1 00:00:00,000 --> 00:00:01,500 >> [Daqq ta mużika] 2 00:00:01,500 --> 00:00:11,000 3 00:00:11,000 --> 00:00:16,110 >> DAVID Malan: Kull dritt dan huwa CS50 u dan huwa t-tmiem ta 'ġimgħa. 4 00:00:16,110 --> 00:00:20,760 So I tixtieq tintroduċi eks tiegħi advisee, Andel Duff, li mhux biss jagħmel 5 00:00:20,760 --> 00:00:25,460 iPhone 5 stands, kif ukoll dan lectern, huwa jagħmel ukoll karozzi. 6 00:00:25,460 --> 00:00:27,927 7 00:00:27,927 --> 00:00:29,510 ANSEL DUFF: Kif jgħid huwa għaddej, kulħadd? 8 00:00:29,510 --> 00:00:31,980 I biss trid jgħidlek ftit ftit dwar Formula SAE, li jien 9 00:00:31,980 --> 00:00:32,604 am-kaptan. 10 00:00:32,604 --> 00:00:33,437 Huwa ta 'tim MIT. 11 00:00:33,437 --> 00:00:35,520 I biss trid jgħidlek guys ftit dwar dan 12 00:00:35,520 --> 00:00:37,520 u nisperaw jiġġeneraw xi interess. 13 00:00:37,520 --> 00:00:41,590 >> So let me biss run permezz ta ' koppja affarijiet dwar it-tim tagħna. 14 00:00:41,590 --> 00:00:43,640 Allura aħna qed kompletament student run, wherein kollha 15 00:00:43,640 --> 00:00:47,300 tad-disinn membri, jissimulaw, test, u l-manifattur sottosistema 16 00:00:47,300 --> 00:00:48,090 tal-karozza. 17 00:00:48,090 --> 00:00:51,240 Għandna ħanut magna tagħna stess u garaxxijiet, u N52-- jew sorry, 18 00:00:51,240 --> 00:00:54,140 N51-- li hija l-istess bini bħala l-MIT Xjenza Museum. 19 00:00:54,140 --> 00:00:55,990 U aħna huma l-persuni li jsuq il-karozza. 20 00:00:55,990 --> 00:00:58,340 Hemm kompetizzjoni nazzjonali fil-bidu tas-sajf, 21 00:00:58,340 --> 00:01:01,215 u allura hemm penalties iżgħar kompetizzjonijiet matul is-sena. 22 00:01:01,215 --> 00:01:04,400 U allura aħna nagħmlu taħriġ ta 'sewwieq ġranet biex tikseb membri ġodda familjari. 23 00:01:04,400 --> 00:01:08,280 >> Jiem jibnu tagħna huma fuq Sibtijiet 11:00-20:00. 24 00:01:08,280 --> 00:01:11,060 Lunch u dinner qed tieħu ħsieb ta ', minn dik tas-Bertucci u Beantown 25 00:01:11,060 --> 00:01:12,130 rispettivament. 26 00:01:12,130 --> 00:01:15,260 Għandna laqgħa ta 'kull ġimgħa u seminar, li huwa għall-kreditu kors. 27 00:01:15,260 --> 00:01:18,560 Li huwa ġdid bħala ta 'dan is-semestru, u se jkun ukoll għall semestru li jmiss, 28 00:01:18,560 --> 00:01:19,940 sabiex inti tista 'jaqsmu reg għal dak. 29 00:01:19,940 --> 00:01:22,960 U allura għandna tfassil, shop, u l-ġranet CAD matul il-ġimgħa, 30 00:01:22,960 --> 00:01:26,870 billi l-membri se indipendentement Partijiet CAD, stokk ordni eċċetera. 31 00:01:26,870 --> 00:01:29,200 >> Allura għal elettriku inġinerija fil-tim 32 00:01:29,200 --> 00:01:31,110 għandna trattiva tagħna, sistema ta 'vultaġġ għoli, 33 00:01:31,110 --> 00:01:33,390 li tmur fi nominali 300 volt, li tinkludi 34 00:01:33,390 --> 00:01:35,360 muturi, kontrolluri tal-muturi, u pakki ta 'batteriji. 35 00:01:35,360 --> 00:01:37,235 Imbagħad għandna baxxa sistema vultaġġ, li tmur 36 00:01:37,235 --> 00:01:40,180 fit-12-volt, li jinkludi kontrolli, CAN lymph, il-moħħ 37 00:01:40,180 --> 00:01:41,570 kaxxa, u l-dashboard. 38 00:01:41,570 --> 00:01:43,890 Safejn CS tmur, nagħmlu jkollhom manutenzjoni website 39 00:01:43,890 --> 00:01:47,940 li għandna bżonn isir għal avvenimenti, sħubija bidliet, stampi ġodda, u materjal PR. 40 00:01:47,940 --> 00:01:51,540 U allura għandna kodiċi li jikkontrolla l- karozza għal kontroll ta 'trazzjoni tagħna, tnedija 41 00:01:51,540 --> 00:01:55,750 kontroll, kontroll sing, vettoru torque, u sistemi ta 'brejkijiet riġenerattiva, li 42 00:01:55,750 --> 00:01:59,170 run tipikament fil MATLAB, Simulink, u Labview. 43 00:01:59,170 --> 00:02:00,910 >> Jgħidlek ftit dwar il-karozza. 44 00:02:00,910 --> 00:02:02,470 Allura huwa madwar 500 liri. 45 00:02:02,470 --> 00:02:04,285 Huwa regoli limitati għal 85 f'kilowatts. 46 00:02:04,285 --> 00:02:08,310 Hija 2 EMRAX 207 muturi fil- lura, wieħed għal kull rota ta 'wara. 47 00:02:08,310 --> 00:02:11,880 Hija pakketti mibnija apposta batterija minn ċelluli A123 pouch priżmatiċi, 48 00:02:11,880 --> 00:02:14,780 jammontaw 300 volt u 5.6 sigħat kilowatt. 49 00:02:14,780 --> 00:02:17,950 U huwa drive diretta ma ' proporzjon 2.64-1 drive. 50 00:02:17,950 --> 00:02:20,970 Hawn huma xi ritratti aħna ħa ta 'dan fil-kompetizzjoni. 51 00:02:20,970 --> 00:02:25,820 Hawn il-kon-dahar, imnieħer, u hawn huma l-muturi, 52 00:02:25,820 --> 00:02:29,682 dawk disks big black taħt l-et mens manus. 53 00:02:29,682 --> 00:02:32,140 Hawn slide li I jinġibed out ta 'l-iskema kompetizzjoni tagħna. 54 00:02:32,140 --> 00:02:35,389 U dan huwa biss jqabbel karozza tagħna għal Koppja ta 'karozzi disponibbli kummerċjalment, 55 00:02:35,389 --> 00:02:38,380 bħall-XBOW KTM, Ariel Atom, u Caterha M 7-280. 56 00:02:38,380 --> 00:02:42,110 Jekk int familjari mal-prezz, l-enerġija iġbed piż, dollaru kull horsepower, 57 00:02:42,110 --> 00:02:44,930 dollaru kull torque, u karozza tagħna daqqa lilhom kollha barra mill-ilma. 58 00:02:44,930 --> 00:02:47,520 Jekk għandek xi mistoqsijiet, LOGHOME stabbiliti dan l-indirizz email. 59 00:02:47,520 --> 00:02:50,800 Rimja email fuq fsae@mit.edu. 60 00:02:50,800 --> 00:02:53,350 >> Aħna kuntenti li jitkellmu dwar xi ħaġa li tixtieq. 61 00:02:53,350 --> 00:02:55,600 Istudenti Harvard huma tip tal-minoranza fuq it-tim. 62 00:02:55,600 --> 00:02:58,350 Jekk għandek xi mistoqsijiet dwar li jekk jogħġbok do rimja us email, 63 00:02:58,350 --> 00:03:00,810 kuntenti li jitkellmu, u jien ser ras lura fuq għall David. 64 00:03:00,810 --> 00:03:01,550 Grazzi. 65 00:03:01,550 --> 00:03:02,466 I japprezzaw dan, guys. 66 00:03:02,466 --> 00:03:03,615 [Applause] 67 00:03:03,615 --> 00:03:07,080 68 00:03:07,080 --> 00:03:10,980 >> DAVID Malan: Ansel jintefqu-sajf taħdem magħna hawn fuq il-kampus fil CS50 69 00:03:10,980 --> 00:03:11,480 dan is-sajf. 70 00:03:11,480 --> 00:03:13,505 U minbarra li jaħdmu fuq affarijiet bħall-basal binarja, 71 00:03:13,505 --> 00:03:16,090 hu attwalment verament fetaħ tagħna eyes-- u mini fid particular-- 72 00:03:16,090 --> 00:03:20,535 għal dak li verament l-intersezzjoni ta ' mhux ta 'hardware u software jista' jkun. 73 00:03:20,535 --> 00:03:23,410 Fil-fatt ħafna mill-affarijiet hu biss daret inti permezz huma finalment 74 00:03:23,410 --> 00:03:26,030 maħluqa ewwel fis-software, u mbagħad finalment iffabbrikat 75 00:03:26,030 --> 00:03:27,299 fid-dinja reali fil-hardware. 76 00:03:27,299 --> 00:03:29,590 Mela jekk int interessat fil- esplorazzjoni li intersezzjoni, 77 00:03:29,590 --> 00:03:31,430 forsi tieħu up dak il-grupp. 78 00:03:31,430 --> 00:03:34,140 >> Issa sadanittant, dawk minnkom li huma fannijiet ta 'teknoloġija, 79 00:03:34,140 --> 00:03:36,140 u prodotti tat-tuffieħ fil partikolari jafu li hemm 80 00:03:36,140 --> 00:03:37,860 kienu koppja ta ' Avviżi bieraħ. 81 00:03:37,860 --> 00:03:39,776 Iżda ħsibna aħna'd juru inti wieħed li ħareġ 82 00:03:39,776 --> 00:03:43,590 ftit jiem qabel dik inti tista 'ma raw. 83 00:03:43,590 --> 00:03:46,150 >> Jorgen EGHAMMER: You know, darba fil xi ħaġa awhile 84 00:03:46,150 --> 00:03:49,540 ġejja flimkien li Tibdel il-mod kif ngħixu. 85 00:03:49,540 --> 00:03:53,479 Mezz tant sempliċi u intuwittivi użu iħoss kważi familjari. 86 00:03:53,479 --> 00:03:59,710 87 00:03:59,710 --> 00:04:04,138 L-introduzzjoni 2015 katalogu IKEA. 88 00:04:04,138 --> 00:04:10,420 Mhuwiex ktieb diġitali jew e-book, huwa ktieb ktieb. 89 00:04:10,420 --> 00:04:14,440 >> L-ewwel ħaġa li wieħed jinnota l-ebda kejbils, lanqas power cable. 90 00:04:14,440 --> 00:04:18,519 Il-katalgu IKEA 2015 taqa ċċarġjati kompletament, 91 00:04:18,519 --> 00:04:20,550 u l-ħajja tal-batteriji hija dejjiema. 92 00:04:20,550 --> 00:04:27,300 L-interface huwa 7.5 bi 8 pulzier, iżda jistgħu jespandu sa 15 minn 8 pulzier. 93 00:04:27,300 --> 00:04:32,410 Il-navigazzjoni hija bbażata fuq touch tactile teknoloġija li inti tista 'attwalment iħossu. 94 00:04:32,410 --> 00:04:37,120 >> Kontenut jiġi installat minn qabel via 328 paġni ta 'definizzjoni għolja 95 00:04:37,120 --> 00:04:40,180 jispira ideat dar dar. 96 00:04:40,180 --> 00:04:43,740 Biex tibda browsing, sempliċiment touch u drag. 97 00:04:43,740 --> 00:04:50,870 Lemin għax-xellug biex jimxu 'l quddiem, xellug għal-lemin biex jimxu lura. 98 00:04:50,870 --> 00:04:52,770 >> Avviż xi ħaġa oħra? 99 00:04:52,770 --> 00:04:53,780 Dak id-dritt. 100 00:04:53,780 --> 00:04:55,190 Nru lag. 101 00:04:55,190 --> 00:04:58,400 Kull paġna ċara kristall tagħbijiet istantanju, 102 00:04:58,400 --> 00:05:00,586 ebda kwistjoni kif fast inti iscroll. 103 00:05:00,586 --> 00:05:03,710 Jekk inti tixtieq li tikseb ħarsa ta 'malajr, biss żommha fil-keffa ta 'idejk, 104 00:05:03,710 --> 00:05:06,816 u bl-użu biss thumb tiegħek, veloċità jibbrawżjaw il-kontenut. 105 00:05:06,816 --> 00:05:10,930 >> Jekk issib xi ħaġa li inti tixtieq li jiffrankaw għal aktar tard, inti tista 'sempliċement bookmark. 106 00:05:10,930 --> 00:05:17,620 U anki jekk inti qrib l-applikazzjoni, inti tista 'faċilment isibu l-bookmark ġdid. 107 00:05:17,620 --> 00:05:18,490 Amazing. 108 00:05:18,490 --> 00:05:20,434 >> [Rires] 109 00:05:20,434 --> 00:05:21,406 [Applause] 110 00:05:21,406 --> 00:05:26,760 111 00:05:26,760 --> 00:05:29,870 Allura li twassalna biex l-aħħar ta 'ġimgħa. 112 00:05:29,870 --> 00:05:31,760 A ftit avviżi issa. 113 00:05:31,760 --> 00:05:33,440 Allura sezzjonali issa hija fil-progress. 114 00:05:33,440 --> 00:05:36,860 Mur dan il-URL hawn f'xi bejn issa u l-Ġimgħa f'nofsinhar 115 00:05:36,860 --> 00:05:39,960 li attwalment tispeċifika jekk inti fost dawk inqas komdi, aktar 116 00:05:39,960 --> 00:05:41,690 komdu, jew x'imkien bejniethom. 117 00:05:41,690 --> 00:05:44,511 >> Dan huwa tipikament waħda minn dawk affarijiet li inti biss tip ta 'jafu. 118 00:05:44,511 --> 00:05:47,510 U fil-fatt dawk minnkom li huma inqas komdu probabilment taf kemm, 119 00:05:47,510 --> 00:05:49,634 dawk minnkom li huma aktar komdu tkun taf kemm, 120 00:05:49,634 --> 00:05:54,960 u għal darb'oħra jekk m'intix pjuttost ċert liema ta 'dawk bramel inti jaqgħu int 121 00:05:54,960 --> 00:05:56,210 probabbilment x'imkien bejniethom. 122 00:05:56,210 --> 00:05:59,810 Imma mistrieħ assigurat inti tista tpartit wara ftit ġimgħat jekk ikun hemm bżonn. 123 00:05:59,810 --> 00:06:02,620 >> Sadanittant, għall-ġimgħa li ġejjin aħna ma tibda sezzjonijiet per se, 124 00:06:02,620 --> 00:06:04,760 iżda sezzjonijiet super, li huma miftuħa għall-istudenti kollha. 125 00:06:04,760 --> 00:06:08,220 Dan ġejjin Ħadd fil f'post li tkun imħabbra fuq il-websajt kors 126 00:06:08,220 --> 00:06:10,190 aħna se jkollhom waħda għall- dawk inqas komdi, 127 00:06:10,190 --> 00:06:12,470 kif ukoll wieħed għall dawk aktar komda. 128 00:06:12,470 --> 00:06:15,460 U dawk x'imkien bejniethom jistgħu jagħżlu liema minn dawn iż-żewġ, 129 00:06:15,460 --> 00:06:17,360 jew it-tnejn jekk inti tixtieq, biex ipoġġu fil dwar. 130 00:06:17,360 --> 00:06:19,630 U l-fokus ta 'dawk se jkun finalment fuq C, 131 00:06:19,630 --> 00:06:22,440 li aħna ser tkompli tagħna konverżazzjoni tal-lum. 132 00:06:22,440 --> 00:06:25,070 >> Problema sett 0 sadanittant huwa nisperaw fl idejk. 133 00:06:25,070 --> 00:06:27,500 Uffiċjalment għada dovut, Ħamis, f'nofsinhar. 134 00:06:27,500 --> 00:06:29,490 Sakemm inti flus kontanti fl waħda ta '5 ijiem tard tiegħek, 135 00:06:29,490 --> 00:06:31,780 liema bdil iġib dan sakemm il-ġimgħa f'nofsinhar. 136 00:06:31,780 --> 00:06:34,420 Problema stabbilixxa l-1 sadanittant se jkun stazzjonati fuq il-websajt il-kors tal-. 137 00:06:34,420 --> 00:06:37,381 U dan se jkun l-ewwel tagħna foray bħala klassi fis C. 138 00:06:37,381 --> 00:06:40,630 U dik il-problema jistabbilixxu spec se jimxu miegħek permezz ta 'lott ta' l-mechanics ta 'dak li 139 00:06:40,630 --> 00:06:43,960 bdejna nitkellmu nhar it-Tnejn, u aħna ser tkompli jitkellem dwar llum. 140 00:06:43,960 --> 00:06:46,770 C, Linux, il-CS50 appliance, li kollha li 141 00:06:46,770 --> 00:06:48,990 se jistennewkom fil-ispeċifikazzjoni. 142 00:06:48,990 --> 00:06:52,840 >> Uffiċċju siegħa sadanittant huma fil-progress, fis-sala dining undergraduate. 143 00:06:52,840 --> 00:06:56,240 Head sa dan il-URL hawn biex tara d- iskeda għall tonight u għada, 144 00:06:56,240 --> 00:06:57,930 jekk inti tixtieq biex ikollhom sehem. 145 00:06:57,930 --> 00:07:01,920 Mistoqsijiet sadanittant, sabiex inti ikollhom opportunitajiet li jistaqsu mistoqsijiet 146 00:07:01,920 --> 00:07:05,860 asynchronously, 24/7, tirrealizza int mhux limitat għal taqsimiet u l-uffiċċju 147 00:07:05,860 --> 00:07:09,530 sigħat, iżda pjuttost din l-għodda hawn, CS50 Iddiskuti f'dak URL 148 00:07:09,530 --> 00:07:12,150 se tkun online l-kors tal- bulletin board software, li permezz tagħhom 149 00:07:12,150 --> 00:07:15,030 inti tista 'tistaqsi mistoqsijiet ta' klassi u wkoll lill-persunal. 150 00:07:15,030 --> 00:07:18,492 Allura wieħed iżomm f'moħħu li riżorsi kif ukoll. 151 00:07:18,492 --> 00:07:20,200 Sadanittant tradizzjoni jibda dan Ġimgħa. 152 00:07:20,200 --> 00:07:23,200 Kif jista 'jkollok glimpsed minn teaser video nhar l-Erbgħa, 153 00:07:23,200 --> 00:07:25,510 għandna tradizzjoni aktar kull Ġimgħa matul il-mandat 154 00:07:25,510 --> 00:07:28,750 ta 'teħid madwar 50 studenti u persunal lil restorant lokali msejħa 155 00:07:28,750 --> 00:07:31,510 Nar u Silġ, li biha aħna qed tipikament ssieħbu minn xi alumni 156 00:07:31,510 --> 00:07:33,850 jew ħbieb mill-industrija li ġeneralment jaspiraw 157 00:07:33,850 --> 00:07:35,780 biex jagħmlu klassi kbir jħossu iżgħar. 158 00:07:35,780 --> 00:07:37,560 Allura huwa ikla kompletament każwali. 159 00:07:37,560 --> 00:07:40,160 A mazz minna, il-persunal speċjalment, se tilgħab siġġijiet mużikali 160 00:07:40,160 --> 00:07:43,360 u chat ma 'studenti dwar 50, il-ħajja barra ta '50, 161 00:07:43,360 --> 00:07:46,510 ħajja fil-futur, id-dinja reali, Jien jitkellem dwar opportunitajiet ta 'xogħol 162 00:07:46,510 --> 00:07:47,680 mal-ħbieb fl-industrija. 163 00:07:47,680 --> 00:07:51,110 >> Mela jekk inti tixtieq li jingħaqdu magħna dan Ġimgħa, ras għal dan il-URL hawn. 164 00:07:51,110 --> 00:07:54,180 Ispazju huwa limitat, iżda aħna ser nagħmlu dan recurringly tul it-terminu. 165 00:07:54,180 --> 00:07:57,380 Kap hemm biex cs50.harvard.edu/rsvp. 166 00:07:57,380 --> 00:07:59,380 U jekk inti ma tieħux fl dan iż-żmien, biex ma tinkwetax. 167 00:07:59,380 --> 00:08:02,390 Aħna se tagħmel mill-ġdid fil- -ġimgħat li ġejjin kif ukoll. 168 00:08:02,390 --> 00:08:05,434 >> Allura dan huwa l-istampa aħna miżbugħa aħħar ġimgħa, 169 00:08:05,434 --> 00:08:07,350 u inti probabilment ħadthom ġiet dabbling fil s'issa. 170 00:08:07,350 --> 00:08:10,360 Imma ejja jippruvaw li jgħaqqdu dan issa għal dak li aħna qed tmur biex tagħmel illum 171 00:08:10,360 --> 00:08:11,440 u 'l quddiem. 172 00:08:11,440 --> 00:08:14,760 Jista I jkollhom voluntier wieħed? 173 00:08:14,760 --> 00:08:16,000 Kull dritt, jew diversi. 174 00:08:16,000 --> 00:08:18,460 Kif dwar hawn fuq il- aħħar, fil-qmis blu. 175 00:08:18,460 --> 00:08:20,329 Come fuq up, x'hemm isem tiegħek? 176 00:08:20,329 --> 00:08:20,870 Alana: Alana. 177 00:08:20,870 --> 00:08:21,661 DAVID Malan: Alana. 178 00:08:21,661 --> 00:08:25,100 Allura Alana, għal ftit moment-- sbieħ li jissodisfaw you-- 179 00:08:25,100 --> 00:08:28,260 huwa se jkollu l-irwol ta 'din il-funzjoni hawn. 180 00:08:28,260 --> 00:08:31,290 Il-blokk vjola konna imsejħa s'issa funzjoni. 181 00:08:31,290 --> 00:08:34,830 Allura dak li jien se jmorru quddiem hawn u joffru Alana 182 00:08:34,830 --> 00:08:38,380 huwa isem tag ftit, biex jagħmlu ċara liema rwol int playing. 183 00:08:38,380 --> 00:08:39,753 >> Allura inti għandu jkun il-blokk jgħidu. 184 00:08:39,753 --> 00:08:41,419 Jekk inti tixtieq li tmur quddiem u mqiegħda dik fuq. 185 00:08:41,419 --> 00:08:43,169 U aħna qed tmur biex iżommu din super sempliċi. 186 00:08:43,169 --> 00:08:46,180 Jekk l-għan fil-idejn huwa sempliċiment issa biex jimplimentaw Alana, 187 00:08:46,180 --> 00:08:49,710 din l-hekk imsejħa jgħidu blokk, hawnhekk kif li għaddej biex jaħdmu. 188 00:08:49,710 --> 00:08:52,574 I have-- ejja sejħa hija argument jew parametru, 189 00:08:52,574 --> 00:08:54,240 huwa verament ftit folja vojta tal-karta. 190 00:08:54,240 --> 00:08:57,239 U huwa abjad li tip ta 'jkun reminixxenti tal-kaxxa bajda li fih inti 191 00:08:57,239 --> 00:08:58,080 jistgħu jiktbu kliem. 192 00:08:58,080 --> 00:09:00,660 >> Sadanittant jien se jmorru hawn. 193 00:09:00,660 --> 00:09:06,560 Jien ser jimxi 'l quddiem u jiktbu H-E--O L L comma dinja. 194 00:09:06,560 --> 00:09:09,972 U issa I, bħala jiġifieri l-programmer, ma tassew taf kif jgħidu xi ħaġa. 195 00:09:09,972 --> 00:09:12,180 I jistgħu joħorġu bil-kliem, imma jien ma neċessarjament 196 00:09:12,180 --> 00:09:15,220 taf kif jesprimu myself verbalment jew fuq l-iskrin. 197 00:09:15,220 --> 00:09:17,280 U hekk dak li jien ser biex tagħmel huwa li tieħu din il-biċċa 198 00:09:17,280 --> 00:09:21,157 ta 'funzjonalità, li input-- jew argument, kif aħna ser sejħa hija, 199 00:09:21,157 --> 00:09:23,990 Stajt bil-miktub dwar din il-biċċa ta 'paper-- u jien ser jesternalizzaw dan. 200 00:09:23,990 --> 00:09:26,831 >> U fil-fatt li l-irwol li funzjonijiet lingwa ta 'programmar 201 00:09:26,831 --> 00:09:27,330 tista 'tilgħab. 202 00:09:27,330 --> 00:09:29,246 Xi ħaġa bħall-kelma blokk jistgħu jiġu esternalizzati 203 00:09:29,246 --> 00:09:32,074 lil xi ħadd li verament jaf liema hu jew hi qed jitkellem dwar. 204 00:09:32,074 --> 00:09:33,990 Mela jekk inti ser pass fuq hawn għal ftit mument, 205 00:09:33,990 --> 00:09:40,092 I am ser tgħaddi dan input li Alana, u nitolbu li inti ngħid dan input. 206 00:09:40,092 --> 00:09:41,202 >> Alana: Hello, dinja. 207 00:09:41,202 --> 00:09:42,160 DAVID Malan: Dak it. 208 00:09:42,160 --> 00:09:43,326 Allura li hemm funzjoni. 209 00:09:43,326 --> 00:09:46,556 Issa nistgħu teħodha ftit aktar, nistgħu nieħdu pass 'il quddiem hawn. 210 00:09:46,556 --> 00:09:48,180 Minħabba li kien ċar underwhelming. 211 00:09:48,180 --> 00:09:51,670 Mela ejja issa jikkonvertu dan xi ftit aktar sofistikati. 212 00:09:51,670 --> 00:09:53,630 >> Allura dan il-kors huwa verżjoni C tagħna. 213 00:09:53,630 --> 00:09:56,760 Mela issa jekk inti tixtieq li jieħdu dik off wieħed, dak l-isem tag off, 214 00:09:56,760 --> 00:09:58,530 u ejja jkollhom inti tpoġġi fuq isem ġdid. 215 00:09:58,530 --> 00:10:00,850 Imma fundamentalment int jilagħbu l-istess rwol, 216 00:10:00,850 --> 00:10:03,400 huwa biss hekk jiġri li jiġu msejħa printf issa. 217 00:10:03,400 --> 00:10:06,930 >> L-istorja huwa, ovvjament, ser be-- probabbilment 218 00:10:06,930 --> 00:10:09,317 daqstant underwhelming-- huwa ser ikunu dawn li ġejjin. 219 00:10:09,317 --> 00:10:10,650 Inti issa huma l-printf funzjoni. 220 00:10:10,650 --> 00:10:13,300 I am l-sejjieħ, jew il- programmer, li trid 221 00:10:13,300 --> 00:10:15,745 toqgħod fuq l-ispallejn ta ' nies fil-passat bħalek, 222 00:10:15,745 --> 00:10:18,670 li stajt diġà dehret kif li attwalment jikteb xi ħaġa isfel. 223 00:10:18,670 --> 00:10:20,650 U hekk dan iż-żmien, pjuttost milli jgħidu li ejja 224 00:10:20,650 --> 00:10:22,255 attwalment jużaw screen tagħna matul hawn. 225 00:10:22,255 --> 00:10:24,130 Mela jekk inti tixtieq li pass minn hawn, jien ser 226 00:10:24,130 --> 00:10:27,196 li jgħaddu mill-ġdid dan bħala input lill ħabib printf tiegħi. 227 00:10:27,196 --> 00:10:29,320 Jekk inti tista 'tmur quddiem u jistampaw li fuq l-iskrin, 228 00:10:29,320 --> 00:10:31,611 sempliċiment billi tpinġija bil tiegħek swaba fuq l-iskrin iswed. 229 00:10:31,611 --> 00:10:43,680 230 00:10:43,680 --> 00:10:44,180 Eċċellenti. 231 00:10:44,180 --> 00:10:47,350 Kull dritt, lottijiet ta 'suspense għall-bqija kif dak kien se play out. 232 00:10:47,350 --> 00:10:51,390 >> Allura issa ejja jieħdu l-affarijiet up wieħed talja finali, jekk nistgħu, kif ġej. 233 00:10:51,390 --> 00:10:53,980 Allura dan huwa programm C kif aħna qal aħħar darba. 234 00:10:53,980 --> 00:10:57,460 U dan biss ma dak li għamilt, dan prints out għall-iskrin, hello, dinja. 235 00:10:57,460 --> 00:11:00,290 Anki jekk hemm b'mod ċar ħafna għalf ta 'jfixkluh up hemm. 236 00:11:00,290 --> 00:11:03,630 Imma ejja jieħdu l-affarijiet up a talja u jintroduċu din il-verżjoni, li tfakkar 237 00:11:03,630 --> 00:11:06,160 kienet it-tielet verżjoni li aħna spiċċajna bi aħħar darba. 238 00:11:06,160 --> 00:11:09,120 >> U issa hemm b'mod ċar żewġ użi ta 'printf. 239 00:11:09,120 --> 00:11:12,280 Hemm 2 sejħiet għall Alana f'dan il-każ għall printf, 240 00:11:12,280 --> 00:11:14,740 imma hemm ukoll sejħa lil funzjoni oħra. 241 00:11:14,740 --> 00:11:17,150 X'hemm dik il-funzjoni b'mod ċar? 242 00:11:17,150 --> 00:11:17,650 Getstring. 243 00:11:17,650 --> 00:11:18,980 >> Nistgħu tikseb wieħed voluntier aktar? 244 00:11:18,980 --> 00:11:20,980 OK, come fuq up. 245 00:11:20,980 --> 00:11:21,805 X'hemm isem tiegħek? 246 00:11:21,805 --> 00:11:22,990 >> JAVIER: Javier. 247 00:11:22,990 --> 00:11:24,750 >> DAVID Malan: Javier, come fuq up. 248 00:11:24,750 --> 00:11:27,270 Allura rwol Javier hu fuq din il-biċċa ta 'karta. 249 00:11:27,270 --> 00:11:28,860 Liema Jien ser sejħa ġenerikament s. 250 00:11:28,860 --> 00:11:32,250 Issa dan huwa varjabbli, huwa ta 'spag tip, kif implikat 251 00:11:32,250 --> 00:11:34,290 billi dan it-tieni linja fin-nofs hemm. 252 00:11:34,290 --> 00:11:36,540 U nixtieq li inti tmur tikseb me string. 253 00:11:36,540 --> 00:11:40,120 Speċifikament ras stabbiliti għall-orkestra taqsima u nikseb me l-isem ta 'xi ħadd, 254 00:11:40,120 --> 00:11:43,142 u terga 'lura ma' varjabbli fihom dak il-valur. 255 00:11:43,142 --> 00:11:44,225 Hija tista 'tkun xi ħadd inti tixtieq. 256 00:11:44,225 --> 00:11:47,590 257 00:11:47,590 --> 00:11:48,520 >> Here we go. 258 00:11:48,520 --> 00:11:53,620 259 00:11:53,620 --> 00:11:55,960 Kull dritt, Javier huwa kitba l-isem. 260 00:11:55,960 --> 00:12:02,210 261 00:12:02,210 --> 00:12:03,280 Kull dritt. 262 00:12:03,280 --> 00:12:05,740 Aħna kollha jistgħu probabbilment raden kif dan se play out. 263 00:12:05,740 --> 00:12:07,489 Aħna qed forsi belaboring il-punt ta 'dak 264 00:12:07,489 --> 00:12:10,320 funzjoni hija tagħmel, imma madankollu nirringrazzjak ħafna. 265 00:12:10,320 --> 00:12:13,890 >> Allura Javier marret lura din is-sekwenza hawnhekk, li, ma tistax pjuttost tara, 266 00:12:13,890 --> 00:12:15,800 Jonathan huwa l-sekwenza li konna gotten. 267 00:12:15,800 --> 00:12:18,330 Allura issa dak li jien attwalment għaddejjin biex jipprovdu lill Alana għalkemm 268 00:12:18,330 --> 00:12:20,150 hija xi ftit differenti. 269 00:12:20,150 --> 00:12:23,800 Minħabba f'dan il-verżjoni tal- programm, l-ewwel hemm jiddikjaraw l-isem tiegħek. 270 00:12:23,800 --> 00:12:26,160 Allura l-ewwel argument I bżonn li jipprovdu Alana 271 00:12:26,160 --> 00:12:33,030 ma se tkun litteralment jiddikjaraw l-isem tiegħek. 272 00:12:33,030 --> 00:12:35,280 Kull dritt, tant sempliċi bħal dik Nixtieq idejn dan lilek. 273 00:12:35,280 --> 00:12:36,730 U kif I write up tal- argument jmiss, jekk inti 274 00:12:36,730 --> 00:12:39,230 tixtieq li tmur quddiem u tikteb din fuq il-bord, ejja imorru quddiem 275 00:12:39,230 --> 00:12:42,659 u jagħmlu l-eżempju finali hawn biex jagħmlu ċar x'inhu finalment qbilna li jiġri. 276 00:12:42,659 --> 00:12:44,450 Allura jiddikjaraw l-isem tiegħek, tikteb lejn il-quċċata 277 00:12:44,450 --> 00:12:47,220 jekk inti ma mind, biss hekk li għandna kamra għat-tieni linja waħda. 278 00:12:47,220 --> 00:12:52,890 Minħabba li l-aħħar ħaġa jien ser li issa jagħtuk mhuwiex wieħed, 279 00:12:52,890 --> 00:12:57,220 iżda żewġ biċċiet tal-karti. 280 00:12:57,220 --> 00:12:58,074 >> Kull dritt. 281 00:12:58,074 --> 00:13:01,920 H-E-L-L-O virgola u imbagħad linja vojta. 282 00:13:01,920 --> 00:13:04,780 Allura dak li jien ser idejn Alana issa hija xi ftit differenti. 283 00:13:04,780 --> 00:13:08,600 Mhux biss hija hi jkollna dan, fejn Imla l-vojt tirrappreżenta 284 00:13:08,600 --> 00:13:12,050 li percent-- dak li kien l- placeholder aħna kont qed tuża? 285 00:13:12,050 --> 00:13:13,890 Yeah, hekk mija s. 286 00:13:13,890 --> 00:13:16,530 Sadanittant jien ser jgħaddu tagħha f'tieni argument, li 287 00:13:16,530 --> 00:13:19,290 huwa preċiżament dak Javier miksuba mill Jonathan. 288 00:13:19,290 --> 00:13:20,534 >> So let me jagħtuk dawn iż-żewġ. 289 00:13:20,534 --> 00:13:22,575 Jekk inti tixtieq li, imorru quddiem u print dak l-effett. 290 00:13:22,575 --> 00:13:25,660 291 00:13:25,660 --> 00:13:28,130 X'hemm finalment jiġri issa jiġifieri, Alana darb'oħra 292 00:13:28,130 --> 00:13:29,410 qed jilgħab l-irwol ta 'printf. 293 00:13:29,410 --> 00:13:32,160 Javier kien playing ir-rwol ta 'GetString. 294 00:13:32,160 --> 00:13:34,700 Allura li se jkun souvenir tiegħek. 295 00:13:34,700 --> 00:13:39,910 U finalment dak li qed jiġri, minkejja dan hello-- Yep imorru quddiem u virgola. 296 00:13:39,910 --> 00:13:41,410 Alana: Did I jirċievu dan jew għadhom ebda? 297 00:13:41,410 --> 00:13:43,451 DAVID Malan: Yep, inti riċevuta minnhom tnejn f'daqqa. 298 00:13:43,451 --> 00:13:45,740 Allura l-idea hija li inti issa jistgħu flip-paġna 299 00:13:45,740 --> 00:13:50,000 biex jimmaniġġaw it-tieni ta dawn iż-żewġ inputs. 300 00:13:50,000 --> 00:13:53,280 Allura dan huwa biss li martell-dar tal- punt li filwaqt Alana esegwiti 301 00:13:53,280 --> 00:13:55,830 din il-linja ħadra hawn, u mbagħad Javier għamlet dan wieħed għalina 302 00:13:55,830 --> 00:13:57,820 u r-ritorn lili xi ħaġa aħna ser sejħa i, imma kien verament 303 00:13:57,820 --> 00:13:59,520 biss li biċċa karta ta 'tiegħu stess. 304 00:13:59,520 --> 00:14:02,320 U issa Alana għamlet din it-tielet linja. 305 00:14:02,320 --> 00:14:06,010 >> U anki jekk dan kollu jistenna hekk oerhört cryptic forsi 306 00:14:06,010 --> 00:14:08,870 ewwel daqqa t'għajn, huwa verament huwa sempliċi bħal dik. 307 00:14:08,870 --> 00:14:11,390 Tgħaddi inputs madwar, jkollna outputs, jew 308 00:14:11,390 --> 00:14:14,560 qed fiżikament mogħtija lura xi ħaġa, jew jara effett sekondarju bħal dan. 309 00:14:14,560 --> 00:14:17,170 Xi ħaġa viżwalment miktub fuq l-iskrin. 310 00:14:17,170 --> 00:14:19,990 Mela ejja imorru quddiem u nirringrazzja Alana u Javier, 311 00:14:19,990 --> 00:14:25,012 li kien jistabbilixxi hawn, għal jingħaqdu magħna up here. 312 00:14:25,012 --> 00:14:25,934 >> [Applause] 313 00:14:25,934 --> 00:14:29,360 314 00:14:29,360 --> 00:14:33,480 >> Allura issa ejja jieħdu għal mogħtija kemm sempliċi kollha ta 'li jista' jkun. 315 00:14:33,480 --> 00:14:36,775 U ejja tipproċedi biex attwalment tagħmel xi ħaġa fil-kodiċi attwali. 316 00:14:36,775 --> 00:14:40,620 Allura up fuq l-iskrin hawnhekk hija screenshot tal-hekk imsejħa appliance CS50. 317 00:14:40,620 --> 00:14:43,980 U jekk inti kellha fuq, bħala 02:00 nhar l-Erbgħa wara nofsinhar, 318 00:14:43,980 --> 00:14:46,602 jispjegaw xi wħud ħabib dak l-appliance CS50 hija, 319 00:14:46,602 --> 00:14:48,185 kif kieku inti tiddefinixxi dan fil-sentenza? 320 00:14:48,185 --> 00:14:52,160 321 00:14:52,160 --> 00:14:53,240 Kwalunkwe sentenza waħda? 322 00:14:53,240 --> 00:14:54,876 Yeah? 323 00:14:54,876 --> 00:14:57,334 STUDENT: Huwa simili programm li jagħmel il-kompjuter ta 'kulħadd 324 00:14:57,334 --> 00:14:58,460 mmexxija bl-istess sistema. 325 00:14:58,460 --> 00:14:59,210 DAVID Malan: Tajba! 326 00:14:59,210 --> 00:15:02,810 Huwa programm li tippermetti li kulħadd kompjuter biex imexxu bl-istess sistema. 327 00:15:02,810 --> 00:15:04,920 Huwa tip ta 'tiegħek stess kopja ta 'operattiva 328 00:15:04,920 --> 00:15:07,540 sistema li jiġri jiġu msejħa Ubuntu Linux. 329 00:15:07,540 --> 00:15:11,070 U din tmur b'mod effettiv fi ħdan ta ' tieqa fuq Mac tiegħek stess jew PC, 330 00:15:11,070 --> 00:15:15,080 b'tali mod li dan il-mod id-dritt barra tal-bieb fil-ġimgħa 1, kulħadd hawn fil-klassi 331 00:15:15,080 --> 00:15:17,590 ikollu aċċess għall-istess għodod, l-istess konfigurazzjoni, 332 00:15:17,590 --> 00:15:21,250 u hemm ebda speċifiku kurva tat-tagħlim għal Mac jew PC b'mod partikolari. 333 00:15:21,250 --> 00:15:25,620 >> Issa aħna miftuħa up, ġewwa tal-CS50 appliance nhar it-Tnejn, dan il-programm hawn. 334 00:15:25,620 --> 00:15:27,040 Dan jiġri li għandu jissejjaħ gedit. 335 00:15:27,040 --> 00:15:29,050 Imma dak li verament ftit editur grafika. 336 00:15:29,050 --> 00:15:33,170 Hija xi ħaġa simili notepad jew Test Edit fuq Windows jew Mac OS rispettivament. 337 00:15:33,170 --> 00:15:36,720 And I propost li kien hemm verament tliet partijiet importanti għal dan l-iskrin. 338 00:15:36,720 --> 00:15:39,560 In-naħa ta 'fuq huwa fejn inti se jikteb kodiċi tiegħek. 339 00:15:39,560 --> 00:15:44,080 U li fejn aħna jintefqu ħafna ta 'tagħna tliet eżempji fil lecture nhar it-Tnejn. 340 00:15:44,080 --> 00:15:47,650 Il-bottom we called dak, dan il-tieqa iswed, yeah? 341 00:15:47,650 --> 00:15:48,640 >> STUDENT: kompilatur? 342 00:15:48,640 --> 00:15:51,500 >> DAVID Malan: kompilatur aħna aċċessata permezz ta 'dak tieqa. 343 00:15:51,500 --> 00:15:53,040 Iżda aktar ġenerali. 344 00:15:53,040 --> 00:15:54,540 Yeah, kien biss tieqa terminal. 345 00:15:54,540 --> 00:15:57,780 Dan huwa terminu antik età li biss jiddeskrivi essenzjalment Teptip 346 00:15:57,780 --> 00:16:01,910 pront, li snin ilu użat biex tkun fuq wieħed minn dawn il-monitors kbar stil CRT. 347 00:16:01,910 --> 00:16:04,300 Imma llum huwa tip ta virtwali fis-software. 348 00:16:04,300 --> 00:16:06,710 U l-twieqi tat-terminal Ejja us tip jikkmanda. 349 00:16:06,710 --> 00:16:11,750 Hija tip tal-verżjoni simplifikata tal-interface utent jew UI. 350 00:16:11,750 --> 00:16:14,060 Mhuwiex grafika interface utent jew GUI, 351 00:16:14,060 --> 00:16:17,250 huwa interface ibbażat fuq test jew interface kmand tal-linja. 352 00:16:17,250 --> 00:16:20,770 >> U fil-fatt li fejn finalment I kien kapaċi li jikteb xi kodiċi. 353 00:16:20,770 --> 00:16:24,200 Ladarba I kien kiteb xi kodiċi għalkemm, ifakkar li I użat dan il-kmand. 354 00:16:24,200 --> 00:16:26,210 U kif l-isem tip ta jissuġġerixxi, dan 355 00:16:26,210 --> 00:16:29,860 tippermetti lili biex tagħmel programm imsejjaħ Hello. 356 00:16:29,860 --> 00:16:33,400 Imma dak li kien verament tagħmel? 357 00:16:33,400 --> 00:16:36,180 Ukoll make kienet qed tieħu tiegħi input, kodiċi sors tiegħi, 358 00:16:36,180 --> 00:16:39,380 u dan jinbidel għal dak li, finalment? 359 00:16:39,380 --> 00:16:40,060 >> Object code. 360 00:16:40,060 --> 00:16:42,790 U l-kodiċi oġġett huwa biss fancy mod ta 'tgħid żerijiet u dawk. 361 00:16:42,790 --> 00:16:46,420 U mbagħad darba xtaqt biex imexxu dan il-kodiċi oġġett, 362 00:16:46,420 --> 00:16:50,940 ladarba jien ridt li jgħaddu bħala input dawk żerijiet u dawk fis-kompjuter tiegħi 363 00:16:50,940 --> 00:16:54,430 moħħ, il-CPU hekk imsejħa jew unità ċentrali ta 'pproċessar, 364 00:16:54,430 --> 00:16:55,730 I kellhom imexxu l-programm. 365 00:16:55,730 --> 00:16:59,042 Iżda dan ma kienx pjuttost sempliċi nhar it-Tnejn bħala sempliċiment double tikklikkja ftit ikona. 366 00:16:59,042 --> 00:17:01,375 What minflok ma I jkollhom biex jagħmlu sabiex tmexxi programm? 367 00:17:01,375 --> 00:17:04,130 368 00:17:04,130 --> 00:17:07,890 >> Liema kienet li t-tieni kmand? 369 00:17:07,890 --> 00:17:09,619 Jien smigħ slashes ftit? 370 00:17:09,619 --> 00:17:10,544 Iva, yeah? 371 00:17:10,544 --> 00:17:12,474 >> STUDENT: Dot mmejla u isem tal-programm. 372 00:17:12,474 --> 00:17:13,349 DAVID Malan: Eżattament. 373 00:17:13,349 --> 00:17:15,030 Dot mmejla u l-isem tal-programm. 374 00:17:15,030 --> 00:17:16,210 Issa dak li ma jfisser dan? 375 00:17:16,210 --> 00:17:19,470 Well dot huwa biss mod arcane ta 'tgħid direttorju kurrenti. 376 00:17:19,470 --> 00:17:23,440 Tkun xi tkun folder inti fil hija referenzjati bħala, huwa rappreżentat bħala dot. 377 00:17:23,440 --> 00:17:26,680 Il slash huwa biss dak li inti stajt tidher fil Mac OS u Windows għal snin, 378 00:17:26,680 --> 00:17:30,329 huwa separatur bejn direttorju jew folder u l-bqija ta 'xi isem. 379 00:17:30,329 --> 00:17:32,620 Fil-Windows dan jiġri li jmorru lura, fil-Linux u Mac 380 00:17:32,620 --> 00:17:34,210 OS dan jiġri li jmorru quddiem. 381 00:17:34,210 --> 00:17:37,560 Iżda huwa biss il-separatur, dan huwa biss dettall sintattika uninteresting. 382 00:17:37,560 --> 00:17:40,440 >> Il-parti mmerraq tal-kors huwa l-isem tal-programm, Hello. 383 00:17:40,440 --> 00:17:42,650 U dan huwa dak jagħmlu maħluqa għalina. 384 00:17:42,650 --> 00:17:44,910 Hija outputted dan il-fajl għalina. 385 00:17:44,910 --> 00:17:46,700 Imma kif ma nikbru dak il-punt? 386 00:17:46,700 --> 00:17:48,870 Ejja issa titlob lill- kwistjoni, dak li kien verament 387 00:17:48,870 --> 00:17:52,470 għaddejjin hawn, għall-inqas ma ' rigward ta 'xi wħud minn dan sintassi? 388 00:17:52,470 --> 00:17:57,000 >> Allura f'sentenza jew hekk, kif ma aħna jispjegaw bogħod 389 00:17:57,000 --> 00:17:59,020 dan l-ewwel linja li l- enfasizzat fl-aħdar? 390 00:17:59,020 --> 00:18:02,998 Liema kienet l-ewwel linja li tagħmel, fir-rigward programm tiegħi? 391 00:18:02,998 --> 00:18:03,974 Yeah? 392 00:18:03,974 --> 00:18:05,067 >> STUDENT: [inaudible]. 393 00:18:05,067 --> 00:18:06,150 DAVID Malan: Say mill-ġdid? 394 00:18:06,150 --> 00:18:08,734 STUDENT: Inklużi u tniżżil funzjonijiet tal-passat [inaudible]. 395 00:18:08,734 --> 00:18:09,483 DAVID Malan: Tajba. 396 00:18:09,483 --> 00:18:11,900 Inklużi, I mhux se ngħid tniżżil, imma ejja ngħidu 397 00:18:11,900 --> 00:18:15,500 inklużi funzjonijiet li n-nies kitbu fil-passat. 398 00:18:15,500 --> 00:18:18,260 U dawk il-funzjonijiet jiġu implimentati x'imkien fil-kompjuter tiegħi. 399 00:18:18,260 --> 00:18:20,470 Xi ħadd kiteb fajl snin ilu, u dan il-fajl 400 00:18:20,470 --> 00:18:23,490 huwa x'imkien ġewwa tal-CS50 appliance, jew fuq hard drive tiegħi 401 00:18:23,490 --> 00:18:24,480 b'mod aktar ġenerali. 402 00:18:24,480 --> 00:18:27,810 U għalhekk din il-linja huwa essenzjalment qal, mur isibu dan il-fajl, I standard / O dot 403 00:18:27,810 --> 00:18:31,740 h, u kopja u paste kontenut tiegħu dritt hawn fuq il-quċċata tal-fajl tiegħi 404 00:18:31,740 --> 00:18:33,860 I hekk li ma jkollhom tagħmel dan manwalment myself. 405 00:18:33,860 --> 00:18:40,970 >> U fost il-biċċiet juiciest ġewwa ta dan il-fajl aħna mitluba kienet liema funzjoni? 406 00:18:40,970 --> 00:18:45,740 What funzjoni ma ngħidu kien iddikjarat jew imsemmija fl-I standard / O dot h 407 00:18:45,740 --> 00:18:47,120 aktar probabbli? 408 00:18:47,120 --> 00:18:47,900 Printf, id-dritt? 409 00:18:47,900 --> 00:18:50,797 Aħna ma jiktbu printf fuq It-Tnejn, hija biss teżisti. 410 00:18:50,797 --> 00:18:52,880 Ferm simili Alana biss daħal up fuq il-palk u hi biss 411 00:18:52,880 --> 00:18:55,540 teżisti u kien jaf kif tfassal xi ħaġa fuq l-iskrin, 412 00:18:55,540 --> 00:18:58,660 hekk ma printf jeżistu għal ħafna snin. 413 00:18:58,660 --> 00:19:00,240 U hekk dan huwa kif aħna jkollhom aċċess għaliha. 414 00:19:00,240 --> 00:19:03,280 Issa jekk aħna jimxu fuq hawn, ewlieni kien analoga aħna 415 00:19:03,280 --> 00:19:06,620 qal li l-biċċa puzzle imsejħa meta bandiera aħdar għafast 416 00:19:06,620 --> 00:19:07,620 fid-dinja ta 'Scratch. 417 00:19:07,620 --> 00:19:10,130 Huwa biss tip ta 'l- isem default li l-bnedmin 418 00:19:10,130 --> 00:19:13,340 iddeċieda jirrappreżenta l- default punt ta 'dħul għal programm. 419 00:19:13,340 --> 00:19:16,540 Il blokki ta 'kodiċi ta' programmazzjoni li gets esegwiti ewwel. 420 00:19:16,540 --> 00:19:19,700 >> Sadanittant dawn braces kaboċċi huma tip ta bħall-forma mgħawġa 421 00:19:19,700 --> 00:19:21,410 ta 'lott ta' dawk il-biċċiet scratch isfar. 422 00:19:21,410 --> 00:19:24,860 Huma tip ta jirrappreżentaw kollu mazz ta 'struzzjonijiet flimkien. 423 00:19:24,860 --> 00:19:28,350 Allura hija biss tip ta 'torbot flimkien xi funzjonalità relatati. 424 00:19:28,350 --> 00:19:33,750 printf tal-kors huwa funzjoni li prints l-iskrin, kif aħna biss għamlet. 425 00:19:33,750 --> 00:19:35,190 >> What dwar dawn parentesi? 426 00:19:35,190 --> 00:19:38,770 Kif inti define-- anki jekk inti stajt qatt programmati qabel, iżda biss ibbażat 427 00:19:38,770 --> 00:19:41,320 issa fuq tiżdied intwizzjoni wieħed jittama, liema 428 00:19:41,320 --> 00:19:43,290 huma l-parentesi jagħmlu għalina hawn? 429 00:19:43,290 --> 00:19:45,450 Jew liema huma madwar? 430 00:19:45,450 --> 00:19:46,360 Yeah? 431 00:19:46,360 --> 00:19:49,360 >> STUDENT: Huma qed tgħid liema int ser jistampaw bil printf. 432 00:19:49,360 --> 00:19:52,401 >> DAVID Malan: Yeah, dawn qed tgħid dak int ser jistampaw bil printf. 433 00:19:52,401 --> 00:19:56,260 Jew b'mod iktar ġenerali, huma jdawwar l-inputs għall-funzjoni. 434 00:19:56,260 --> 00:19:58,530 Allura inti tista 'kważi taħseb ta 'dawk parentesi 435 00:19:58,530 --> 00:20:01,620 bħala bħall-metall clip fuq din clipboard. 436 00:20:01,620 --> 00:20:05,940 Huwa x'hemm azjenda, huwa x'hemm ser jintużaw biex jipprovdu argumenti 437 00:20:05,940 --> 00:20:08,500 fil-funzjoni, li F'dan il-każ huwa msejjaħ printf. 438 00:20:08,500 --> 00:20:12,390 >> Allura b'mod ġenerali kważi kull ħin nitolbu funzjoni, 439 00:20:12,390 --> 00:20:14,280 aħna ser tara parentesi par. 440 00:20:14,280 --> 00:20:17,000 Forsi ma 'xi ħaġa fiha, bħal issa, forsi xejn fiha. 441 00:20:17,000 --> 00:20:19,770 Imma dak li fejn inti tpoġġi l-inputs jew hekk imsejħa argumenti 442 00:20:19,770 --> 00:20:20,680 għal funzjoni. 443 00:20:20,680 --> 00:20:22,470 >> Hawn argument wieħed bħal dawn. 444 00:20:22,470 --> 00:20:24,467 Stajt enfasizzat kollox bejn il-kwotazzjonijiet, 445 00:20:24,467 --> 00:20:26,300 għaliex jirriżulta f'din il-lingwa imsejħa 446 00:20:26,300 --> 00:20:29,950 C, meta inti tixtieq li tirrappreżenta string-- li hija kelma jew frażi 447 00:20:29,950 --> 00:20:33,470 jew saħansitra paragraph-- għandek madwaru ma kwotazzjonijiet doppja. 448 00:20:33,470 --> 00:20:35,420 Kwotazzjonijiet Mhux wieħed, kwotazzjonijiet doppja. 449 00:20:35,420 --> 00:20:37,460 U dan huwa eżattament dak I ghamilt hawn. 450 00:20:37,460 --> 00:20:39,900 >> Sadanittant hemm funky simbolu lejn it-tmiem hemmhekk. 451 00:20:39,900 --> 00:20:41,600 Il n backslash. 452 00:20:41,600 --> 00:20:43,460 What did aħna ngħidu li irrappreżentata? 453 00:20:43,460 --> 00:20:44,093 Yeah? 454 00:20:44,093 --> 00:20:44,980 >> STUDENT: A linja ġdida. 455 00:20:44,980 --> 00:20:45,896 >> DAVID Malan: Linja Ġdid. 456 00:20:45,896 --> 00:20:47,910 Dritt, inti ma ġeneralment hit Ikteb meta 457 00:20:47,910 --> 00:20:50,430 trid li l-programm bżiq out linja ġdida. 458 00:20:50,430 --> 00:20:54,210 Pjuttost inti tgħid b'mod espliċitu ma din il-biċċa ċertament arcane 459 00:20:54,210 --> 00:20:58,770 ta sintassi, backslash n, li inti tixtieq linja ġdida li jmorru hemm. 460 00:20:58,770 --> 00:20:59,810 Fl-aħħarnett l-virgola. 461 00:20:59,810 --> 00:21:01,560 Aħna ma verament jitkellmu wisq dwar dan, 462 00:21:01,560 --> 00:21:04,893 u bil-bosta dan se jkun l-bane ta 'xi tal-eżistenza tiegħek għall-ewwel problema 463 00:21:04,893 --> 00:21:07,990 sett, meta inti biss naqset li tirrealizza inti stajt minsija xi ħaġa bħala stupid 464 00:21:07,990 --> 00:21:08,614 bħala virgola. 465 00:21:08,614 --> 00:21:11,600 U ġeneralment tqegħid se jiffissaw hemm dik il-problema. 466 00:21:11,600 --> 00:21:13,511 Imma x'hemm dan isir għalina, would you say? 467 00:21:13,511 --> 00:21:15,670 >> STUDENT: [inaudible]. 468 00:21:15,670 --> 00:21:17,484 >> DAVID Malan: Jiddispjacini? 469 00:21:17,484 --> 00:21:18,532 >> STUDENT: [inaudible]. 470 00:21:18,532 --> 00:21:19,990 DAVID Malan: Irfinar dikjarazzjoni. 471 00:21:19,990 --> 00:21:22,770 Huwa tip ta bħall-perjodu fuq l-aħħar ta 'sentenza Ingliża, 472 00:21:22,770 --> 00:21:25,790 billi f'din il-lingwa C huwa jispiċċa dikjarazzjoni. 473 00:21:25,790 --> 00:21:29,250 L-istruzzjoni ta 'programmazzjoni kodiċi li inti biss jridu jgħidu, 474 00:21:29,250 --> 00:21:30,500 Jien jsir ma 'dan. 475 00:21:30,500 --> 00:21:32,240 Issa avviż li l-uniku wieħed hawn. 476 00:21:32,240 --> 00:21:34,614 Allura inti ma tridx li tikseb fl drawwa ta 'semicolons tqegħid 477 00:21:34,614 --> 00:21:36,190 wara kull parentesi magħluqa. 478 00:21:36,190 --> 00:21:38,610 Per eżempju hemm xejn jmiss null, u aħna ser 479 00:21:38,610 --> 00:21:40,430 terga 'lura fil-futur għal dak mezzi null. 480 00:21:40,430 --> 00:21:44,080 Iżda f'dan il-każ printf tiegħek huwa funzjoni, jew dikjarazzjoni qed jintużaw, 481 00:21:44,080 --> 00:21:47,420 u hekk aħna tixtieq li jkollok li terminus fl-aħħar nett ta 'dan. 482 00:21:47,420 --> 00:21:50,980 >> U jien intenzjonalment picking fuq C. U franchement ħafna ta 'lingwi bħal C, C ++ 483 00:21:50,980 --> 00:21:55,000 Java, JavaScript, u ​​kull numru ta ' f'ilsna oħra għandhom ħafna ta 'dawn 484 00:21:55,000 --> 00:21:56,730 tip ta 'dettalji sintattika. 485 00:21:56,730 --> 00:22:00,120 Li ċertament jekk int ġodda biex programmazzjoni jistgħu ġenwinament vjaġġ inti up. 486 00:22:00,120 --> 00:22:02,307 U int se, jimmarkaw tiegħi kliem, xi wħud minnkom se 487 00:22:02,307 --> 00:22:04,140 jkollhom din l-esperjenza fil-ħinijiet uffiċċju jew tard 488 00:22:04,140 --> 00:22:07,554 bil-lejl jaħdmu fuq xi p-set, fejn program kkritikat tiegħek biss ma tiġborx, 489 00:22:07,554 --> 00:22:09,470 ma tmurx, inti għandek ebda idea x'hemm ħażin, 490 00:22:09,470 --> 00:22:11,513 jidher kompletament loġikament korretta għalik. 491 00:22:11,513 --> 00:22:13,596 U huwa għaliex inti nesa xi ħaġa bħal laqtu 492 00:22:13,596 --> 00:22:15,250 semicolon fl-aħħar ta 'xi linja. 493 00:22:15,250 --> 00:22:17,590 >> Iżda dawn huma t-tipi ta 'affarijiet int ser jitgħallmu immedjatament biex tara. 494 00:22:17,590 --> 00:22:20,048 U fil-fatt dawn huma l-affarijiet li u TF tal-CA jkollhom 495 00:22:20,048 --> 00:22:23,210 ġie tip ta imħarrġa biex tara ħafna aktar malajr milli suppost. 496 00:22:23,210 --> 00:22:26,610 U hekk dan huwa biss li jgħidu, kif inti adsa fis-problema stabbilixxa l-1 speċjalment, 497 00:22:26,610 --> 00:22:28,217 ma jsibux frustrati minn dan il-għalf. 498 00:22:28,217 --> 00:22:30,050 Ladarba inti tip ta 'aklimatizza għad-dinja, inti 499 00:22:30,050 --> 00:22:35,130 tibda tara affarijiet li inti tista 'ma tara ewwel daqqa t'għajn din l-ewwel ġimgħa. 500 00:22:35,130 --> 00:22:37,440 >> Allura kodiċi sors hija xi ħaġa bħal dik. 501 00:22:37,440 --> 00:22:40,370 Aħna rridu li għaddih fil l-hekk imsejħa kompilatur. 502 00:22:40,370 --> 00:22:42,850 U li kompilatur bħala għidna jipprovdi output 503 00:22:42,850 --> 00:22:45,660 magħrufa bħala kodiċi oġġett, il- żerijiet u dawk hekk imsejħa. 504 00:22:45,660 --> 00:22:47,747 Iżda minn hemm, dak li ma tagħtina? 505 00:22:47,747 --> 00:22:49,080 Ukoll huwa jagħtina dawn it-tendenzi. 506 00:22:49,080 --> 00:22:52,020 U għal darb'oħra kompjuter tiegħek, Intel tiegħek ġewwa, 507 00:22:52,020 --> 00:22:54,350 jifhem dawn it-tendenzi ta 'żerijiet u dawk. 508 00:22:54,350 --> 00:22:57,300 U xi kultant l-mudell jirrappreżenta numru deċimali attwali 509 00:22:57,300 --> 00:22:59,770 kif rajna aħħar ġimgħa, xi kultant dan jirrappreżenta ittra 510 00:22:59,770 --> 00:23:02,730 bħal rajna aħħar ġimgħa, xi kultant dan jirrappreżenta istruzzjoni, 511 00:23:02,730 --> 00:23:05,460 bħal istampar xi ħaġa li l-iskrin. 512 00:23:05,460 --> 00:23:08,782 >> Allura printf għall instance-- iżda pjuttost, let me kontrina. 513 00:23:08,782 --> 00:23:11,240 Imxejna ilhom jieħdu għall mogħtija li dawk żerijiet u dawk li huma 514 00:23:11,240 --> 00:23:14,200 prodotta minn dan il-kmand make. 515 00:23:14,200 --> 00:23:16,050 Imma kun mhix kompilatur. 516 00:23:16,050 --> 00:23:19,370 Agħmel mhuwiex il-ħaġa fin-nofs thats tipproduċi l-żerijiet u dawk. 517 00:23:19,370 --> 00:23:23,780 Pjuttost tagħmel huwa biss konvenjenti ħafna programm jismu li l-iskop fil-ħajja 518 00:23:23,780 --> 00:23:27,267 huwa essenzjalment biex insemmu kif jikkompilaw program tiegħek. 519 00:23:27,267 --> 00:23:29,350 U nużawha f'dawn ewwel ġimgħat għaliex hija biss 520 00:23:29,350 --> 00:23:30,910 jiffranka us ħafna problemi. 521 00:23:30,910 --> 00:23:34,080 >> Imma dak li jagħmlu huwa verament tagħmel meta inti tiġbor hello, 522 00:23:34,080 --> 00:23:36,690 hija, kif aħna qal aħħar darba, huwa tfittex fuq hard drive tiegħek 523 00:23:36,690 --> 00:23:40,620 jew fil-folder attwali, għal fajl imsejħa dak, apparentement? 524 00:23:40,620 --> 00:23:41,815 Hello.c, id-dritt? 525 00:23:41,815 --> 00:23:43,190 Li jinsab biss tip ta 'konvenzjoni. 526 00:23:43,190 --> 00:23:45,620 Huwa arbitrarja, iżda li l-mod l-affarijiet huma. 527 00:23:45,620 --> 00:23:48,620 Agħmel, jekk inti biss tispeċifika l-isem ta 'programm li għadha ma teżistix, 528 00:23:48,620 --> 00:23:52,200 li għaddej biex tfittex għall-kodiċi sors fil-fajl, fil-kontumaċja mezzi hello.c. 529 00:23:52,200 --> 00:23:53,530 U jekk isibha, kbir. 530 00:23:53,530 --> 00:23:56,650 Huwa ser jikkonvertu dak is-sors kodiċi fis object code għalik. 531 00:23:56,650 --> 00:23:59,670 >> Imma kull darba stajt hit Ikteb wara running jagħmlu hello, 532 00:23:59,670 --> 00:24:03,560 Tiftakar tara l-aħħar darba pjuttost twil u s-sekwenza cryptic 533 00:24:03,560 --> 00:24:06,430 ta 'ittri abjad ieħor u karattri fuq l-iskrin? 534 00:24:06,430 --> 00:24:11,220 Ukoll li kien l-kmand attwali, il- kompilatur attwali, li kien għaddej. 535 00:24:11,220 --> 00:24:15,500 Allura l-kumpilatur attwali aħna ser tuża aktar ta ' l-semestru hija xi ħaġa imsejħa clang. 536 00:24:15,500 --> 00:24:19,280 Xi wħud minnkom jista 'jkollok użati Visual Studio qabel, jew GCC, 537 00:24:19,280 --> 00:24:21,340 jew kwalunkwe numru ta 'kompilaturi oħra. 538 00:24:21,340 --> 00:24:22,620 Aħna ser tuża clang. 539 00:24:22,620 --> 00:24:26,950 >> U clang jippermetti li attwalment jikkonvertu dan il-kodiċi sors li toġġezzjona kodiċi. 540 00:24:26,950 --> 00:24:29,430 X'jagħmel din attwalment tfisser fil-prattika? 541 00:24:29,430 --> 00:24:33,390 Well let me go f'waħda minn folders tiegħi mill-aħħar darba. 542 00:24:33,390 --> 00:24:35,760 Ġewwa tal-appliance CS50. 543 00:24:35,760 --> 00:24:42,080 U let me imorru quddiem u joħolqu din istess fajl, jinkludu standard I / O dot h. 544 00:24:42,080 --> 00:24:42,875 Null prinċipali Int. 545 00:24:42,875 --> 00:24:46,000 U aħna ser terga 'lura fil-futur bħala għal dak li int mezzi u liema mezzi null. 546 00:24:46,000 --> 00:24:49,130 Iżda għal issa ejja do bonjour backslash dinja n, 547 00:24:49,130 --> 00:24:50,500 bħad għamilna fuq il-bord. 548 00:24:50,500 --> 00:24:53,930 >> Let me tiffranka dan il-fajl imsejħa hello.c. 549 00:24:53,930 --> 00:24:58,280 U issa jekk irrid li jiġbor dan I could-- let me zoom run in-- 550 00:24:58,280 --> 00:25:00,450 jagħmlu bonjour jidħol. 551 00:25:00,450 --> 00:25:02,645 U dan kien għal darb'oħra dik il-linja cryptic ħafna. 552 00:25:02,645 --> 00:25:05,120 Imma kelma issa mill-inqas wieħed probabbilment jumps fil inti. 553 00:25:05,120 --> 00:25:07,087 Clang hija dik il-linja rajna qabel. 554 00:25:07,087 --> 00:25:10,420 Issa hemm ħafna ta 'għalf ieħor franchement li aħna ser mewġa idejn tagħna fuq għal-lum. 555 00:25:10,420 --> 00:25:14,020 Iżda hemm sottogruppi ftit, ftit karattri fil hawn 556 00:25:14,020 --> 00:25:14,907 li huma ta 'interess. 557 00:25:14,907 --> 00:25:16,490 Imma jien ser jimxi 'l quddiem u jagħmlu dan. 558 00:25:16,490 --> 00:25:18,281 Jien ser ewwel ġirja hello, just biex jipprova 559 00:25:18,281 --> 00:25:20,320 li dan qed taħdem kif kien it-Tnejn. 560 00:25:20,320 --> 00:25:22,330 Imma issa jien ser tħassar il-programm. 561 00:25:22,330 --> 00:25:25,870 U ħafna bħal kellna dawn ismijiet qasir aħħar darba, 562 00:25:25,870 --> 00:25:29,787 il-kmand għat-tneħħija xi ħaġa hija rm, neħħi, jidħol. 563 00:25:29,787 --> 00:25:31,870 Inti qed tmur biex tikseb xi mistoqsijiet pjuttost cryptic. 564 00:25:31,870 --> 00:25:35,210 Hard biex jemmnu li inti tista 'tagħmel anki din il-kwistjoni diffiċli biex jifhmu. 565 00:25:35,210 --> 00:25:38,100 Iżda neħħi bonjour fajl regolari biss mezzi do inti tixtieq li tħassar bonjour. 566 00:25:38,100 --> 00:25:42,650 >> And I tista 'tmur quddiem u t-tip y għal iva, Ikteb, u issa marret. 567 00:25:42,650 --> 00:25:45,130 X'inhu dan ifisser issa, jekk I ċar l-iskrin tiegħi, 568 00:25:45,130 --> 00:25:47,301 hija li minflok tagħmel tagħmel hello-- inti 569 00:25:47,301 --> 00:25:48,800 taf liema, jien jkollna tajba fuq dan. 570 00:25:48,800 --> 00:25:50,690 Jien ser imexxu l-kompilatur myself. 571 00:25:50,690 --> 00:25:53,330 I m'għandhomx bżonn xi programm biex ċifra barra dak file tiegħi huwa msejjaħ. 572 00:25:53,330 --> 00:25:55,370 I kiteb hello.c, I jafu liema huwa msejjaħ, 573 00:25:55,370 --> 00:25:57,640 Jien b'mod ċar li jista 'ittajpjar dak. 574 00:25:57,640 --> 00:26:02,620 So I m ser jimxi 'l quddiem u ma clang hello.c Ikteb. 575 00:26:02,620 --> 00:26:03,264 >> Jidher li qed jaħdem. 576 00:26:03,264 --> 00:26:05,930 U hemm l-ebda output addizzjonali, minħabba clang huwa l-kumpilatur. 577 00:26:05,930 --> 00:26:08,590 Huwa x'hemm konverżjoni tal- kodiċi tas-sors għall-żerijiet u dawk. 578 00:26:08,590 --> 00:26:12,870 Mela jekk jien issa do dot mmejla bonjour Ikteb, hm. 579 00:26:12,870 --> 00:26:14,630 Messaġġ ġdid żball llum. 580 00:26:14,630 --> 00:26:17,610 Allura bash huwa biss l-isem tal- Teptip fil-pront li aħna qed tuża. 581 00:26:17,610 --> 00:26:20,360 Li l-oversimplification gross, iżda għal issa li kollox jiġifieri, 582 00:26:20,360 --> 00:26:21,401 huwa l-pront Teptip. 583 00:26:21,401 --> 00:26:22,880 U hu għalhekk li huwa yelling fil us. 584 00:26:22,880 --> 00:26:25,690 >> Nru tali file jew direttorju huwa ftit aktar sempliċi. 585 00:26:25,690 --> 00:26:28,190 Iżda żgur I magħmula dan il-kodiċi oġġett. 586 00:26:28,190 --> 00:26:30,930 Iżda l-qabda hija, li jekk I tip-kmand 587 00:26:30,930 --> 00:26:34,650 biex jelenkaw il-kontenut ta 'dan direttorju, li huwa dak? 588 00:26:34,650 --> 00:26:36,210 ls għall-lista. 589 00:26:36,210 --> 00:26:39,332 Hemm mazz ta 'għalf fil hawn, li wħud minnhom daħal mal-appliance, 590 00:26:39,332 --> 00:26:42,040 bħal folder Desktop tiegħi, Downloads folder, folder Dropbox, u kollha 591 00:26:42,040 --> 00:26:42,850 li Jittieħed. 592 00:26:42,850 --> 00:26:45,410 Imma dak li hu interessanti huwa hello.c, li 593 00:26:45,410 --> 00:26:47,286 I ħolqot mument ilu ma gedit. 594 00:26:47,286 --> 00:26:49,160 U x'inhu l-weirdest tfittex isem fil hawn, 595 00:26:49,160 --> 00:26:53,110 forsi li aħna ma ara l-aħħar ħin kollu? 596 00:26:53,110 --> 00:26:54,710 >> a.out, id-dritt? 597 00:26:54,710 --> 00:26:56,920 Allura lura fil-ġurnata, huwa li kien biss iddeċieda meta 598 00:26:56,920 --> 00:26:58,760 inti tikkompila programm għall-ewwel darba, 599 00:26:58,760 --> 00:27:02,360 u inti ma tispeċifika l-isem ta 'fajl, ejja sejħa hija. 600 00:27:02,360 --> 00:27:05,800 U a.out ifisser biss dan kien l-output tal-kompilatur. 601 00:27:05,800 --> 00:27:07,790 Allura huwa isem horrible għal programm. 602 00:27:07,790 --> 00:27:12,820 Iżda billi li l-loġika, dot mmejla għal direttorju kurrenti, mmejla a.out, 603 00:27:12,820 --> 00:27:16,102 għandu jfisser hemm fil-fatt tiegħi bonjour programm dinja. 604 00:27:16,102 --> 00:27:17,560 Issa ftit tisħon eżerċizzju, wisq. 605 00:27:17,560 --> 00:27:20,420 Jekk irrid li tibdel isem din fajl, jirriżulta li inti 606 00:27:20,420 --> 00:27:23,000 jimxu fajl mill-isem wieħed għall-ieħor. 607 00:27:23,000 --> 00:27:28,750 A.out Allura mv, u mbagħad I tista 'sejħa hija bonjour Ikteb. 608 00:27:28,750 --> 00:27:30,940 Allura dan huwa kmand Linux. 609 00:27:30,940 --> 00:27:34,370 DOS kellhom din snin ilu, Windows għandu tieqa terminal 610 00:27:34,370 --> 00:27:36,460 ta 'xi tip li jistenna bħal dan, Linux u Mac 611 00:27:36,460 --> 00:27:38,140 kompjuters għandhom dan Teptip fil-pront. 612 00:27:38,140 --> 00:27:41,490 Anke jekk ħafna minna probabbilment rarament, jekk qatt, tużah. 613 00:27:41,490 --> 00:27:44,590 >> Imma dak I ghamilt huwa mmexxi programm, li ismu huwa mv, 614 00:27:44,590 --> 00:27:47,900 u stajt sakemm dan ma żewġ argumenti, biex ngħidu hekk. 615 00:27:47,900 --> 00:27:48,630 Żewġ inputs. 616 00:27:48,630 --> 00:27:50,260 a.out huwa l-isem oriġinali. 617 00:27:50,260 --> 00:27:51,630 Hello huwa l-isem il-ġdid. 618 00:27:51,630 --> 00:27:55,670 Mela jekk jien issa do dot mmejla hello, Ikteb, li jeżisti. 619 00:27:55,670 --> 00:28:00,770 U jekk I do a.out dot mmejla, dak li tistenna I tara? 620 00:28:00,770 --> 00:28:02,250 >> Bash, ebda tali file jew direttorju. 621 00:28:02,250 --> 00:28:03,350 Minħabba I biss semmieh. 622 00:28:03,350 --> 00:28:04,975 Allura dan jieħu daqsxejn ta 'jkollna użati biex. 623 00:28:04,975 --> 00:28:06,977 Iżda l-problema stabbilixxa l-1 ispeċifikazzjoni ser verament 624 00:28:06,977 --> 00:28:08,810 żżomm f'idejk permezz xi ftit minn din minutae. 625 00:28:08,810 --> 00:28:11,050 Minħabba li dan huwa kompleta distrazzjoni intellettwali 626 00:28:11,050 --> 00:28:12,966 mill-aktar interessanti ideat fil-idejn, li 627 00:28:12,966 --> 00:28:15,310 huwa attwalment joħolqu xi ħaġa ta 'kodiċi. 628 00:28:15,310 --> 00:28:18,830 Imma ejja do modifika waħda issa biex dan il-programm. 629 00:28:18,830 --> 00:28:23,150 >> Ifakkar li l-aħħar darba għamilt xi ħaġa bħal dan, printf jiddikjaraw l-isem tiegħek. 630 00:28:23,150 --> 00:28:25,790 U fil-fatt aħna biss ma dan fuq il-big screen hemmhekk. 631 00:28:25,790 --> 00:28:30,640 U mbagħad I ma string s gets GetString paren miftuħa, paren qrib. 632 00:28:30,640 --> 00:28:33,430 U paren biss shorthand notazzjoni għall parentesi. 633 00:28:33,430 --> 00:28:36,460 Allura ma GetString tieħu ebda argument? 634 00:28:36,460 --> 00:28:38,440 Ebda inputs ebda, iżda teħtieġ l-parentesi, 635 00:28:38,440 --> 00:28:41,830 għaliex dan huwa dak tiddemarka l-sejħa ta 'funzjoni. 636 00:28:41,830 --> 00:28:46,440 >> So jien ser jimxi 'l quddiem u jippruvaw imexxu l-kumpilatur fuq dan il-programm issa. 637 00:28:46,440 --> 00:28:50,774 Hello.c Clang, minħabba I ma biddlitx l-isem tagħha għal issa. 638 00:28:50,774 --> 00:28:51,940 U sibt mazz ta 'żbalji. 639 00:28:51,940 --> 00:28:53,570 Ejja zoom out here. 640 00:28:53,570 --> 00:28:55,420 Jekk I iscroll up again, bħal I said aħħar darba, 641 00:28:55,420 --> 00:28:58,420 l-ewwel, l-istess żball li sibt aħħar darba. 642 00:28:58,420 --> 00:29:04,210 On-line 6 ta hello.c kelli string identifikatur mhux iddikjarat, 643 00:29:04,210 --> 00:29:05,590 ma I tfisser standard fil? 644 00:29:05,590 --> 00:29:06,750 I ma. 645 00:29:06,750 --> 00:29:10,050 Minħabba dak żball jkollhom I magħmula f'din programm, jekk inti recall minn aħħar darba? 646 00:29:10,050 --> 00:29:13,219 647 00:29:13,219 --> 00:29:15,010 Yeah, għandna bżonn l- hekk imsejħa roti taħriġ 648 00:29:15,010 --> 00:29:16,510 li aħna ser tuża biss għal ftit ġimgħat. 649 00:29:16,510 --> 00:29:19,480 Imma I bżonn li jiġi speċifikat li wkoll, x'imkien ġewwa tal-appliance, 650 00:29:19,480 --> 00:29:22,720 huwa fajl li aħna kiteb biss ftit snin ilu. 651 00:29:22,720 --> 00:29:26,500 Ġewwa minnhom huma funzjonijiet bħal apparentament GetString. 652 00:29:26,500 --> 00:29:35,160 Allura issa jekk immur lura stabbiliti hawn, zoom fi, u hello.c clang run mill-ġdid. 653 00:29:35,160 --> 00:29:36,500 Indanna, żball ieħor. 654 00:29:36,500 --> 00:29:38,590 Iżda aħna ma bbenefikawx dan wieħed qabel. 655 00:29:38,590 --> 00:29:41,900 >> Dan wieħed huwa ftit aktar esoteric biex insemmu. 656 00:29:41,900 --> 00:29:46,910 Iżda din hija deliberatament fuq l-iskrin, għaliex ridna li tgħid din l-istorja. 657 00:29:46,910 --> 00:29:51,280 Meta inti tikkompila hello.c, eżatt kif l-istampa minn ssuġġerit qabel, 658 00:29:51,280 --> 00:29:54,650 int biss konverżjoni li kodiċi tas-sors għall-żerijiet u dawk. 659 00:29:54,650 --> 00:30:00,340 Issa persunal CS50 ftit snin ilu kiteb CS50.h, u fajl korrispondenti, 660 00:30:00,340 --> 00:30:01,640 CS50.c. 661 00:30:01,640 --> 00:30:04,490 U aħna, ftit snin ilu, kkompilata dawn il-fajls 662 00:30:04,490 --> 00:30:07,290 fis-fajl li jiġri li għandu jissejjaħ CS50.o. 663 00:30:07,290 --> 00:30:09,180 >> Jew jista 'jkun isem ġdid ta' ftit affarijiet differenti. 664 00:30:09,180 --> 00:30:11,054 Imma dak mod sempliċi ta 'ħsieb dwar dan. 665 00:30:11,054 --> 00:30:14,960 Allura aħna ikkumpilata l CS50 librerija fis żerijiet u dawk. 666 00:30:14,960 --> 00:30:20,340 Imma mkien jiena speċifikati li nixtieq li jikkombinaw zeroes tiegħi 667 00:30:20,340 --> 00:30:24,030 u dawk għall-dinja bonjour tiegħi programm ma 'l-żerijiet u dawk 668 00:30:24,030 --> 00:30:29,760 li l-persunal CS50 ħoloq ftit snin ilu fis programm sħiħ wieħed. 669 00:30:29,760 --> 00:30:34,100 All I ve speċifikat mill-kitba hello.c clang huwa jikkompilaw hello.c. 670 00:30:34,100 --> 00:30:38,380 >> Stajt ma qallek clang biex link fil-żerijiet u dawk 671 00:30:38,380 --> 00:30:41,650 li l-persunal CS50 maħluqa għalik xi żmien ilu. 672 00:30:41,650 --> 00:30:48,280 Allura huwa jiffissaw faċli, sing l għal link, CS50. 673 00:30:48,280 --> 00:30:52,600 U aħna ser darb'oħra tara dan qabel twil darb'oħra u għal darb'oħra. 674 00:30:52,600 --> 00:30:54,420 Imma avviż issa ma kien hemm l-ebda ilmenti. 675 00:30:54,420 --> 00:30:59,770 Allura issa jekk I run dot mmejla hello, issa huwa xogħol. 676 00:30:59,770 --> 00:31:03,840 Għalkemm dan huwa daqsxejn qarrieqa peress I biss recreated dak fajl? 677 00:31:03,840 --> 00:31:05,880 a.out. 678 00:31:05,880 --> 00:31:07,930 >> So let me Rewind għal ftit mument. 679 00:31:07,930 --> 00:31:10,900 Il-programm aħna biss kkompilata għandu tliet linji ta 'kodiċi. 680 00:31:10,900 --> 00:31:14,710 Meta I dam bonjour dinja, bonjour mument ilu, I ma tara tiddikjara l-isem tiegħek. 681 00:31:14,710 --> 00:31:17,080 U dan għaliex I dam l- verżjoni l-qadima tal-programm. 682 00:31:17,080 --> 00:31:22,700 Imma jekk jien tassew run a.out dot mmejla Daħħal, jiddikjaraw l-isem tiegħek, Rob, hello, 683 00:31:22,700 --> 00:31:23,370 dinja. 684 00:31:23,370 --> 00:31:23,870 Hm. 685 00:31:23,870 --> 00:31:26,110 C'est tip ta 'bug. 686 00:31:26,110 --> 00:31:28,560 Probabbilment maħsuba biex ngħid Rob, id-dritt? 687 00:31:28,560 --> 00:31:30,997 Allura x'inhu l-jiffissaw hawn fil-kodiċi. 688 00:31:30,997 --> 00:31:31,872 STUDENT: [inaudible]. 689 00:31:31,872 --> 00:31:38,415 690 00:31:38,415 --> 00:31:39,290 DAVID Malan: Eżattament. 691 00:31:39,290 --> 00:31:43,160 So I biss ħtieġa li jagħmlu dak tweak finali hekk li jien tgħaddi fil placeholder, 692 00:31:43,160 --> 00:31:45,690 bħal imla l-vojt, bħal għamilna mument ilu. 693 00:31:45,690 --> 00:31:47,870 Imma fil-mija s issa huwa li timla l-vojt. 694 00:31:47,870 --> 00:31:52,100 Mela fl-aħħar ejja jiżvelaw wieħed aħħar dettall sabiex ma jkun hemm l-ebda magic. 695 00:31:52,100 --> 00:31:54,090 Jien ser jimxi 'l quddiem u jeħles hellow. 696 00:31:54,090 --> 00:31:56,070 Jien ser jimxi 'l quddiem u jeħles a.out. 697 00:31:56,070 --> 00:31:58,410 Allura issa I jkollhom ebda programmi, biss kodiċi sors tiegħi. 698 00:31:58,410 --> 00:32:01,100 U jien ser tmexxi kmand kemmxejn itwal, clang 699 00:32:01,100 --> 00:32:05,650 sing o bonjour LCS50 sing hello.c. 700 00:32:05,650 --> 00:32:08,700 >> Issa dan qed jibda tip ta 'jmorru fil-widna waħda u l-oħra forsi. 701 00:32:08,700 --> 00:32:10,366 Iżda biss tease apparti dak li dan qed tagħmel. 702 00:32:10,366 --> 00:32:14,910 Clang huwa l-kumpilatur, LCS50 sing deliberatament fl-aħħar nett 703 00:32:14,910 --> 00:32:18,330 ma dak fil-sentenza? 704 00:32:18,330 --> 00:32:19,607 Links għal-librerija CS50. 705 00:32:19,607 --> 00:32:21,440 Grabs l-żerijiet u dawk li l-persunal magħmula 706 00:32:21,440 --> 00:32:23,310 u crams minnhom fil-programm tiegħi stess. 707 00:32:23,310 --> 00:32:27,040 Allura l-aħħar mistoqsija fil-idejn huwa, dak li huwa sing o bonjour probabbilment 708 00:32:27,040 --> 00:32:30,530 tagħmel, anki jekk inti stajt qatt rajt dan sintassi qabel? 709 00:32:30,530 --> 00:32:34,920 >> Outputting programm li l- mhux imsemmi l-a.out default. 710 00:32:34,920 --> 00:32:37,330 Pjuttost huwa jismu bonjour. 711 00:32:37,330 --> 00:32:39,460 Allura issa m'hemm l-ebda a.out. 712 00:32:39,460 --> 00:32:42,660 Nru tali file jew direttorju, minħabba I qal espliċitament 713 00:32:42,660 --> 00:32:46,720 sejħa dan il-programm hello, b'tali mod li I issa tista tip fl-isem bħal dik 714 00:32:46,720 --> 00:32:47,790 u li hija jaġixxu. 715 00:32:47,790 --> 00:32:50,180 >> Issa franchement, boy huwa li uninteresting li jkollhom 716 00:32:50,180 --> 00:32:52,170 li tiftakar kollha ta 'dak ftit dettall, id-dritt? 717 00:32:52,170 --> 00:32:54,180 Mela ejja imorru quddiem u jeħles bonjour darb'oħra. 718 00:32:54,180 --> 00:32:57,880 U ejja issa jirritorna għal dinja fl li huwa biżżejjed li jingħad jagħmlu bonjour. 719 00:32:57,880 --> 00:33:00,410 Imma dak l-magic li jagħmlu qed tagħmel għalik, 720 00:33:00,410 --> 00:33:02,320 dak l-tedium li huwa qed jagħmel għalik. 721 00:33:02,320 --> 00:33:04,630 U kif il-programmi tagħna u problemi nikseb aktar kumplessi, 722 00:33:04,630 --> 00:33:06,142 jagħmlu se verament tkun ħabib tiegħek. 723 00:33:06,142 --> 00:33:07,850 Minħabba li mhux twil wisq minn issa aħna qed tmur 724 00:33:07,850 --> 00:33:11,150 li għandhom programmi li huma miktuba mhux ma wieħed fajl, iżda diversi fajls, 725 00:33:11,150 --> 00:33:16,310 u jagħmlu se awtomatizzat il-proċess ta ' kompilazzjoni kollha ta 'dik għalina flimkien. 726 00:33:16,310 --> 00:33:20,620 >> Allura issa print. 727 00:33:20,620 --> 00:33:24,960 printf huwa ġewwa ta 'dan il-fajl, standard I / O dot h, li aħna stajt tidher qabel, 728 00:33:24,960 --> 00:33:26,980 imma hemm aktar printf minn dak. 729 00:33:26,980 --> 00:33:30,482 Hemm n backslash, imma hemm ukoll mazz ta 'sekwenzi ħarba oħra. 730 00:33:30,482 --> 00:33:32,940 U s-sekwenza ta 'ħruġ huwiex biss mod fancy ta 'tgħid xi ħaġa 731 00:33:32,940 --> 00:33:35,990 li jibda bil backslash, mhux slash quddiem, backslash, 732 00:33:35,990 --> 00:33:37,920 u ma xi ħaġa speċjali. 733 00:33:37,920 --> 00:33:43,770 U aħna mhux se nitkellem fuq aktar ta 'dawn, iżda għaliex hemm backslash quote doppja, 734 00:33:43,770 --> 00:33:44,830 do you think? 735 00:33:44,830 --> 00:33:48,010 Għaliex hemm din is-sekwenza stramb ta karattri, kwotazzjoni doppja backslash, 736 00:33:48,010 --> 00:33:50,505 għaliex jista 'jkun li utli? 737 00:33:50,505 --> 00:33:51,380 STUDENT: [inaudible]. 738 00:33:51,380 --> 00:33:56,594 739 00:33:56,594 --> 00:33:57,760 DAVID Malan: Eżattament, id-dritt? 740 00:33:57,760 --> 00:34:01,830 Think lura għall-programm tagħna dinja bonjour li aħna stajt tidher pjuttost ftit drabi issa, 741 00:34:01,830 --> 00:34:05,880 kull darba li aħna stajt tidher f'dak dinja bonjour programm aħna kellna kwotazzjonijiet doppja ġewwa 742 00:34:05,880 --> 00:34:08,210 tagħhom huwa bonjour virgola dinja backslash n. 743 00:34:08,210 --> 00:34:10,070 Imma taħseb li inti stess, dak li jekk inti fil-fatt 744 00:34:10,070 --> 00:34:12,520 riedu jistampa mark kwotazzjoni? 745 00:34:12,520 --> 00:34:16,100 Ewwel istint tiegħek jista 'jkun, I ma know għaliex I tista 'tixtieq li do-- hawn, 746 00:34:16,100 --> 00:34:18,780 nistgħu nkunu passiva ftit aggressiva, bonjour ħabib. 747 00:34:18,780 --> 00:34:21,350 Aħna tista 'tixtieq li tagħmel xi ħaġa bħal dik. 748 00:34:21,350 --> 00:34:25,230 >> Iżda għaliex dan huwa issa problematika? 749 00:34:25,230 --> 00:34:28,730 Jinjora l-kwotazzjonijiet kaboċċi aside li ewlieni għamel għalina awtomatikament. 750 00:34:28,730 --> 00:34:29,730 Għaliex hija din il-problematika? 751 00:34:29,730 --> 00:34:36,719 752 00:34:36,719 --> 00:34:37,270 >> Eżattament. 753 00:34:37,270 --> 00:34:39,022 Għaliex għandna like 4 virgoletti. 754 00:34:39,022 --> 00:34:41,230 Ukoll l-ewwel waħda probabbilment tmur mat-tieni waħda, 755 00:34:41,230 --> 00:34:43,271 u forsi l-raba 'wieħed tmur mat-tielet wieħed, 756 00:34:43,271 --> 00:34:46,170 jew, I tfisser M'inix ċert anke, lanqas huwa l-kompjuter se tkun. 757 00:34:46,170 --> 00:34:48,352 Kompjuters għal darb'oħra, kompilaturi darb'oħra, huma pjuttost dumb. 758 00:34:48,352 --> 00:34:50,060 Huma ser biss tagħmel dak inti jgħidulhom li jagħmlu. 759 00:34:50,060 --> 00:34:54,270 U jekk int ma ambigwi huma huma probabbilment se tarmi żball. 760 00:34:54,270 --> 00:34:57,700 >> Jekk int ma ambigwi dwar kif tagħmel butir tal-karawett u sandwich jelly 761 00:34:57,700 --> 00:34:59,510 affarijiet strambi jista jaslu. 762 00:34:59,510 --> 00:35:00,580 Hu l-istess idea. 763 00:35:00,580 --> 00:35:03,100 Issa huwa biżżejjed li jingħad hemm xi sekwenzi oħra tal-salvataġġ, 764 00:35:03,100 --> 00:35:04,820 imma aħna ser jaslu għal dawk qabel twil. 765 00:35:04,820 --> 00:35:07,410 Essenzjalment dawn ħarba sekwenzi jirrappreżentaw xi ħaġa 766 00:35:07,410 --> 00:35:10,480 li inti tista 'ma tkun kapaċi wisq faċilment fil-keyboard, 767 00:35:10,480 --> 00:35:12,010 mingħajr ma jikkonfondi l-kompjuter. 768 00:35:12,010 --> 00:35:15,733 >> Issa sadanittant għandna placeholders fil printf. 769 00:35:15,733 --> 00:35:19,630 Perċentwali d, li jistgħu wkoll jiġu miktuba kważi fil-każijiet kollha bħala mija i, 770 00:35:19,630 --> 00:35:21,610 huwa placeholder għal liema tip ta 'data? 771 00:35:21,610 --> 00:35:23,920 Liema tip ta 'valur? 772 00:35:23,920 --> 00:35:24,920 A numru deċimali. 773 00:35:24,920 --> 00:35:27,234 Allura fil-fatt aħna ser tibda użu fil-mija i għaliex dan huwa 774 00:35:27,234 --> 00:35:28,650 ftit aktar sempliċi, bħal integer. 775 00:35:28,650 --> 00:35:29,550 I Perċentwali. 776 00:35:29,550 --> 00:35:31,320 Integer li jiġri li jkun deċimali. 777 00:35:31,320 --> 00:35:35,690 >> Perċentwali s aħna diġà qal ma kien placeholder għal string. 778 00:35:35,690 --> 00:35:38,630 Liema hija biss kelma, frażi, paragrafu, esej, ikun x'ikun. 779 00:35:38,630 --> 00:35:40,830 Huwa sekwenza ta ' karattri ta 'tul. 780 00:35:40,830 --> 00:35:42,820 U aħna ser tara qabel twil xi wħud minn dawn ħaddieħor. 781 00:35:42,820 --> 00:35:45,950 Iżda fil-mija c hija għal karattru wieħed. 782 00:35:45,950 --> 00:35:48,500 Perċentwali f hija għal punt numru galleġġjanti, 783 00:35:48,500 --> 00:35:50,860 bħal numru reali li għandha punt deċimali fiha, li 784 00:35:50,860 --> 00:35:52,550 huwa ta 'kors mhux numru sħiħ. 785 00:35:52,550 --> 00:35:54,670 U hemm kollu mazz ta 'oħrajn ukoll. 786 00:35:54,670 --> 00:35:56,990 >> Sadanittant fis-C, u fil-lott ta 'lingwi, 787 00:35:56,990 --> 00:35:58,650 għandna tipi differenti ta 'dejta. 788 00:35:58,650 --> 00:36:00,650 Tipi differenti ta ' ħġieġ skutelli jekk inti se. 789 00:36:00,650 --> 00:36:03,830 Il-bowl I użat aħħar darba kien għal blalen ping pong, 790 00:36:03,830 --> 00:36:06,990 iżda nistgħu wkoll jaħżnu differenti Valuri bħal Chars u kordi 791 00:36:06,990 --> 00:36:10,820 u interi f'kontenitur, bħal varjabbli, u C għandu dawn. 792 00:36:10,820 --> 00:36:14,020 Char huwa t-tip ta 'data, it-tip ta 'varjabbli, 793 00:36:14,020 --> 00:36:15,700 fejn inti jista 'jaħżen karattru. 794 00:36:15,700 --> 00:36:19,560 Float huwa tip ta 'varjabbli fl li inti jista 'jaħżen numru reali. 795 00:36:19,560 --> 00:36:21,220 >> Int huwa ta 'kors għal int. 796 00:36:21,220 --> 00:36:23,760 U pjuttost ridiculously jismu twil twil 797 00:36:23,760 --> 00:36:26,830 huwa fejn inti jista 'jaħżen essenzjalment numru verament twila, anke ma 798 00:36:26,830 --> 00:36:29,930 aktar ċifri imbagħad Jista maħżen int tipiku. 799 00:36:29,930 --> 00:36:32,420 Iżda aħna ser terga 'lura għal li qabel twil. 800 00:36:32,420 --> 00:36:35,520 >> Fil CS50 dot h sadanittant il-fajl header oħra 801 00:36:35,520 --> 00:36:37,630 li aħna stajt tidher koppja darbiet użu, hemm 802 00:36:37,630 --> 00:36:41,350 żewġ tipi ta 'data oħra li ma jeżistux fis-C tipikament. 803 00:36:41,350 --> 00:36:45,000 Wieħed huwa string, u aħna ser tara fil ftit ġimgħat liema kordi verament 804 00:36:45,000 --> 00:36:46,610 huma taħt il-barnuża. 805 00:36:46,610 --> 00:36:47,950 U waħda hija bool. 806 00:36:47,950 --> 00:36:51,650 U bool hija varjabbli li jista 'jieħu biss fuq ċerti valuri. 807 00:36:51,650 --> 00:36:54,370 U biss ibbażata fuq ġimgħa li għaddiet spjegazzjoni ta 'Scratch, 808 00:36:54,370 --> 00:36:56,680 u aktar reċentement C, dak li għandek raden 809 00:36:56,680 --> 00:37:01,770 huma ż-żewġ valuri possibbli għall xi kontenitur li ma tkunx tat bool tip? 810 00:37:01,770 --> 00:37:02,860 >> Iva u le. 811 00:37:02,860 --> 00:37:03,870 Wieħed u żero. 812 00:37:03,870 --> 00:37:04,502 Veru jew falz. 813 00:37:04,502 --> 00:37:07,460 U fil-fatt huwa l-aħħar li għandha tendenza li jkun konvenzjonali fil-programmazzjoni 814 00:37:07,460 --> 00:37:10,030 lingwa, tgħid xi ħaġa bħall vera jew falza. 815 00:37:10,030 --> 00:37:13,160 >> Sadanittant il-librerija CS50 ġejja bil-mazz ta 'funzjonalità 816 00:37:13,160 --> 00:37:16,640 li l-persunal kiteb għalik, minbarra biss jkollna string. 817 00:37:16,640 --> 00:37:20,910 Aħna kiteb fil-funzjonijiet bil-quddiem li jistgħu jiksbu integer mill-utent, 818 00:37:20,910 --> 00:37:22,990 tikseb karattru wieħed, jiksbu float, li 819 00:37:22,990 --> 00:37:25,160 huwa biss numru mal-punt deċimali. 820 00:37:25,160 --> 00:37:28,290 Get a twil twil, verament valur big mill-utent. 821 00:37:28,290 --> 00:37:30,930 Allura aħna ve biss dehru dan fil azzjoni fil-forma ta 'GetString. 822 00:37:30,930 --> 00:37:33,230 Iżda permezz ta 'dawn il-funzjonijiet dalwaqt se tkun tista 'tikteb 823 00:37:33,230 --> 00:37:36,070 programmi li tikseb input mill-utent. 824 00:37:36,070 --> 00:37:39,230 >> Sadanittant jikkunsidraw dan programm, u jikkunsidraw 825 00:37:39,230 --> 00:37:42,600 kif aħna issa tista 'tibda biex iżżid lilha bl constructs ġodda. 826 00:37:42,600 --> 00:37:44,530 A tour whirlwind quick u allura aħna ser tħares 827 00:37:44,530 --> 00:37:47,340 f'xi kitba f'xi programmi manwalment nfusna. 828 00:37:47,340 --> 00:37:49,700 Minn issa jekk irridu li timplimenta kundizzjoni, 829 00:37:49,700 --> 00:37:52,790 mhuwiex ser look like a sbieħ ftit biċċa puzzle pretty. 830 00:37:52,790 --> 00:37:54,460 Huwa ser tħares ftit aktar arcane. 831 00:37:54,460 --> 00:37:57,620 Iżda dan huwa l-canonical istruttura ta 'kondizzjoni fil C. 832 00:37:57,620 --> 00:38:00,380 >> Il-kelma jekk, tnejn parentesi, ġewwa li minnhom 833 00:38:00,380 --> 00:38:02,590 se jkun hemm xi tip ta 'espressjoni Boolean. 834 00:38:02,590 --> 00:38:04,999 Issa l-slash slash fin-nofs, dan huwa 835 00:38:04,999 --> 00:38:07,290 fil-mument tip simili kodiċi placeholder pseudocode. 836 00:38:07,290 --> 00:38:11,576 Iżda aktar kif suppost, kwalunkwe linja tal-kodiċi fis-C li tibda bi slash slash 837 00:38:11,576 --> 00:38:12,850 huwa kumment. 838 00:38:12,850 --> 00:38:15,920 >> Huwa simili nota twaħħal li inti tista jitqiegħdu fuq esej, stampata fuq karta. 839 00:38:15,920 --> 00:38:17,290 Huwa nota lill yourself. 840 00:38:17,290 --> 00:38:20,100 Hija għandha l-ebda funzjonali impatt fuq il-programm. 841 00:38:20,100 --> 00:38:23,580 Huwa tip ta 'tfakkira, huwa tiegħek stess dokumentazzjoni dwar x'inhu għaddej. 842 00:38:23,580 --> 00:38:25,720 Allura tagħmel dan fil-mument huwa tip ta 'placeholder 843 00:38:25,720 --> 00:38:27,560 għal kwalunkwe huwa ġewwa ta 'dawk ċingi kaboċċi 844 00:38:27,560 --> 00:38:29,810 eventwalment se jagħmlu xi ħaġa. 845 00:38:29,810 --> 00:38:35,160 >> Sadanittant għandek żewġ frieket fl- triq, li jekk inkella jinbena bħal dan. 846 00:38:35,160 --> 00:38:37,024 Inti tista 'jekk, ElseIf, inkella. 847 00:38:37,024 --> 00:38:39,690 Issa huwa min jinnota, speċjalment jekk inti kont qed Googling madwar 848 00:38:39,690 --> 00:38:42,480 online għar-riżorsi minn kurżità, jew jekk inti pick up 849 00:38:42,480 --> 00:38:44,575 wieħed mill-l-kors kotba rakkomandati fuq C, 850 00:38:44,575 --> 00:38:48,430 se tara li l-bnedmin jkollhom lottijiet preferenzi ta differenti għall kif 851 00:38:48,430 --> 00:38:50,510 biex jesprimu ruħhom fil-kodiċi. 852 00:38:50,510 --> 00:38:53,800 Xi nies jixtiequ li jpoġġu l- braces kaboċċi bħala I ghamilt hawn. 853 00:38:53,800 --> 00:38:57,760 Xi nies jixtiequ li jpoġġu l-kaboċċi ċingi per eżempju up here. 854 00:38:57,760 --> 00:39:01,700 >> Xi nies jixtiequ li jpoġġu l-elses up hawn u allura dan hawn fuq. 855 00:39:01,700 --> 00:39:05,120 Hemm xi numru ta 'modi biex jikteb il-kodiċi, u ħadd minnhom 856 00:39:05,120 --> 00:39:06,566 huma dritt per se. 857 00:39:06,566 --> 00:39:08,440 Għalkemm hemm ftit li huma pjuttost ħażin. 858 00:39:08,440 --> 00:39:11,315 Iżda hemm no-- jekk dan huwa finalment dibattitu reliġjużi ħafna. 859 00:39:11,315 --> 00:39:13,940 Fil-fatt, wieħed mill-aktar annoying affarijiet dwar ix-xjenza tal-kompjuter 860 00:39:13,940 --> 00:39:16,310 huwa kif opinionated xjenzjati tal-kompjuter jista 'jkun. 861 00:39:16,310 --> 00:39:19,880 U inti ser issib matul iż-żmien li anke inti tiżviluppa l-preferenzi personali 862 00:39:19,880 --> 00:39:22,130 kif kodiċi tiegħek għandha tfittex. 863 00:39:22,130 --> 00:39:27,162 >> Mhux biss iġibu ruħhom, mhux biss joħolqu l-output, imma kif hu għandu jeżamina estetikament. 864 00:39:27,162 --> 00:39:30,120 Allura dak li aħna se nagħmlu huwa jiggwidaw inti tul it-triq lejn, għal issa mill-inqas, 865 00:39:30,120 --> 00:39:34,825 stil CS50 standard li mill-inqas żżomm affarijiet uniformi u faċli biex jinqara. 866 00:39:34,825 --> 00:39:37,330 Iżda aktar fuq dawk distinzjonijiet qabel twil. 867 00:39:37,330 --> 00:39:41,830 >> A espressjoni Boolean fis-C, jekk inti riedu jgħidu jekk din il-kundizzjoni hija vera 868 00:39:41,830 --> 00:39:44,650 u din il-kundizzjoni l-oħra hija veru, inti ma jiktbu l-kelma 869 00:39:44,650 --> 00:39:46,610 u, kif inti fil-Ingliż. 870 00:39:46,610 --> 00:39:50,580 Inti minflok tuża ampersand ampersand, għal raġunijiet aħna ser terga 'lura għal. 871 00:39:50,580 --> 00:39:54,520 Jekk inti tixtieq li tgħid jew tuża tnejn bars vertikali, li fuq tastiera Istati Uniti 872 00:39:54,520 --> 00:39:57,650 hija ġeneralment ogħla mill-Ikteb jmiss muftieħ għall-backslash. 873 00:39:57,650 --> 00:40:03,080 U dan ifisser biss jekk din il-kundizzjoni jew din il-kundizzjoni l-oħra hija veru tagħmel dan. 874 00:40:03,080 --> 00:40:05,210 >> Sadanittant hemm dan ħaġa crazy, li 875 00:40:05,210 --> 00:40:07,760 inti ser ikollok okkażjoni li tuża darba awhile. 876 00:40:07,760 --> 00:40:10,390 Iżda huwa biss alternattiva mod biex tesprimi ruħek. 877 00:40:10,390 --> 00:40:12,400 Dan, għal issa, ejja jistipula, huwa biss 878 00:40:12,400 --> 00:40:16,880 mod ieħor funky li jesprimu jekk, ElseIf, ElseIf, ElseIf, ElseIf. 879 00:40:16,880 --> 00:40:19,720 Huwa biss formattjati f'termini ta 'każijiet, fejn inti litteralment 880 00:40:19,720 --> 00:40:23,420 tenumera l-valuri li inti tista 'tixtieq li jiċċekkjaw għall. 881 00:40:23,420 --> 00:40:24,410 >> Sadanittant loops. 882 00:40:24,410 --> 00:40:26,842 Rajna paragun ta ' Scratch ma 'loop. 883 00:40:26,842 --> 00:40:29,550 U jien ser mewġa naħa tiegħi fil liema kull waħda minn dawn l-affarijiet jfisser. 884 00:40:29,550 --> 00:40:33,520 Iżda tinnota li loop se ħafna spiss tibda bil-keyword għall. 885 00:40:33,520 --> 00:40:36,350 Jew se tibda bil-keyword waqt. 886 00:40:36,350 --> 00:40:41,360 Jew se tibda bil-keyword do, u jintemm bit-keyword waqt. 887 00:40:41,360 --> 00:40:43,920 >> Imma dak li aħna qed waslu biex tara hija aktar affarijiet bħal dan. 888 00:40:43,920 --> 00:40:47,950 Hawnhekk huwa, b'mod ġenerali fis-C, kif inti tista ' tiddikjara varjabbli u tagħtiha valur. 889 00:40:47,950 --> 00:40:50,610 Fil C mhuwiex suffiċjenti, bħal fil Scratch, inti biss 890 00:40:50,610 --> 00:40:52,810 jgħidu tagħti me a varjabbli msejħa xi ħaġa. 891 00:40:52,810 --> 00:40:55,960 Int għandek tgħid C, u għid kompilatur tiegħek, b'mod aktar speċifiku, 892 00:40:55,960 --> 00:40:58,680 liema tip ta 'valur do inti tixtieq li tqiegħed fl-iskutella tal-ħġieġ. 893 00:40:58,680 --> 00:40:59,610 >> Huwa integer? 894 00:40:59,610 --> 00:41:02,210 Jekk iva, inti għandek litteralment jgħidu int u mbagħad 895 00:41:02,210 --> 00:41:04,220 l-isem tal-varjabbli, imbagħad virgola. 896 00:41:04,220 --> 00:41:08,050 Jekk inti minflok riedu string u sejjaħ hija s bħal I ma kodiċi tiegħi hawn illum, 897 00:41:08,050 --> 00:41:10,920 inti ngħid string s virgola. 898 00:41:10,920 --> 00:41:14,200 Ladarba inti tixtieq li tagħtiha valur inti tista 'mbagħad jużaw is-sinjal ugwali, 899 00:41:14,200 --> 00:41:16,211 inkella magħruf bħala l- operatur assenjazzjoni. 900 00:41:16,211 --> 00:41:17,960 U avviż kif kull ta 'dawn il-linji ta' kodiċi 901 00:41:17,960 --> 00:41:20,650 għandha l-virgola fi tmiem ta 'dan. 902 00:41:20,650 --> 00:41:22,550 >> Iżda franchement dan biss jistenna ftit ikrah. 903 00:41:22,550 --> 00:41:26,580 Għaliex ma nista 'ngħid għall-kompjuter, jagħtu me varjabbli u initialize fuq żero. 904 00:41:26,580 --> 00:41:28,380 Jiġifieri, tagħti me skutella ħġieġ vojta. 905 00:41:28,380 --> 00:41:28,980 Filwaqt li inti tista '. 906 00:41:28,980 --> 00:41:32,250 U għalhekk wieħed tas-sentenza iċempillek taf għandek tagħmel stylistically matul iż-żmien 907 00:41:32,250 --> 00:41:36,290 huwa, do tikteb kodiċi tiegħek bħal dan, jew do you tip ta 'inaddfu up u tagħfas 908 00:41:36,290 --> 00:41:39,040 nies bil-kitba żewġ linji biss bħala wieħed. 909 00:41:39,040 --> 00:41:41,830 U dan jitqies ġeneralment b'mod aktar eleganti 910 00:41:41,830 --> 00:41:43,870 tal-kitba kodiċi tiegħek stylistically. 911 00:41:43,870 --> 00:41:45,200 >> Funzjonijiet aħna qed ovvjament tidher. 912 00:41:45,200 --> 00:41:46,340 Huma qed tmur biex tieħu dan il-format. 913 00:41:46,340 --> 00:41:48,881 L-isem ta 'funzjoni, xi parentesi, u mbagħad forsi xi 914 00:41:48,881 --> 00:41:49,910 Jittieħed ġewwa. 915 00:41:49,910 --> 00:41:52,540 Jew inti tista 'tara l-użi ta' funzjonijiet multipli ġenb 916 00:41:52,540 --> 00:41:55,980 ġenb, bħal xi ħaġa bħal din. 917 00:41:55,980 --> 00:41:59,390 Issa bħala tanġent, ma dan Joke issa jagħmel sens? 918 00:41:59,390 --> 00:42:03,566 919 00:42:03,566 --> 00:42:04,960 >> [Rires] 920 00:42:04,960 --> 00:42:09,360 Dan ma jfissirx huwa umoristiċi, iżda ma forsi jagħmlu ftit aktar sens. 921 00:42:09,360 --> 00:42:12,140 Allura issa ejja jmorru fil- Appliance CS50 għal mument. 922 00:42:12,140 --> 00:42:14,640 U let me jiftħu teaser wieħed hawn. 923 00:42:14,640 --> 00:42:17,470 >> U fil-fatt waħda mir-raġunijiet għall-introduzzjoni katalogu IKEA 924 00:42:17,470 --> 00:42:20,080 u teptip l-istampa tal-iPhone daqsxejn ilu 925 00:42:20,080 --> 00:42:24,700 kien li attwalment jorbtu flimkien l- fatt li biss ftit snin ilu, fl-2007, 926 00:42:24,700 --> 00:42:26,540 din il-biċċa tal-kodiċi kien rilaxxati, li kienet 927 00:42:26,540 --> 00:42:29,820 wieħed mill-ewwel implimentazzjoni ta 'biċċa ta' softwer 928 00:42:29,820 --> 00:42:31,494 li ma dak li sejjaħ jailbreaking. 929 00:42:31,494 --> 00:42:34,410 Għal dawk familjari, jailbreaking xi ħaġa bħal telefon jew iPhone 930 00:42:34,410 --> 00:42:37,680 ifisser essenzjalment jidhru kif jagħmlu l-affarijiet 931 00:42:37,680 --> 00:42:39,864 magħha li l-kumpanija li għamilha ma riditx. 932 00:42:39,864 --> 00:42:42,780 Bħal inti tixtieq li tinstalla ċerti software li mhux fil-maħżen app, 933 00:42:42,780 --> 00:42:45,405 jailbreaking phone tiegħek li inti tagħmel affarijiet bħal dik u aktar. 934 00:42:45,405 --> 00:42:47,447 Imma dak li kien gost fil 2007-- u hemm kien 935 00:42:47,447 --> 00:42:49,780 għexieren ta 'verżjonijiet differenti ta 'dawn l-affarijiet minn dakinhar, 936 00:42:49,780 --> 00:42:53,540 kull xorta ta 'languages-- hija li dan il-programm hawn, imsejħa iUnlock, 937 00:42:53,540 --> 00:42:57,036 kienet attwalment miktuba C. U hekk I jinġibed up-source code għal dan, 938 00:42:57,036 --> 00:42:59,910 biss biex tip ta 'turi li inti xi wħud l-similaritajiet mal-constructs 939 00:42:59,910 --> 00:43:01,450 konna qed tiddiskuti s'issa. 940 00:43:01,450 --> 00:43:05,150 Issa hemm mod aktar kumplessità hawn milli Rajna diġà fil-klassi. 941 00:43:05,150 --> 00:43:07,160 Let me iscroll up biss ftit hawn. 942 00:43:07,160 --> 00:43:11,520 >> Iżda avviż these-- ukoll aħna Avviż xi ftit things-- iżda tinnota dawn il-linji hawnhekk, 943 00:43:11,520 --> 00:43:14,090 inklużi standard I / O dot h. 944 00:43:14,090 --> 00:43:17,660 U all-- linja 24, please-- Avviż I standard / O 945 00:43:17,660 --> 00:43:21,380 dot h u mazz sħiħ ta 'l-oħra fajls li nies apparentement oħra 946 00:43:21,380 --> 00:43:22,160 kitbu. 947 00:43:22,160 --> 00:43:24,850 U jekk aħna iscroll permezz dan, ftit arbitrarju, 948 00:43:24,850 --> 00:43:27,910 Avviż I do not know kif jiktbu kollha ta 'dan myself neċessarjament għadhom, 949 00:43:27,910 --> 00:43:28,880 iżda hemm jekk. 950 00:43:28,880 --> 00:43:30,400 Allura apparentement dan jkollha fergħa. 951 00:43:30,400 --> 00:43:33,210 >> U jekk I iscroll ftit ulterjuri hemm ieħor jekk. 952 00:43:33,210 --> 00:43:38,210 Jekk I iscroll up, I think madwar linja 100 I raw għal. 953 00:43:38,210 --> 00:43:40,020 So jien ma pjuttost ċert kif taħdem din għadha, 954 00:43:40,020 --> 00:43:43,180 iżda dan huwa għal loop li għaddej biex let me jtenni xi numru ta 'drabi. 955 00:43:43,180 --> 00:43:45,230 U jekk I iscroll kollha il-mod lejn il-qiegħ 956 00:43:45,230 --> 00:43:51,020 Nara li hemm jiffunzjonaw stabbiliti hawn jissejjaħ 957 00:43:51,020 --> 00:43:54,570 prinċipali, u xi krediti addizzjonali għall-pjaċir qari tiegħek. 958 00:43:54,570 --> 00:43:57,830 >> Allura dan huwa biss biex say-- u aħna ser jitqiegħdu dan online fost sors fil-kors tal- 959 00:43:57,830 --> 00:44:01,480 kodiċi today-- li anki xi wħud minn dawn apparati li nieħdu għall mogħtija, 960 00:44:01,480 --> 00:44:05,130 fl-aħħar tal-ġurnata int xorta jużaw dawn constructs bażiċi li konna 961 00:44:05,130 --> 00:44:07,430 kienu jintroduċu diġà s'issa. 962 00:44:07,430 --> 00:44:08,620 C'est biżżejjed ta 'li wieħed. 963 00:44:08,620 --> 00:44:11,480 Kull dritt, hekk issa ejja attwalment jibnu xi ħaġa. 964 00:44:11,480 --> 00:44:15,640 >> Ejja ħa mmorru lil hinn xi ħaġa simili hello.c, u jiftħu dan, 965 00:44:15,640 --> 00:44:17,170 ejja tikteb dan il-programm hawn. 966 00:44:17,170 --> 00:44:19,850 Jien ser jimxi 'l quddiem u jiktbu program imsejjaħ adder.c, 967 00:44:19,850 --> 00:44:23,310 iskop tagħhom fil-ħajja se tkun bħall-ewwel calculator sempliċi super tiegħi 968 00:44:23,310 --> 00:44:24,840 li żżid biss ftit ta 'numri. 969 00:44:24,840 --> 00:44:27,050 Mhux għaliex thats iebsa problema, iżda minħabba li 970 00:44:27,050 --> 00:44:29,390 tippermetti lili biex issa torbot flimkien ftit affarijiet. 971 00:44:29,390 --> 00:44:33,100 So jien ser jimxi 'l quddiem u jinkludu I standard / O dot h u CS50 dot h. 972 00:44:33,100 --> 00:44:34,670 Jien se ngħid null prinċipali int. 973 00:44:34,670 --> 00:44:36,545 U għal darb'oħra fil-futur aħna ser terga 'lura għal 974 00:44:36,545 --> 00:44:38,560 fis f'dan il-kuntest u l-mezzi null. 975 00:44:38,560 --> 00:44:43,340 >> U issa jien se ngħid xi ħaġa bħal printf, tagħti me integer. 976 00:44:43,340 --> 00:44:47,610 U issa fuq tieni linja tiegħi, kif nista nesprimi ruħi bħal 977 00:44:47,610 --> 00:44:50,980 li nixtieq li tiddikjara varjabbli li għaddej biex jaħżnu int? 978 00:44:50,980 --> 00:44:55,470 Litteralment liema do I tip jekk irrid li joħolqu varjabbli li taħżen l-int 979 00:44:55,470 --> 00:44:58,270 would you say? 980 00:44:58,270 --> 00:44:59,650 int a ugwali getint. 981 00:44:59,650 --> 00:45:00,485 Sure, hekk li x-xogħlijiet. 982 00:45:00,485 --> 00:45:02,360 U biss għall-konsistenza mal-kodiċi tkun taf 983 00:45:02,360 --> 00:45:04,485 tara online, let me bidla dan x, biss minħabba x 984 00:45:04,485 --> 00:45:06,830 huwa isem varjabbli komuni għall-użu, għall-inqas fl-alġebra. 985 00:45:06,830 --> 00:45:08,720 Issa let me imorru quddiem u ma printf darb'oħra. 986 00:45:08,720 --> 00:45:10,692 Agħti me numru sħiħ ieħor. 987 00:45:10,692 --> 00:45:12,900 U issa jien se tip ta jitgħallmu minn dak il-mudell, 988 00:45:12,900 --> 00:45:14,490 Jien se ngħid y int gets GetInt. 989 00:45:14,490 --> 00:45:16,340 >> U aħna ħadthom ma jintużax GetInt qabel, iżda biss 990 00:45:16,340 --> 00:45:19,860 bħall GetString tmur u gets string, bħal Javier għamlet mill-udjenza, 991 00:45:19,860 --> 00:45:22,780 Bl-istess mod ma GetInt tibda Teptip fil-pront. 992 00:45:22,780 --> 00:45:26,750 U effettivament stennija għall-utent li tagħtiha integer, billi jittajpja fil 993 00:45:26,750 --> 00:45:27,900 u laqtu Ikteb. 994 00:45:27,900 --> 00:45:30,850 Issa fl-aħħar jien ser tagħmel dan, printf-somma of-- 995 00:45:30,850 --> 00:45:36,080 u let me nikseb now-- fancy mija iu fil-mija i huwa preżenti 996 00:45:36,080 --> 00:45:39,270 i exclamation punt backslash n. 997 00:45:39,270 --> 00:45:42,750 U x'taħseb li jien ser jitqiegħdu fil issa bħala l-inputs addizzjonali 998 00:45:42,750 --> 00:45:44,620 li printf? 999 00:45:44,620 --> 00:45:47,380 >> Ma rridx ngħid litteralment nikkwota unquote x. 1000 00:45:47,380 --> 00:45:52,210 Irrid li klassi xu imbagħad, u issa ejja nikseb fancy 1001 00:45:52,210 --> 00:45:54,420 u ejja biss wieħed jassumi nistgħu nagħmlu dak li rridu. 1002 00:45:54,420 --> 00:45:56,330 Dak li inti trid tgħid li jmiss? 1003 00:45:56,330 --> 00:45:57,070 x plus y. 1004 00:45:57,070 --> 00:45:58,520 U fil-fatt li se jaħdmu. 1005 00:45:58,520 --> 00:46:01,760 Huwa minimament lingwi ta 'programmar do jifhmu aritmetika bażiku, 1006 00:46:01,760 --> 00:46:03,500 u għalhekk dan għandu fil-fatt ix-xogħol. 1007 00:46:03,500 --> 00:46:06,730 >> So let me imorru quddiem u ma jagħmlu Aġent li jżid fil-tieqa iswed u abjad tiegħi 1008 00:46:06,730 --> 00:46:08,090 stabbiliti hawn, Ikteb. 1009 00:46:08,090 --> 00:46:10,830 Linja cryptic iżda l-ebda żball messaġġ, hekk li tajjeb. 1010 00:46:10,830 --> 00:46:14,410 Dot mmejla aġent li jżid, tagħti me integer, 1. 1011 00:46:14,410 --> 00:46:16,230 Agħti me numru sħiħ ieħor, 2. 1012 00:46:16,230 --> 00:46:18,770 Is-somma ta '1 u 2 hija 3. 1013 00:46:18,770 --> 00:46:21,730 >> Kull dritt, so a pretty trivjali programm, imma x'hemm dan isir? 1014 00:46:21,730 --> 00:46:25,680 Huwa permess me biex jużaw funzjoni sejħa hawn, sejħa funzjoni oħra hawn, 1015 00:46:25,680 --> 00:46:29,260 żewġ sejħiet għal GetInt, għal sejħa terz sabiex printf, 1016 00:46:29,260 --> 00:46:30,720 u mbagħad jużaw dawn placeholders. 1017 00:46:30,720 --> 00:46:33,160 Allura huwa ftit aktar sofistikata minn aħħar darba. 1018 00:46:33,160 --> 00:46:35,260 Imma x'jiġri jekk irrid jiksbu ftit fancier? 1019 00:46:35,260 --> 00:46:38,900 >> Let me imorru quddiem u issa jagħmlu dan. 1020 00:46:38,900 --> 00:46:42,890 Let me imorru quddiem u joħolqu fajl ġdid imsejjaħ kondizzjonijiet żero. 1021 00:46:42,890 --> 00:46:44,890 U jien ser tiffranka xi żmien għall-klassijiet fini 1022 00:46:44,890 --> 00:46:48,260 u biss paste f'dik kodiċi bħala punt tat-tluq. 1023 00:46:48,260 --> 00:46:51,510 U issa jien biss ser jitqiegħdu xi ħaġa ġdida hawn fin-nofs. 1024 00:46:51,510 --> 00:46:55,889 So printf Nixtieq integer jekk jogħġbok. 1025 00:46:55,889 --> 00:46:58,180 U dan kollu kodiċi huwa disponibbli fuq il-websajt tal-kors, il- 1026 00:46:58,180 --> 00:47:00,556 inti għandek bżonn ma tip dan kollu fil-klassi jekk youd pjuttost ma. 1027 00:47:00,556 --> 00:47:02,638 int, u issa jien ser użu, minflok ta 'X u Y, 1028 00:47:02,638 --> 00:47:05,270 Jien ser tuża n, li hija probabbilment l-isem aktar komuni 1029 00:47:05,270 --> 00:47:09,220 għal integer fi programm tal-kompjuter. 1030 00:47:09,220 --> 00:47:12,060 U issa nixtieq li tagħmel ftit sentenza hawn. 1031 00:47:12,060 --> 00:47:15,460 Jien ser tara jekk n huwa akbar minn 0, allura 1032 00:47:15,460 --> 00:47:23,670 Jien se ngħid Whoops printf--, printf-- inti qabad numru pożittiv, 1033 00:47:23,670 --> 00:47:25,370 exclamation punt backslash n. 1034 00:47:25,370 --> 00:47:26,460 Agħlaq dik. 1035 00:47:26,460 --> 00:47:33,150 Else Jien ser jistampa printf inti qabad numru negattiv. 1036 00:47:33,150 --> 00:47:35,377 >> Issa qabel ma inti Yell fil lili, ejja run dan il-programm. 1037 00:47:35,377 --> 00:47:36,210 Let me jinżlu hawn. 1038 00:47:36,210 --> 00:47:40,730 U kif nista jikkompilaw programm kundizzjonijiet imsejħa sing 0? 1039 00:47:40,730 --> 00:47:42,300 Jagħmlu kundizzjonijiet sing 0. 1040 00:47:42,300 --> 00:47:45,560 Tip ta 'isem stupid, but-- dammit. 1041 00:47:45,560 --> 00:47:47,560 OK, mument tagħlim tajba. 1042 00:47:47,560 --> 00:47:48,410 Għaliex ma li jiksru? 1043 00:47:48,410 --> 00:47:51,360 1044 00:47:51,360 --> 00:47:54,710 >> What did I aċċidentalment call dan il-fajl? 1045 00:47:54,710 --> 00:47:56,876 Tista 'tip ta' jiddeduċi mill-tab up here. 1046 00:47:56,876 --> 00:47:58,750 Allura huwa mhux ħażin li jien ma dan, għaliex dan 1047 00:47:58,750 --> 00:48:00,208 se jiġri forsi biex xi wħud minnkom. 1048 00:48:00,208 --> 00:48:03,880 So I aċċidentalment jismu tiegħi sors kundizzjoni kodiċi 0. 1049 00:48:03,880 --> 00:48:09,950 Iżda kodiċi sors tiegħi permezz tal-konvenzjoni għandhom tkun fajl imsejjaħ kundizzjoni 0 sing c, 1050 00:48:09,950 --> 00:48:11,720 jew kwalunkwe dot c. 1051 00:48:11,720 --> 00:48:12,610 >> So let me jiffissaw dan. 1052 00:48:12,610 --> 00:48:16,880 Eżatt bħal Microsoft Word I tista 'tmur up biex Save As u tagħmel kundizzjoni 0 dot c. 1053 00:48:16,880 --> 00:48:20,100 Issa biss sabiex ikunu imbarazz jien se jmorru 'l quddiem u neħħi 1054 00:48:20,100 --> 00:48:23,020 kundizzjoni 0, li kien verżjoni l-qadima tiegħi. 1055 00:48:23,020 --> 00:48:26,550 U issa ejja do jagħmlu kundizzjoni 0, Ikteb. 1056 00:48:26,550 --> 00:48:27,870 OK, jidher tajjeb. 1057 00:48:27,870 --> 00:48:29,510 >> Kundizzjoni 0, Ikteb. 1058 00:48:29,510 --> 00:48:33,530 Nixtieq integer jogħġbok, 50, inti qabad numru pożittiv. 1059 00:48:33,530 --> 00:48:35,390 Issa kif madwar negattiva 50? 1060 00:48:35,390 --> 00:48:37,660 Inti qabad numru negattiv. 1061 00:48:37,660 --> 00:48:39,605 Kif dwar issa, 0. 1062 00:48:39,605 --> 00:48:42,250 1063 00:48:42,250 --> 00:48:45,350 Pretty żgur 0 mhuwiex negattiv. 1064 00:48:45,350 --> 00:48:47,780 >> Allura dan huwa tip ta 'bug loġiku. 1065 00:48:47,780 --> 00:48:50,680 Kif nista jiffissaw dan? 1066 00:48:50,680 --> 00:48:57,260 Else jekk n hija inqas minn 0, jagħmlu dan, inkella jista 'jkollna tliet mod fergħa hawn, 1067 00:48:57,260 --> 00:49:01,740 printf inti qabad 0. 1068 00:49:01,740 --> 00:49:06,150 Allura issa jekk I terġa 'ssir din programm, wara jikkompilawh 1069 00:49:06,150 --> 00:49:10,790 mill-ġdid ma tagħmel, u issa terġa 'ssir kundizzjoni 0, dak I ser tara hawn 1070 00:49:10,790 --> 00:49:14,570 hija ta '0 tagħti me dak output. 1071 00:49:14,570 --> 00:49:16,280 Għalhekk, fejn huma aħna jmorru ma 'dan? 1072 00:49:16,280 --> 00:49:18,930 >> Ukoll huwa faċli ħafna li jitilfu vista tal-foresti, għas-siġar. 1073 00:49:18,930 --> 00:49:23,590 U hekk inessu li jikkonkludu ma dan il-video 2 u 1/2 minuta 1074 00:49:23,590 --> 00:49:25,710 li finalment huwa daqsxejn ta 'ad mill-Google, 1075 00:49:25,710 --> 00:49:28,850 imma li verament huwa xhieda li liema anke jużaw dawn bini bażika 1076 00:49:28,850 --> 00:49:33,020 blokki aħna finalment tista 'tagħmel darba għandna daqsxejn ta 'programmar 1077 00:49:33,020 --> 00:49:34,463 sofistikati taħt ċinturini tagħna. 1078 00:49:34,463 --> 00:49:35,150 >> [Daqq ta mużika] 1079 00:49:35,150 --> 00:49:38,370 1080 00:49:38,370 --> 00:49:40,540 >> SAROO BRIERLEY (voiceover): Kien 26 sena ilu, 1081 00:49:40,540 --> 00:49:42,470 u I kien biss dwar li jduru 5. 1082 00:49:42,470 --> 00:49:45,465 Aħna qbilna li l-istazzjon tal-ferrovija u aħna mbarkat ferrovija tagħna flimkien. 1083 00:49:45,465 --> 00:49:48,010 My brother biss qal I ser jibqgħu hawn, u jien ser jiġu lura. 1084 00:49:48,010 --> 00:49:51,140 And I maħsub biss, ukoll taf, I tista 'ukoll biss tmur torqod 1085 00:49:51,140 --> 00:49:52,690 u hu ser biss jinxtegħel me up. 1086 00:49:52,690 --> 00:49:55,145 U meta I woke up li jmiss jum, il-ġarr kollu 1087 00:49:55,145 --> 00:49:59,125 kien vojt fuq ferrovija runaway, a ghost ferrovija tieħu me I do not know fejn. 1088 00:49:59,125 --> 00:50:01,980 1089 00:50:01,980 --> 00:50:06,280 >> I kien adottat out lejn l-Awstralja, għal familja Awstraljana. 1090 00:50:06,280 --> 00:50:09,710 U mom kien imżejjen my kamra mal-mappa ta 'l-Indja, 1091 00:50:09,710 --> 00:50:11,950 li hija tpoġġi jmiss għall komodina tiegħi. 1092 00:50:11,950 --> 00:50:15,830 I woke up kull filgħodu jaraw li mappa, u għalhekk 1093 00:50:15,830 --> 00:50:18,530 huwa tip ta tinżamm l-memorji ħajjin. 1094 00:50:18,530 --> 00:50:20,530 Nies ngħid, int jippruvaw isibu labra 1095 00:50:20,530 --> 00:50:23,560 fil haystack, Saroo int qatt ser issib lilha. 1096 00:50:23,560 --> 00:50:28,540 >> I d jkunu flashed tal-postijiet li I użati biex tmur, il-fwawar tal-familja tiegħi 1097 00:50:28,540 --> 00:50:29,890 tiffaċċja. 1098 00:50:29,890 --> 00:50:34,060 Ma kien hemm l-immaġni ta 'ommi, bilqiegħda mal tagħha saqajn qasmu, 1099 00:50:34,060 --> 00:50:35,740 biss jaraw cry tagħha. 1100 00:50:35,740 --> 00:50:38,160 Life huwa biss tant diffiċli. 1101 00:50:38,160 --> 00:50:41,237 Dan kien teżor tiegħi. 1102 00:50:41,237 --> 00:50:44,320 And I kienet tħares lejn Google Map u realizzati hemm Google Earth ukoll. 1103 00:50:44,320 --> 00:50:48,140 F'dinja fejn inti tista zoom fi, I beda jkollhom kollha ta 'dawn il-ħsibijiet 1104 00:50:48,140 --> 00:50:51,500 u liema possibbiltajiet li dan jista 'jagħmel għalija. 1105 00:50:51,500 --> 00:50:54,890 I qal li myself, inti taf, inti stajt ltqajna dawk memorji fotografiċi kollha 1106 00:50:54,890 --> 00:50:58,590 u postijiet familjari fejn int minn, u inti taf x'inhuma l-belt Dehra. 1107 00:50:58,590 --> 00:51:03,060 Dan jista 'jkun applikazzjoni li inti tista 'tuża biex issib triqtek lura. 1108 00:51:03,060 --> 00:51:06,720 >> Ħsibt, ukoll I ser tpoġġi dot fuq l-istazzjon tal-ferrovija Calcutta, 1109 00:51:06,720 --> 00:51:10,890 u linja raġġ, inti taf, li inti għandhom jiġu tiftix madwar dan il-qasam. 1110 00:51:10,890 --> 00:51:13,750 I sort tal sab dawn il-binarji tal-ferrovija. 1111 00:51:13,750 --> 00:51:18,160 U bdejt wara dan, u Wasalt għall stazzjon tal-ferrovija li 1112 00:51:18,160 --> 00:51:22,228 rifless l-istess immaġini li kien fil-memorji tiegħi. 1113 00:51:22,228 --> 00:51:23,707 Kollox mqabbla. 1114 00:51:23,707 --> 00:51:27,950 I maħsub biss Yep, I taf fejn jien ser. 1115 00:51:27,950 --> 00:51:30,116 Jien biss ser let l- Mappa li għandi in my head 1116 00:51:30,116 --> 00:51:33,080 ċomb me u jieħdu me lura għal Hometown tiegħi. 1117 00:51:33,080 --> 00:51:36,420 >> Wasalt għall-bieb ta ' l-dar li I twieled. 1118 00:51:36,420 --> 00:51:39,140 U mixi madwar madwar 15 metru madwar il-kantuniera, 1119 00:51:39,140 --> 00:51:42,980 kien hemm tliet onorevoli wieqfa barra, ħdejn xulxin. 1120 00:51:42,980 --> 00:51:47,830 U l-wieħed nofs intensifikati l quddiem, u I maħsub biss, dan huwa omm tiegħek. 1121 00:51:47,830 --> 00:51:53,450 Hi daħlet quddiem, hi hugged lili, u konna hemm għal madwar ħames minuti. 1122 00:51:53,450 --> 00:51:56,530 1123 00:51:56,530 --> 00:51:59,000 >> Hija grabbed naħa tiegħi u hi ħadet me lill-dar 1124 00:51:59,000 --> 00:52:02,450 u ltqajna fuq it-telefon, fejn hi rang sister tiegħi u my brother 1125 00:52:02,450 --> 00:52:05,600 li jgħidu li, tafu, brother tiegħek għandu biss 1126 00:52:05,600 --> 00:52:09,340 kollha f'daqqa deher bħal ghost. 1127 00:52:09,340 --> 00:52:12,440 U allura l-familja kienet tingħaqad mill-ġdid. 1128 00:52:12,440 --> 00:52:15,110 Kollox huwa kollha tajbin, I għen ommi out, 1129 00:52:15,110 --> 00:52:17,110 hi ma jkollhom jiġu slaving bogħod. 1130 00:52:17,110 --> 00:52:19,555 Hija jistgħu jgħixu l-bqija tal-ħajja tagħha fil-paċi. 1131 00:52:19,555 --> 00:52:23,460 >> Kien labra fil haystack, iżda l-labra kien hemm. 1132 00:52:23,460 --> 00:52:24,400 Kollox hemm. 1133 00:52:24,400 --> 00:52:28,260 Kollox aħna għandna fid-dinja hija fil-vit ta 'buttuna. 1134 00:52:28,260 --> 00:52:32,010 Imma inti ħadthom qbilna li jkollhom ir-rieda u d-determinazzjoni li jixtiequ dan. 1135 00:52:32,010 --> 00:52:32,950 >> [Daqq ta mużika] 1136 00:52:32,950 --> 00:52:36,420 1137 00:52:36,420 --> 00:52:38,170 DAVID Malan: Wonderfully testimonjali ħelu 1138 00:52:38,170 --> 00:52:40,540 biss dak li tista issa do mat-teknoloġija. 1139 00:52:40,540 --> 00:52:43,390 Aħna se tara int ġimgħa d-dieħla. 1140 00:52:43,390 --> 00:52:44,374