Ejja imorru quddiem u recompile dan
u terġa 'ssir, u mbagħad it-tip fil Zamyla

986
00:40:36,360 --> 00:40:37,160
mill-ġdid.

987
00:40:37,160 --> 00:40:40,850
Loġikament, dak li huwa l-
programm ser jippruvaw li jistampaw?

988
00:40:40,850 --> 00:40:49,545
Z-A-M--Y L-A imbagħad like 45
bytes mhux magħrufa tal-memorja.

989
00:40:49,545 --> 00:40:51,670
U fil-fatt, aħna ser terga 'lura
għal din l-idea ta 'memorja.

990
00:40:51,670 --> 00:40:54,180
Iżda biss loġikament, jekk
Isem Zamyla huwa dan twil,

991
00:40:54,180 --> 00:40:56,450
kif kull l-istampa
hawn, dak li aħna qed tgħid

992
00:40:56,450 --> 00:40:59,810
huwa jżomm istampar, iżommu l-istampar, iżommu
istampar, iżommu l-istampar, iżommu l-istampar,

993
00:40:59,810 --> 00:41:03,781
it-triq kollha għall-karattru 50,
li min jaf x'inhu jiġri.

994
00:41:03,781 --> 00:41:05,030
Mela ejja fil-fatt tagħti ħarsa.

995
00:41:05,030 --> 00:41:06,720
Ejja tip fil Zamyla.

996
00:41:06,720 --> 00:41:07,250
Interessanti.

997
00:41:07,250 --> 00:41:08,190
Sirna xxurtjati.

998
00:41:08,190 --> 00:41:09,700
Just mazz sħiħ ta 'l-ispazju abjad.

999
00:41:09,700 --> 00:41:09,930
Oh.

1000
00:41:09,930 --> 00:41:11,120
Hemm karattru wieħed funky.

1001
00:41:11,120 --> 00:41:14,577
Huwa jistenna tip simili ta 'kwistjoni stramb
jimmarkaw hemm, iżda hemm isem Zamyla tal.

1002
00:41:14,577 --> 00:41:15,660
Ejja nneħħu verament imprudenti.

1003
00:41:15,660 --> 00:41:20,000
Kif madwar aħna jistampa 500
blokki fil-mhux magħruf?

1004
00:41:20,000 --> 00:41:24,380
Ejja imorru quddiem u jagħmlu dan
kif ukoll u mbagħad run mill-ġdid.

1005
00:41:24,380 --> 00:41:27,980
U ejja full screen dan, għaliex
jeħtieġ li naraw aktar spazju.

1006
00:41:27,980 --> 00:41:30,460
Zamyla.

1007
00:41:30,460 --> 00:41:31,830
Ghandek xxurtjati darb'oħra.

1008
00:41:31,830 --> 00:41:33,070
>> Ippruvaw nikbru aktar imprudenti?

1009
00:41:33,070 --> 00:41:36,070
Ejja nneħħu aktar imprudenti.

1010
00:41:36,070 --> 00:41:39,350
50,000 karattri.

1011
00:41:39,350 --> 00:41:41,390
Dan huwa l-aktar żgur mhijiex idea tajba.

1012
00:41:41,390 --> 00:41:41,890
Kull dritt.

1013
00:41:41,890 --> 00:41:42,990
Jagħmlu string 0.

1014
00:41:42,990 --> 00:41:44,720
Dan se jkun l-aħħar demo tagħna.

1015
00:41:44,720 --> 00:41:47,261
Zamyla.

1016
00:41:47,261 --> 00:41:48,632
Ugh.

1017
00:41:48,632 --> 00:41:50,010
Ugh.

1018
00:41:50,010 --> 00:41:50,680
KOLLOX SEW.

1019
00:41:50,680 --> 00:41:54,407
Allura memorja tiegħi huwa verament vojta dritt issa,
li huwa attwalment tip ta 'konvenjenti.

1020
00:41:54,407 --> 00:41:55,990
Dak li jien tipprova tikseb to-- id-dritt.

1021
00:41:55,990 --> 00:41:57,614
U issa jien biss se tikseb imprudenti.

1022
00:41:57,614 --> 00:41:58,570
500000.

1023
00:41:58,570 --> 00:42:03,860
Make-- ejja full screen dan.

1024
00:42:03,860 --> 00:42:04,990
Ikteb.

1025
00:42:04,990 --> 00:42:05,490
Zamyla.

1026
00:42:05,490 --> 00:42:12,050

1027
00:42:12,050 --> 00:42:13,390
Hemm immorru.

1028
00:42:13,390 --> 00:42:15,610
Għandi l-ebda idea dak li
huwa, iżda ħsejjes ħażin.

1029
00:42:15,610 --> 00:42:16,110
Kull dritt.

1030
00:42:16,110 --> 00:42:20,322
U fil-fatt, hekk, jekk int fost
il-ftit fortunati fl ħinijiet tal-uffiċċju

1031
00:42:20,322 --> 00:42:22,780
u problema sett wieħed, inti
tista 'tajjeb ħafna jiltaqgħu dan.

1032
00:42:22,780 --> 00:42:25,490
Tort Segmentazzjoni attwalment ma
għandhom tifsira definita tajjeb.

1033
00:42:25,490 --> 00:42:28,450
Dan ifisser xi tip ta 'żball
dwar segment ta 'memorja.

1034
00:42:28,450 --> 00:42:30,490
U f'termini laymans,
dan ifisser li aħna mimsus

1035
00:42:30,490 --> 00:42:34,780
memory-- aħna użati RAM fil-kompjuter tiegħi
li jien ma kellhiex aċċess għall.

1036
00:42:34,780 --> 00:42:37,050
U dan huwa dak dawn, kemm
qawwija u wkoll perikolużi

1037
00:42:37,050 --> 00:42:39,910
dwar C hija li inti fil-fatt
jkollhom aċċess bla xkiel

1038
00:42:39,910 --> 00:42:45,910
l-intier tal-memorja programm tiegħek
jew bytes jew RAM, b'mod aktar speċifiku.

1039
00:42:45,910 --> 00:42:49,510
>> Allura anke jekk l-isem Zamyla ta
huwa biss sitt karattri fit-tul,

1040
00:42:49,510 --> 00:42:51,450
I xorta tista 'tmur kullimkien
fil-memorja irrid.

1041
00:42:51,450 --> 00:42:53,491
U bħala twarrib, jekk inti stajt
qatt taqra xi artiklu

1042
00:42:53,491 --> 00:42:55,610
matul is-snin dwar xi
server jew xi program

1043
00:42:55,610 --> 00:42:58,654
jkollna maqsum jew Hacked li l
jittieħed vantaġġ ta 'xi ħaġa

1044
00:42:58,654 --> 00:43:00,820
imsejħa overflow buffer
jisfruttaw li aħna ser fil-fatt

1045
00:43:00,820 --> 00:43:04,970
jitkellmu dwar fi ftit ġimgħat, li
ġeneralment jirreferu għall b'xi mod tricking

1046
00:43:04,970 --> 00:43:09,090
kompjuter fis sejjer tajjeb
lil hinn mill-konfini tal-memorja

1047
00:43:09,090 --> 00:43:11,410
li għandu jkollu, u
konstatazzjoni xi ħaġa mmerraq

1048
00:43:11,410 --> 00:43:13,530
f'dak memory-- a
password, forsi, mod

1049
00:43:13,530 --> 00:43:16,990
evitati xi numru tas-serje
jivverifikaw, jew eżatt ġeneralment kapaċi

1050
00:43:16,990 --> 00:43:20,360
trick il-kompjuter tkun qed teżegwixxi
kodiċi li ma kienx maħsub.

1051
00:43:20,360 --> 00:43:22,360
Imma ejja terga 'lura għal
realtà għal ftit mument

1052
00:43:22,360 --> 00:43:24,550
fejn dan il-programm kien
implimentati strlen,

1053
00:43:24,550 --> 00:43:26,110
u jintroduċu ħaġa waħda up here.

1054
00:43:26,110 --> 00:43:30,030
X'hemm ġdid fost dawn aqwa tliet linji?

1055
00:43:30,030 --> 00:43:30,910
>> Allura string dot h.

1056
00:43:30,910 --> 00:43:35,490
Jirriżulta hemm din il-librerija imsejħa
String Dot H, jew il-Librerija String,

1057
00:43:35,490 --> 00:43:38,490
li fajl header, biex ngħidu hekk,
huwa string dot h li tagħti me

1058
00:43:38,490 --> 00:43:40,860
aċċess għal din il-funzjoni strlen.

1059
00:43:40,860 --> 00:43:43,841
Jekk I jħalli barra dan, il-kompilatur hija
ser Yell fil lili f'xi forma.

1060
00:43:43,841 --> 00:43:44,590
Imma inti taf liema?

1061
00:43:44,590 --> 00:43:46,090
Issa ejja nikseb verament sfumat.

1062
00:43:46,090 --> 00:43:50,820
F'konformità 22, hemm tip xi ħaġa
tal inefficient-- ħażin ddisinjati,

1063
00:43:50,820 --> 00:43:53,990
arguably-- dwar din il-linja tal-kodiċi.

1064
00:43:53,990 --> 00:43:56,280
Think lura għal kif
-għal loop jiġu implimentati

1065
00:43:56,280 --> 00:44:00,140
u x'passi jiġri mill-ġdid u
ġdid u again-- l inizjalizzazzjoni,

1066
00:44:00,140 --> 00:44:04,110
il-kundizzjoni, il-kodiċi li
gets esegwiti, allura l-inkrement

1067
00:44:04,110 --> 00:44:07,880
jew il-bidla, allura l-kundizzjoni,
allura l-kodiċi, il-bidla, allura

1068
00:44:07,880 --> 00:44:11,280
il-kundizzjoni, allura l-kodiċi,
il-bidla, u oħrajn.

1069
00:44:11,280 --> 00:44:15,320
Allura dak li jista 'jkun ftit
tħassib jew ħażin isir hawn?

1070
00:44:15,320 --> 00:44:16,387
Yeah, bil-blu.

1071
00:44:16,387 --> 00:44:18,220
UDJENZA: Strlen hija
imsejħa ħafna, ħafna drabi.

1072
00:44:18,220 --> 00:44:20,654

1073
00:44:20,654 --> 00:44:21,320
SPEAKER 1: Yeah.

1074
00:44:21,320 --> 00:44:23,700
Allura strlen huwa msejjaħ
ħafna drabi, imma dak li hu

1075
00:44:23,700 --> 00:44:27,113
it-tul ta 'isem Zamyla tal-
ewwel darba l-linja tesegwixxi?

1076
00:44:27,113 --> 00:44:27,860
>> UDJENZA: Sitt.

1077
00:44:27,860 --> 00:44:28,110
>> SPEAKER 1: Sitt.

1078
00:44:28,110 --> 00:44:30,976
Ukoll, dak li huwa t-tul ta 'isem tagħha
it-tieni darba l-kodiċi tesegwixxi?

1079
00:44:30,976 --> 00:44:31,432
>> UDJENZA: Sitt.

1080
00:44:31,432 --> 00:44:31,890
>> SPEAKER 1: Id-dritt.

1081
00:44:31,890 --> 00:44:32,720
Huwa għadu sitt.

1082
00:44:32,720 --> 00:44:33,220
Dritt?

1083
00:44:33,220 --> 00:44:35,260
Isem Zarla għadha ma
mibdula, anki jekk I infittex

1084
00:44:35,260 --> 00:44:38,240
fil biss parti mill-ittri fl-isem tagħha.

1085
00:44:38,240 --> 00:44:41,349
U għalhekk l-fatt li jien effettivament
tistaqsi din il-mistoqsija, x'hemm

1086
00:44:41,349 --> 00:44:44,640
it-tul ta 'Zamyla, x'inhu l-tul
tal Zamyla, x'inhu t-tul tal Zamyla,

1087
00:44:44,640 --> 00:44:47,990
sitt darbiet separati, jew
seba anki, huwa biss stupid,

1088
00:44:47,990 --> 00:44:50,390
minħabba li l jinbidlux din ir-risposta.

1089
00:44:50,390 --> 00:44:53,550
U hekk dak I jistgħu attwalment
tagħmel huwa this-- fi string wieħed

1090
00:44:53,550 --> 00:44:55,680
Għandi verżjoni marġinalment aħjar hawnhekk.

1091
00:44:55,680 --> 00:45:00,110
There-- string whoops-- żewġ Għandi
verżjoni marġinalment aħjar wherein

1092
00:45:00,110 --> 00:45:05,010
I do this-- minflok sempliċiment
initializing i għal 0, I wkoll b'virgola

1093
00:45:05,010 --> 00:45:07,990
tiddikjara t-tieni varjabbli imsejjaħ
n-- I ma jkollhom jgħidu int ġdid.

1094
00:45:07,990 --> 00:45:09,220
I m'għandhiex, fil-fatt.

1095
00:45:09,220 --> 00:45:10,380
Imma jien ngħid n.

1096
00:45:10,380 --> 00:45:13,610
U mbagħad I initialize n li
l strlen ta n, hekk li issa

1097
00:45:13,610 --> 00:45:17,110
kif ħafna drabi ma strlen
nikseb esegwiti total?

1098
00:45:17,110 --> 00:45:17,610
Just darba.

1099
00:45:17,610 --> 00:45:20,257
U għalhekk dan huwa dak li rridu nfissru
qabel dwar id-disinn aħjar.

1100
00:45:20,257 --> 00:45:23,090
Attwalment ladarba kodiċi tiegħek hija korretta,
tmur lura u l-ħsieb permezz,

1101
00:45:23,090 --> 00:45:26,820
am I jużaw inqas
memorja jew bħala ftit sekondi

1102
00:45:26,820 --> 00:45:30,409
jew millisekondi ta 'żmien tal-kompjuter bħala
possibbli li jiġu implimentati xi problema?

1103
00:45:30,409 --> 00:45:32,200
U jien ser tiskrollja
up u biss isemmu

1104
00:45:32,200 --> 00:45:34,283
li hemm dan aċċenn
ta null f'dan il-verżjoni,

1105
00:45:34,283 --> 00:45:36,390
iżda aħna ser terga 'lura għal li qabel twil.

1106
00:45:36,390 --> 00:45:41,010
Minħabba għal issa, ejja tagħti ħarsa
lejn fejn din se iwassalna.

1107
00:45:41,010 --> 00:45:44,110
Allura wieħed, jirriżulta li
issa li għandna l-ħila

1108
00:45:44,110 --> 00:45:46,860
li tħares lejn karattri individwali,
nistgħu lieva xi ħaġa

1109
00:45:46,860 --> 00:45:50,807
minn ġimgħa 0 dik kienet arcane ħafna u
tip ta 'uninteresting fil-ħin.

1110
00:45:50,807 --> 00:45:53,390
Imma issa, u speċjalment meta aħna
insir kriptografija fil-ġimgħa,

1111
00:45:53,390 --> 00:45:54,820
li għaddej biex tkun pretty qawwija.

1112
00:45:54,820 --> 00:45:57,450
Jirriżulta li b'xi
ints u sufruni data types--

1113
00:45:57,450 --> 00:46:00,300
u Chars u kordi u
oħra things-- xi wħud minnhom

1114
00:46:00,300 --> 00:46:02,800
jista 'jiġi faċilment konvertit għal ieħor.

1115
00:46:02,800 --> 00:46:05,840
>> Per eżempju, meta tkellimna
dwar ASCII xi żmien ago-- hawnhekk

1116
00:46:05,840 --> 00:46:07,796
l-ittri kapitali A
permezz M, dot, dot,

1117
00:46:07,796 --> 00:46:12,530
dot-- għidna li hemm immappjar
bejn dawn l-ittri u numri.

1118
00:46:12,530 --> 00:46:14,970
U fil-fatt, huwa minnu
għall-ittri lowercase kif ukoll.

1119
00:46:14,970 --> 00:46:17,470
Zghar a huwa 97, il-kapital ta 'huwa ta '65.

1120
00:46:17,470 --> 00:46:20,860
U hemm numru fil ASCII,
li huwa biss dan mapping

1121
00:46:20,860 --> 00:46:23,240
sistema għal kulħadd ta 'dawn l-ittri l-oħra.

1122
00:46:23,240 --> 00:46:25,030
Allura dak li jfisser?

1123
00:46:25,030 --> 00:46:28,390
Well, jien ser jimxi 'l quddiem u miftuħa
up reali malajr xi ħaġa imsejħa

1124
00:46:28,390 --> 00:46:31,240
ASCII 0, li ħafna minnhom huwa kummenti.

1125
00:46:31,240 --> 00:46:33,860
U għal darb'oħra online inti tista 'dejjem
t'għajn permezz tal-kummenti.

1126
00:46:33,860 --> 00:46:36,180
>> U tagħti ħarsa dak
dan se tagħmel.

1127
00:46:36,180 --> 00:46:38,410
Allura huwa ltqajna funzjoni prinċipali.

1128
00:46:38,410 --> 00:46:41,490
Stajt hard-kodifikati in-numri biss għall
issa, għaliex naf dak li qed nagħmel.

1129
00:46:41,490 --> 00:46:42,950
Naf dak li nixtieq li tara hawn.

1130
00:46:42,950 --> 00:46:45,220
U stajt initialized I sa 65.

1131
00:46:45,220 --> 00:46:48,490
U jien għadd up
permezz 26 ittri totali.

1132
00:46:48,490 --> 00:46:52,990
U dak li jien ser
print linja waħda fi żmien

1133
00:46:52,990 --> 00:46:54,930
jekk inti tista 'tinterpreta
din il-linja enfasizzat?

1134
00:46:54,930 --> 00:46:55,970
Liema gets stampati?

1135
00:46:55,970 --> 00:46:56,797
Yeah.

1136
00:46:56,797 --> 00:46:57,264
>> UDJENZA: Inti ser
li jistampaw l-ittra li

1137
00:46:57,264 --> 00:46:59,805
tikkorrispondi għall-mappa tal-
valur ittra u l-valur sħiħ?

1138
00:46:59,805 --> 00:47:01,199

1139
00:47:01,199 --> 00:47:01,990
SPEAKER 1: Eżattament.

1140
00:47:01,990 --> 00:47:04,740
Jien ser jistampaw l-ittra
jikkorrispondi għall-valur sħiħ,

1141
00:47:04,740 --> 00:47:06,131
u viċi versa, kif ġej.

1142
00:47:06,131 --> 00:47:08,880
Ukoll dan, xi ħadd qal qabel,
huwa biss placeholder għal char.

1143
00:47:08,880 --> 00:47:09,490
Xorta waħda huwa.

1144
00:47:09,490 --> 00:47:12,280
Dan, naturalment, huwa placeholder
għal int-- ma 'linja ġdida.

1145
00:47:12,280 --> 00:47:18,140
U issa avviż, l-ewwel valur tiegħi li
Jien fejn jitwaħħal fl għal dak placeholder

1146
00:47:18,140 --> 00:47:22,320
huwa mhux biss I. jien qal,
fil-parentesi, char I,

1147
00:47:22,320 --> 00:47:26,700
li l char parenthetical hija
javżak il kompilatur, jittrattaw I

1148
00:47:26,700 --> 00:47:28,490
mhux bħala dak li hi, li huwa għadd.

1149
00:47:28,490 --> 00:47:30,490
Titratta dan bħala karattru attwali.

1150
00:47:30,490 --> 00:47:34,490
Billi t-tieni valur jien fejn jitwaħħal
in-- I-- għandu jkun biss numru.

1151
00:47:34,490 --> 00:47:38,140
>> Mela jekk jien jiġbor dan program--
għalhekk dan huwa jagħmel ASCII 0,

1152
00:47:38,140 --> 00:47:41,720
ASCII dot slash 0-- I biss jiksbu
din it-tabella ftit handy li

1153
00:47:41,720 --> 00:47:44,950
turi me kollha tal-possibbli
mappings mingħajr ma jkollhom biex jaħsbu li

1154
00:47:44,950 --> 00:47:46,450
permezz ta 'jew figura hija out fuq tiegħi stess.

1155
00:47:46,450 --> 00:47:48,783
U jien ukoll stampar out,
avviż l-ittri zghar,

1156
00:47:48,783 --> 00:47:51,410
minħabba ftit linji aktar tard, I
wkoll jistampa din mapping

1157
00:47:51,410 --> 00:47:53,737
kif ukoll, li huwa biss biex
jgħidu li ladarba inti tifhem

1158
00:47:53,737 --> 00:47:55,570
x'inhu għaddej taħt
il-barnuża, tista 'inti

1159
00:47:55,570 --> 00:47:57,111
awtomatikament tikkonverti quddiem u lura.

1160
00:47:57,111 --> 00:48:00,160
U fil-fatt, jekk kwalunkwe inti
qatt ma dan fl-iskola grad

1161
00:48:00,160 --> 00:48:03,490
jew smajt dwar xi ħadd
mythically tieħu nota

1162
00:48:03,490 --> 00:48:05,620
u jgħaddiha lill tiegħu
jew ħabib tagħha fil-klassi,

1163
00:48:05,620 --> 00:48:08,300
imma int scrambled l-
ittri mill like A issir B,

1164
00:48:08,300 --> 00:48:11,240
u B isir C, jew xi ħaġa
aktar ikkumplikat minn dan, ukoll,

1165
00:48:11,240 --> 00:48:13,410
kif tista 'tmur dwar
implimentazzjoni li bħala kid?

1166
00:48:13,410 --> 00:48:16,340
Well, inti biss tip ta 'know
A isir B, B isir C,

1167
00:48:16,340 --> 00:48:19,700
iżda matematikament,
dak li kien li kid tagħmel?

1168
00:48:19,700 --> 00:48:22,050
X'kont qed żżid ma 'kull ittra?

1169
00:48:22,050 --> 00:48:23,340
Effettivament, 1.

1170
00:48:23,340 --> 00:48:27,740
>> Allura meta inti tbiddel A sa B, li
tip ta 'bħal tibdil 65-66,

1171
00:48:27,740 --> 00:48:29,590
li matematikament jfisser biss żid 1.

1172
00:48:29,590 --> 00:48:33,300
U hekk jekk ġejt biex jimplimentaw
teknika qarrieqa li ftit

1173
00:48:33,300 --> 00:48:36,380
għall-għalliema tiegħek fil-kodiċi, inti
tista 'tagħmel eżattament dan biss

1174
00:48:36,380 --> 00:48:38,552
billi żżid ittra waħda flimkien.

1175
00:48:38,552 --> 00:48:40,260
Allura qabel twil, aħna qed
ser tara kif aħna

1176
00:48:40,260 --> 00:48:43,300
jistgħu jieħdu vantaġġ minn dik li attwalment
ġirja ġenwinament u Unscramble

1177
00:48:43,300 --> 00:48:43,991
informazzjoni.

1178
00:48:43,991 --> 00:48:47,240
Fil-frattemp, jafu li konna beda
li tintroduċi koppja libreriji oħra

1179
00:48:47,240 --> 00:48:48,990
here---sekwenza waħda llum.

1180
00:48:48,990 --> 00:48:51,180
U sit utli ħafna
nisperaw li int ser issib

1181
00:48:51,180 --> 00:48:55,010
huwa msejjaħ reference.cs50.net, li
l-għalliema ġabru,

1182
00:48:55,010 --> 00:48:57,510
b'tali mod li jekk inti tixtieq li
wieħed ifittex xogħol kif strlen,

1183
00:48:57,510 --> 00:48:59,300
inti tista 'tibda ittajpjar
isem il-funzjoni tal-

1184
00:48:59,300 --> 00:49:02,890
ikklikkja strlen hemm, u mbagħad
spjegazzjoni inqas komdi

1185
00:49:02,890 --> 00:49:03,700
se jidhru.

1186
00:49:03,700 --> 00:49:06,880
Jew jekk inti tixtieq l-uffiċjal
Spjegazzjoni Linux bbażati,

1187
00:49:06,880 --> 00:49:08,945
tista 'tagħfas aktar comfy
fil kantuniera, u dan

1188
00:49:08,945 --> 00:49:12,070
se tippreżenta l-istess informazzjoni,
imma f'termini iktar kumplessi.

1189
00:49:12,070 --> 00:49:15,070
Li riżors utli li
tassew taf liema kollox ma.

1190
00:49:15,070 --> 00:49:17,320
>> Next time aħna qed tmur biex
tagħti ħarsa lejn Ovaltine

1191
00:49:17,320 --> 00:49:20,070
u aktar, u jintroduċu nfusna
għad-dinja tal-kriptografija.

1192
00:49:20,070 --> 00:49:21,930
Qabel dakinhar, aħna ser tara
inti aktar tard din il-ġimgħa.

1193
00:49:21,930 --> 00:49:23,390
U issa, Colton Ogden.

1194
00:49:23,390 --> 00:49:26,730
Ara inti fuq l-Erbgħa.

1195
00:49:26,730 --> 00:49:30,216
>> [Daqq tal-mużika]

1196
00:49:30,216 --> 00:49:33,702
>> [Daqq tal-mużika]

1197
00:49:33,702 --> 00:49:38,682

1198
00:49:38,682 --> 00:49:42,200
>> SPEAKER 1: X'inhu l-
[Bleep] inti tagħmel?

1199
00:49:42,200 --> 00:49:45,720
>> SPEAKER 1: I am tiekol deżerta tiegħi?

1200
00:49:45,720 --> 00:49:47,160
Kif inti jieklu?

1201
00:49:47,160 --> 00:49:47,860
B'idejk?

1202
00:49:47,860 --> 00:49:54,050

1203
00:49:54,050 --> 00:49:57,940
>> [Daqq tal-mużika]

1204
00:49:57,940 --> 00:50:03,453