1 00:00:00,000 --> 00:00:02,670 >> [MUSIC TEMA] 2 00:00:02,670 --> 00:00:11,834 3 00:00:11,834 --> 00:00:13,365 >> SPEAKER 1: Hi, kulħadd. 4 00:00:13,365 --> 00:00:14,365 Merħba lura għat-taqsima. 5 00:00:14,365 --> 00:00:15,700 6 00:00:15,700 --> 00:00:18,700 Jum sabiħ out-- u huwa għalhekk li, jien żgur, hemm biss erba minnkom hawn 7 00:00:18,700 --> 00:00:21,180 u mhux tas-soltu pakkett tagħna. 8 00:00:21,180 --> 00:00:22,670 I ġew morda dan il-weekend. 9 00:00:22,670 --> 00:00:24,294 So I ma jkollhom starburst għalik guys. 10 00:00:24,294 --> 00:00:26,400 And I tista 'tibda sogħla terriblement matul dan. 11 00:00:26,400 --> 00:00:27,790 Hekk biss jkollhom miegħi. 12 00:00:27,790 --> 00:00:30,624 Jien ser verament jippruvaw u jiksbu permezz dan l-ewwel, 13 00:00:30,624 --> 00:00:32,290 għalkemm, qabel I jkollhom attakk sogħla. 14 00:00:32,290 --> 00:00:33,410 15 00:00:33,410 --> 00:00:37,390 Iżda biss jkun faċli fuqi a ftit bit-- li kollox nistaqsi. 16 00:00:37,390 --> 00:00:39,370 17 00:00:39,370 --> 00:00:44,289 >> Allura aġenda tagħna għal today-- biss reminder-- kwizz tiegħek huwa ġimgħa d-dieħla. 18 00:00:44,289 --> 00:00:46,830 I qallek dan ġimgħa li għaddiet hekk ma qabda inti off guard. 19 00:00:46,830 --> 00:00:47,954 Hekk jien fakkruha you again. 20 00:00:47,954 --> 00:00:49,180 Ġimgħa d-dieħla kwizz tiegħek. 21 00:00:49,180 --> 00:00:52,730 Biex dak il-għan, ġimgħa d-dieħla it-taqsima se jkun ferm aktar 22 00:00:52,730 --> 00:00:55,180 of-- I ser jippruvaw u jaħdmu f'xi reviżjoni. 23 00:00:55,180 --> 00:00:58,130 Hekk jekk inti guys tista għinni out mill jibghatni 24 00:00:58,130 --> 00:01:00,990 affarijiet li int komdu ma ', li int inkwetat dwar, 25 00:01:00,990 --> 00:01:03,530 suġġetti li inti tixtieq għall- me biex tkopri, li d jkun kbir. 26 00:01:03,530 --> 00:01:05,740 So I tista 'tipprova u jaħdmu magħhom fis-sezzjoni tagħna ġimgħa d-dieħla 27 00:01:05,740 --> 00:01:11,540 jew inti tibgħat materjal żejjed jew prep li inti ma tista 'tikseb xi mkien ieħor. 28 00:01:11,540 --> 00:01:12,150 >> Yeah! 29 00:01:12,150 --> 00:01:13,520 Aktar nies huma ġejjin! 30 00:01:13,520 --> 00:01:17,320 Ħsibt, ma nagħmel dan ħażin aħħar ġimgħa, li l-ebda wieħed irid li jiġu lura? 31 00:01:17,320 --> 00:01:18,065 Jien jibża. 32 00:01:18,065 --> 00:01:18,892 33 00:01:18,892 --> 00:01:21,100 Allura t-tliet affarijiet oħra li aħna qed tmur biex jmorru fuq 34 00:01:21,100 --> 00:01:24,850 huma ridirezzjoni, file I / O, u imbagħad pointers u l-memorja dinamika. 35 00:01:24,850 --> 00:01:29,160 Jien ċert int kollha super eċċitati dwar pointers-- suġġett favorit kulħadd, 36 00:01:29,160 --> 00:01:31,310 tant sempliċi biex jifhmu. 37 00:01:31,310 --> 00:01:33,130 Jien ċert li inti guys kollha ltqajna dan, id-dritt? 38 00:01:33,130 --> 00:01:39,510 >> Allura l-ewwel affarijiet ewwel, redirection-- dan huwa bażikament biss mod 39 00:01:39,510 --> 00:01:42,920 għall-kontroll kif inti input affarijiet fil-programm tiegħek, 40 00:01:42,920 --> 00:01:44,606 kif inti affarijiet output mill-programm tiegħek. 41 00:01:44,606 --> 00:01:46,980 Il-modi ewlenin li inti guys ġew interazzjoni magħha 42 00:01:46,980 --> 00:01:51,650 huwa biss permezz out standard bl-iskrin print tiegħek hawn. 43 00:01:51,650 --> 00:01:55,940 Iżda hemm modi biex pipe-- kif naraw hawn 44 00:01:55,940 --> 00:01:58,980 hija waħda tat-tip words-- tagħna ta 'pajp dik l-informazzjoni 45 00:01:58,980 --> 00:02:02,850 jew li d-data fis-fajl minn fajl. 46 00:02:02,850 --> 00:02:05,820 Huwa modi biss differenti ta ' jkollna affarijiet fil-programm tiegħek 47 00:02:05,820 --> 00:02:10,681 u barra mill-programm tiegħek, minflok biss tistamphom għal dan l-iskrin 48 00:02:10,681 --> 00:02:12,430 jew inputjar affarijiet mil-linja tal-kmand. 49 00:02:12,430 --> 00:02:13,760 50 00:02:13,760 --> 00:02:18,030 >> Allura l-ewwel waħda hija ftit akbar minn caret. 51 00:02:18,030 --> 00:02:22,085 Allura output-- hija biss prints l-output għall-fajl minflok l-iskrin tiegħek. 52 00:02:22,085 --> 00:02:23,620 53 00:02:23,620 --> 00:02:29,500 Hekk jekk kellek xi ħaġa li stampat "Hello, dinja!" għall-iskrin, 54 00:02:29,500 --> 00:02:32,400 jekk inti tpoġġi dan minflok li output.text, li 55 00:02:32,400 --> 00:02:35,220 toħloq dan il-fajl imsejħa output.text. 56 00:02:35,220 --> 00:02:38,550 U meta inti tiftaħ lilha, inneħħu jgħidu "Hello, dinja!" fil hemmhekk. 57 00:02:38,550 --> 00:02:41,410 Dan jista 'jkun super utli jekk għandek ton ta 'żbalji 58 00:02:41,410 --> 00:02:43,430 attwalment, kif naraw f'dan il-wieħed. 59 00:02:43,430 --> 00:02:46,810 Jekk inti tagħmel żewġ caret, inneħħu jistampaw il-messaġġi ta 'żball. 60 00:02:46,810 --> 00:02:52,090 >> Hekk jekk int li għandhom problema bl kompilazzjoni, li għandu ħafna ta 'żbalji 61 00:02:52,090 --> 00:02:56,770 u int jkollna bogged fil jippruvaw li tiskrollja permezz ta 'fil-kmand linja tiegħek 62 00:02:56,770 --> 00:02:59,110 permezz tagħhom kollha, inti tista ' biss tipprintjahom għall-fajl, 63 00:02:59,110 --> 00:03:02,130 jiftħu dan il-fajl sabiex inti tista iscroll permezz tagħhom aktar faċli. 64 00:03:02,130 --> 00:03:05,160 I attwalment użati li meta ħafna I kien debugging 65 00:03:05,160 --> 00:03:07,970 181 psets tiegħi għat-tagħlim magna. 66 00:03:07,970 --> 00:03:10,000 Għalhekk jista 'jkun super utli aktar tard. 67 00:03:10,000 --> 00:03:18,370 Huwa wkoll utli jekk għandek program li forsi qed jiġġenera librerija 68 00:03:18,370 --> 00:03:20,430 jew jiġġeneraw xi sett ta 'kordi, u int 69 00:03:20,430 --> 00:03:22,846 jeħtieġ li tkun kapaċi li tara li huwa jiġġeneraw lilhom kif suppost. 70 00:03:22,846 --> 00:03:23,860 71 00:03:23,860 --> 00:03:25,160 Dan huwa l-mod biex tagħmel dan. 72 00:03:25,160 --> 00:03:28,280 >> Mela jekk inti tipprintjahom għall-fajl, inti tista 'iktar faċilment jeżaminahom, id-dritt? 73 00:03:28,280 --> 00:03:30,930 Versus jippruvaw li tiskrollja permezz kmand linja tiegħek. 74 00:03:30,930 --> 00:03:32,740 75 00:03:32,740 --> 00:03:35,820 U mbagħad ħaġa waħda li wieħed jinnota hija li biss mal-akbar 76 00:03:35,820 --> 00:03:40,090 milli caret, jekk inti qed tikteb għal fajl li diġà exists-- 77 00:03:40,090 --> 00:03:44,990 hekk simili jekk aħna dam dan l-ewwel żmien, aħna poġġih għall output.text, 78 00:03:44,990 --> 00:03:49,970 u mbagħad kellna t-tieni programm li stampat dan bħala programm tnejn 79 00:03:49,970 --> 00:03:54,250 u għamlet akbar milli output.text, se jissostitwixxu that-- hekk 80 00:03:54,250 --> 00:03:56,715 jissostitwixxu dak li kien qatt dan il-fajl biex tibda bil. 81 00:03:56,715 --> 00:03:57,720 82 00:03:57,720 --> 00:04:00,750 >> Mela jekk inti tixtieq li tehmeż għal fajl, kif naraw hawn, 83 00:04:00,750 --> 00:04:04,779 inti biss tagħmel żewġ akbar minn sinjali. 84 00:04:04,779 --> 00:04:05,820 U se tehmez ma 'din. 85 00:04:05,820 --> 00:04:06,750 Dan mhux se jissostitwixxu dan. 86 00:04:06,750 --> 00:04:09,770 Mela jekk għandek bżonn biex imexxu multipli programmi u tip ta 'jżomm 87 00:04:09,770 --> 00:04:13,170 rekord ta 'dak kollha kemm huma jirritornaw lilek fil-fajl, 88 00:04:13,170 --> 00:04:14,190 li l-mod biex tagħmel dan. 89 00:04:14,190 --> 00:04:17,231 Jekk inti ma 'kura x'hemm fil-fajl tiegħek u huwa permess li jinkitbu fuqhom, 90 00:04:17,231 --> 00:04:19,204 inti tista 'biss użu akbar wieħed minn. 91 00:04:19,204 --> 00:04:20,600 Ma li jagħmel sens għal kulħadd? 92 00:04:20,600 --> 00:04:23,205 93 00:04:23,205 --> 00:04:31,140 >> UDJENZA: Bħal dot mmejla bonjour akbar milli l-produzzjoni dot test, bħal darbtejn, 94 00:04:31,140 --> 00:04:34,030 inneħħu biss juru biss fuq il-produzzjoni dot test tieni time-- 95 00:04:34,030 --> 00:04:34,810 >> SPEAKER 1: Dritt. 96 00:04:34,810 --> 00:04:40,450 Għalhekk ikun bażikament biss kompletament jissostitwixxu dak li kien hemm biex tibda bil. 97 00:04:40,450 --> 00:04:44,260 Jekk dan il-fajl hawn, il- output.text diġà 98 00:04:44,260 --> 00:04:48,230 teżisti, bażikament tkun xi tkun inti sejħa li għal darb'oħra ma 'akbar waħda 99 00:04:48,230 --> 00:04:51,920 milli inti tista 'biss jaħsbu ta' dan kif bhalu sostitwit il-fajl. 100 00:04:51,920 --> 00:04:54,824 Bħal meta int iffrankar Word dokument u inti tiffranka bħala, 101 00:04:54,824 --> 00:04:57,365 u inti żżomm l-istess isem, u kompletament overwrites it-- 102 00:04:57,365 --> 00:04:58,680 dan huwa l-istess tip ta 'ħaġa. 103 00:04:58,680 --> 00:05:00,380 104 00:05:00,380 --> 00:05:03,550 Kull min ikollu xi mistoqsijiet dwar biss outputting għall-fajl? 105 00:05:03,550 --> 00:05:05,051 106 00:05:05,051 --> 00:05:05,550 Biża. 107 00:05:05,550 --> 00:05:11,440 >> Allura ovvjament, jekk inti reverse l- vleġġa direzzjoni, hija tista 'tagħmel kontribut. 108 00:05:11,440 --> 00:05:13,090 109 00:05:13,090 --> 00:05:19,960 Allura meta inti guys kellhom bħal Caesar jew Visioneer 110 00:05:19,960 --> 00:05:23,195 u inti kellhom xi ħaġa input, kellek argument linja tal-kmand 111 00:05:23,195 --> 00:05:24,960 li attwalment input. 112 00:05:24,960 --> 00:05:27,410 Dan huwa mod ieħor biex tagħmel dan. 113 00:05:27,410 --> 00:05:30,520 Allura minflok ta 'stennija għal kmand pront, 114 00:05:30,520 --> 00:05:33,800 bħal meta inti tlabt għall tiegħek messaġġ fi Caesar jew Visioneer, 115 00:05:33,800 --> 00:05:36,490 jekk kellek fajl test li kellhom il-messaġġ tiegħek, 116 00:05:36,490 --> 00:05:38,280 inti tista 'biss tip li fil dak. 117 00:05:38,280 --> 00:05:44,930 >> Hekk jekk dan kien simili dot mmejla Caesar 3 anqas minn test input vleġġa, li 118 00:05:44,930 --> 00:05:47,240 huwa messaġġ tiegħek, li imur biss multa. 119 00:05:47,240 --> 00:05:51,310 120 00:05:51,310 --> 00:05:54,020 Meta program Caesar tiegħek attwalment talab għal input mill-utent, 121 00:05:54,020 --> 00:05:57,360 ikun diġà għandhom dan għaliex inti stajt ittajpjat f'dan il-fajl. 122 00:05:57,360 --> 00:05:58,830 Li jinsab biss mod ieħor. 123 00:05:58,830 --> 00:06:02,445 Just a reverse ta output-- biss input għal data tiegħek. 124 00:06:02,445 --> 00:06:04,570 125 00:06:04,570 --> 00:06:06,680 >> U allura l-aħħar wieħed huwa pajp. 126 00:06:06,680 --> 00:06:07,780 Hekk jibred pretty dan wieħed. 127 00:06:07,780 --> 00:06:09,890 Għaliex din tippermetti li inti jieħdu l-output ta 'wieħed 128 00:06:09,890 --> 00:06:13,695 programm u poġġih bħala input għal programm ieħor. 129 00:06:13,695 --> 00:06:15,250 130 00:06:15,250 --> 00:06:18,630 I do not know jekk kwalunkwe inti lagħbu l jiddeċifraw 131 00:06:18,630 --> 00:06:20,590 li CS50 jista 'jkollhom tak, iżda jkun 132 00:06:20,590 --> 00:06:27,380 jippermettu li tieħu xi kampjun fajl, tip li fil encryption tiegħek, 133 00:06:27,380 --> 00:06:30,350 u mbagħad minn hemm tip li fis decryption tiegħek 134 00:06:30,350 --> 00:06:32,470 tagħmel żgur li rriżulta l-istess. 135 00:06:32,470 --> 00:06:34,050 Allura huwa tip simili three-way loop. 136 00:06:34,050 --> 00:06:38,400 137 00:06:38,400 --> 00:06:39,423 Mur għaliha. 138 00:06:39,423 --> 00:06:41,785 >> UDJENZA: Jekk programm għandha inputs multipli, 139 00:06:41,785 --> 00:06:47,646 hemm mod li tgħid dan li input li tuża l-fajl test jew l-output għall? 140 00:06:47,646 --> 00:06:49,325 >> SPEAKER 1: Hija għandha inputs multipli. 141 00:06:49,325 --> 00:06:52,190 142 00:06:52,190 --> 00:07:00,430 Tkun xi tkun fajl input-- tiegħek meta huwa titlob għall-input li l-ewwel darba, huwa 143 00:07:00,430 --> 00:07:03,240 ser jassumi, naħseb, huwa ser pajp fil-fajl kollu. 144 00:07:03,240 --> 00:07:03,979 145 00:07:03,979 --> 00:07:07,145 Mela jekk għandek inputs multipli, int ser ikunu pajpijiet fil-fajls multipli. 146 00:07:07,145 --> 00:07:08,190 147 00:07:08,190 --> 00:07:12,390 Mela jekk inti qed tistaqsi għall-messaġġi tliet darbiet fil-kodiċi tiegħek, 148 00:07:12,390 --> 00:07:15,230 int ser tkun tqegħid fi tliet fajls differenti. 149 00:07:15,230 --> 00:07:15,980 U jiġrilha crazy. 150 00:07:15,980 --> 00:07:18,188 U inti ma għandu jkollhom joqogħdu jinkwetaw dwar dak id-dritt issa. 151 00:07:18,188 --> 00:07:19,150 Iżda li l-idea. 152 00:07:19,150 --> 00:07:20,680 153 00:07:20,680 --> 00:07:26,822 >> Allura yeah, pajp ikun output biss ta 'wieħed programm juża input fil--oħra. 154 00:07:26,822 --> 00:07:27,665 Kulħadd tajba hemmhekk? 155 00:07:27,665 --> 00:07:28,565 156 00:07:28,565 --> 00:07:29,065 Kessaħ. 157 00:07:29,065 --> 00:07:30,170 158 00:07:30,170 --> 00:07:30,932 OK. 159 00:07:30,932 --> 00:07:32,890 Inti probabilment mhux se jkollhom li tagħmel wisq magħha. 160 00:07:32,890 --> 00:07:35,670 Imma għandek tifhem modi kif inti tista 'tuża dan. 161 00:07:35,670 --> 00:07:38,910 U hemm xi każijiet li inti tista 'tixtieq li tagħmel użu minnha. 162 00:07:38,910 --> 00:07:44,590 >> So fajl I / O-- Naf dak li qed saying-- aħna qed jintużaw biex taqra minn 163 00:07:44,590 --> 00:07:50,500 u l-kitba għall-iskrin tagħna hemm, liema tkun standard u standard out. 164 00:07:50,500 --> 00:07:54,370 U dan huwa dak li inti guys kienu tagħmel mill-bidu tal-klassi hawn. 165 00:07:54,370 --> 00:07:58,220 Iżda int tista 'wkoll jaqraw u jiktbu fajls, li hija kollha fajl I / O-- hekk input fajl, 166 00:07:58,220 --> 00:07:59,850 output hija kollha li stands għall. 167 00:07:59,850 --> 00:08:00,930 168 00:08:00,930 --> 00:08:04,360 Allura dan bażikament ifisser li inti jista 'jaħżen data tiegħek issa. 169 00:08:04,360 --> 00:08:08,460 >> Meta inti biss jistampaw il- iskrin, huwa bażikament marret, id-dritt? 170 00:08:08,460 --> 00:08:12,507 Hekk kif inti tagħmel "Hello dinja "u run" Hello dinja " 171 00:08:12,507 --> 00:08:14,090 prints "Hello dinja" għall-iskrin. 172 00:08:14,090 --> 00:08:16,370 Imma inti ma tistax verament tagħmel xejn magħha minn hemm. 173 00:08:16,370 --> 00:08:18,950 Jekk int taħżen f'test fajl, imbagħad f'daqqa waħda 174 00:08:18,950 --> 00:08:22,789 inti għandek din id-data li int permess li jimmanipulaw jew it-tqegħid fis-fajl, 175 00:08:22,789 --> 00:08:24,080 jew poġġih fi programm aktar tard. 176 00:08:24,080 --> 00:08:26,370 177 00:08:26,370 --> 00:08:29,290 Waħda mir-raġunijiet għaliex aħna nagħmlu dan huwa biss 178 00:08:29,290 --> 00:08:31,560 bħala mod biex jaħżen id-data għal użu aktar tard. 179 00:08:31,560 --> 00:08:34,790 180 00:08:34,790 --> 00:08:37,279 >> I jkollhom koppja ta 'passi hawn ftit mixi permezz standard 181 00:08:37,279 --> 00:08:39,450 I / O. Fi stadju wieħed, inti bżonn li jinħoloq referenza 182 00:08:39,450 --> 00:08:43,480 għall-fajl ma ' tappijiet Fajl stilla. 183 00:08:43,480 --> 00:08:45,740 Allura li toħloq pointer għall-fajl. 184 00:08:45,740 --> 00:08:48,080 185 00:08:48,080 --> 00:08:49,650 Mela allura inti tixtieq li tiftħu. 186 00:08:49,650 --> 00:08:52,940 U inti tgħidli, litteralment, biss fajl ugwali fopen. 187 00:08:52,940 --> 00:08:57,400 U dan se jirritornaw pointer li l-fajl inti biss miftuħa. 188 00:08:57,400 --> 00:08:59,610 189 00:08:59,610 --> 00:09:01,460 Rajt koppja tal inti guys fil-ħinijiet uffiċċju. 190 00:09:01,460 --> 00:09:07,400 >> Iżda waħda mill-affarijiet huwa pointers remember-- 191 00:09:07,400 --> 00:09:10,409 jistgħu jkunu xi wħud indirizz jew null, id-dritt? 192 00:09:10,409 --> 00:09:12,700 Jekk aħna qatt każ fejn xi ħaġa tista 'tmur lura null, 193 00:09:12,700 --> 00:09:14,990 dak li għandna nagħmlu qabel we qatt tużah? 194 00:09:14,990 --> 00:09:16,220 195 00:09:16,220 --> 00:09:19,000 Għandna bżonn li jiċċekkja jekk huwa null jew le, id-dritt? 196 00:09:19,000 --> 00:09:23,600 Minħabba li xi wħud jista 'jkollok kellhom il-kwistjoni fejn kwalunkwe oġġett 197 00:09:23,600 --> 00:09:26,110 kien qed lura fl-tbegħid kien null. 198 00:09:26,110 --> 00:09:28,170 Inti ppruvaw biex iwettqu xi funzjoni fuqha. 199 00:09:28,170 --> 00:09:29,770 U s-sit tal-kompjuter tiegħek akkużati. 200 00:09:29,770 --> 00:09:30,725 Dritt? 201 00:09:30,725 --> 00:09:33,640 I bet koppja tal inti seta 'kellu din il-kwistjoni. 202 00:09:33,640 --> 00:09:38,890 >> Allura ma fopen, fopen se la ritorn pointer għall-fajl, 203 00:09:38,890 --> 00:09:41,200 jew jekk xi ħaġa tmur ħażin, li għaddej biex jirritorna null. 204 00:09:41,200 --> 00:09:45,980 Allura inti dejjem bżonn li jiċċekkja li ma rritornax null 205 00:09:45,980 --> 00:09:47,880 qabel ma int tipprova li tagħmel xi ħaġa oħra. 206 00:09:47,880 --> 00:09:49,110 207 00:09:49,110 --> 00:09:51,974 Dan huwa simili paradigma standard li int ser bżonn hawn. 208 00:09:51,974 --> 00:09:54,390 Jekk qatt hemm ċans li xi ħaġa jista 'ritorn null, 209 00:09:54,390 --> 00:09:56,590 jivverifika sabiex ikun żgur li ma qabel inti tipproċedi. 210 00:09:56,590 --> 00:09:58,911 Inkella, int ser biex tikseb difetti sit sabiħ. 211 00:09:58,911 --> 00:10:00,410 U l-ebda wieħed jħobb biex jittrattaw ma 'dawk. 212 00:10:00,410 --> 00:10:03,180 213 00:10:03,180 --> 00:10:06,410 >> Allura kif naraw hawn, l-ewwel argument huwa biss il-passaġġ għall-fajl. 214 00:10:06,410 --> 00:10:09,380 Jekk dan il-fajl ma teżistix, li għaddej biex joħolqu dan il-fajl. 215 00:10:09,380 --> 00:10:10,713 U huwa biss se tkun vojta. 216 00:10:10,713 --> 00:10:10,789 217 00:10:10,789 --> 00:10:13,080 U allura l-tieni argument huwa l-mod li tixtieq. 218 00:10:13,080 --> 00:10:14,610 Do irridu li jinqara mill dan il-fajl? 219 00:10:14,610 --> 00:10:15,560 Do inti tixtieq li tikteb minnha? 220 00:10:15,560 --> 00:10:16,476 Do inti tixtieq li tehmeż? 221 00:10:16,476 --> 00:10:17,600 222 00:10:17,600 --> 00:10:20,670 Allura fil-fatt dak I biss said-- jekk il-fajl ma teżistix 223 00:10:20,670 --> 00:10:23,400 u int tipprova li jaqra minn dan, huwa għaddej biex tarmi żball. 224 00:10:23,400 --> 00:10:26,890 Jekk il-fajl name-- simili jekk file.text s'issa ma jeżistix 225 00:10:26,890 --> 00:10:29,250 u inti tixtieq li jiktbu lilha, dan se joħloq 226 00:10:29,250 --> 00:10:33,110 fajl vojt imsejjaħ file.text għalik. 227 00:10:33,110 --> 00:10:36,612 U jekk inti tixtieq li tehmeż, inti għandek tagħmel l-istess ħaġa. 228 00:10:36,612 --> 00:10:38,081 Ma li jagħmel sens? 229 00:10:38,081 --> 00:10:40,580 Jekk inti qed tipprova li jaqra minn fajl li s'issa ma jeżistix, 230 00:10:40,580 --> 00:10:41,590 dan ser tarmi żball. 231 00:10:41,590 --> 00:10:44,340 Inkella, dan se joħloq il-fajl għal inti tagħmel dak li trid għaliha. 232 00:10:44,340 --> 00:10:45,970 233 00:10:45,970 --> 00:10:46,470 Kessaħ. 234 00:10:46,470 --> 00:10:47,510 235 00:10:47,510 --> 00:10:48,880 Issa nistgħu jinqara mill-fajl. 236 00:10:48,880 --> 00:10:52,570 U dan huwa biss tip ta 'għaddej permezz tal-funzjonijiet differenti 237 00:10:52,570 --> 00:10:58,980 li għandna għall-fajl I / O. Dan se jkun meħtieġ pset din il-ġimgħa, 238 00:10:58,980 --> 00:11:00,505 jekk niftakar sewwa. 239 00:11:00,505 --> 00:11:02,880 Iva, assolutament se jkun meħtieġ pset din il-ġimgħa. 240 00:11:02,880 --> 00:11:04,260 241 00:11:04,260 --> 00:11:07,010 Allura fgetc jirritorna l-karattru li jmiss. 242 00:11:07,010 --> 00:11:08,350 243 00:11:08,350 --> 00:11:10,300 fgets jirritorna linja ta 'test. 244 00:11:10,300 --> 00:11:11,790 245 00:11:11,790 --> 00:11:14,610 Huwa ser jerġa xejn sa linja ġdida, u se break. 246 00:11:14,610 --> 00:11:15,950 247 00:11:15,950 --> 00:11:18,700 Allura fread jaqra ċertu numru ta 'bytes u tpoġġihom 248 00:11:18,700 --> 00:11:20,700 fi array, li hija xi ħaġa inti tista ' 249 00:11:20,700 --> 00:11:25,485 trid tagħmel il-size-- ri jista 'jkun utli. 250 00:11:25,485 --> 00:11:26,550 251 00:11:26,550 --> 00:11:29,290 >> Kif ħafna nies qrajt l-spec pset, mill-mod? 252 00:11:29,290 --> 00:11:30,980 253 00:11:30,980 --> 00:11:32,261 OK. 254 00:11:32,261 --> 00:11:32,760 [Inaudible] 255 00:11:32,760 --> 00:11:35,380 256 00:11:35,380 --> 00:11:36,580 >> SPEAKER 1: OK. 257 00:11:36,580 --> 00:11:37,530 Kull dritt. 258 00:11:37,530 --> 00:11:41,940 Żgur taqra that-- huwa pset gost. 259 00:11:41,940 --> 00:11:51,320 Ikollok biex tirkupra mħassra memorja card-- verament eċċitanti meta taħdem. 260 00:11:51,320 --> 00:11:54,100 Iżda ċert, tibda qari dan. 261 00:11:54,100 --> 00:11:56,280 Come tkellem lili jekk inti xi mistoqsijiet dwar dan. 262 00:11:56,280 --> 00:11:59,290 >> OK, hekk kif kien qal, fread jaqra ċertu numru ta 'bytes. 263 00:11:59,290 --> 00:12:01,340 264 00:12:01,340 --> 00:12:03,590 C'est xi numru arbitrarju li int ser jistabbilixxu. 265 00:12:03,590 --> 00:12:05,990 266 00:12:05,990 --> 00:12:08,260 U mbagħad fseek biss jiċċaqlaq għal ċerta pożizzjoni. 267 00:12:08,260 --> 00:12:11,150 Allura forsi inti ma 'kura dwar l-10 bytes li jmiss. 268 00:12:11,150 --> 00:12:12,880 Inti biss jixtiequ li skip quddiem. 269 00:12:12,880 --> 00:12:14,030 Inti ma jimpurtahom dwar dawk. 270 00:12:14,030 --> 00:12:16,280 Inti tixtieq li taqra jibda byte 11. 271 00:12:16,280 --> 00:12:18,252 fseek tippermetti li tagħmel dan. 272 00:12:18,252 --> 00:12:20,710 Għalhekk tippermetti li inti tkun selettiva dwar dak li int qari. 273 00:12:20,710 --> 00:12:25,880 Minħabba fgetc, fgets, u aqra fread minn ċertu post fil-fajl. 274 00:12:25,880 --> 00:12:27,260 275 00:12:27,260 --> 00:12:35,090 >> A mod biex jaħsbu dwar dan hija jekk din huwa fajl tagħna, meta inti l-ewwel tiftħu, 276 00:12:35,090 --> 00:12:41,140 inti għandek din il-pożizzjoni fil-fajl li jibda fil-bidu. 277 00:12:41,140 --> 00:12:45,040 Kull meta inti sejħa fgetc, fgetf, jew fread, 278 00:12:45,040 --> 00:12:48,875 li għaddej biex tibda minn dan il-markatur pożizzjoni. 279 00:12:48,875 --> 00:12:51,340 280 00:12:51,340 --> 00:12:55,245 Ejja ngħidu li inti biss trid taqra din blokki ta 'memorja hawn fuq. 281 00:12:55,245 --> 00:12:56,300 282 00:12:56,300 --> 00:12:57,960 Inti ma tistax biss sejħa. 283 00:12:57,960 --> 00:13:02,430 Int għandek tfittex hawn fuq u mbagħad jaqra minn hemm 284 00:13:02,430 --> 00:13:06,540 jew taqra, gets, jew getc, jiddependi fuq dak li trid. 285 00:13:06,540 --> 00:13:09,310 Allura tfittex biss tippermetti li inti skip porzjonijiet ta 'memorja. 286 00:13:09,310 --> 00:13:11,590 U li l-uniku mod inti tista 'skip-affarijiet 287 00:13:11,590 --> 00:13:14,012 mingħajr qari tagħhom fiċ buffer tiegħek. 288 00:13:14,012 --> 00:13:15,470 Ma li jagħmel sens għal kulħadd? 289 00:13:15,470 --> 00:13:21,110 290 00:13:21,110 --> 00:13:24,780 >> Ovvjament, hemm lott ta 'here-- parallel 291 00:13:24,780 --> 00:13:27,780 ridirezzjoni output, jew input tagħna, inti qrajt u jiktbu. 292 00:13:27,780 --> 00:13:31,800 Allura fputc biss jikteb karattru fil-fajl. 293 00:13:31,800 --> 00:13:33,655 fputs jikteb linja. 294 00:13:33,655 --> 00:13:35,030 295 00:13:35,030 --> 00:13:37,420 Fprintf prints output ifformattjat. 296 00:13:37,420 --> 00:13:41,190 Mela jekk għandek tabs, jew spazju, jew whatnot. 297 00:13:41,190 --> 00:13:44,180 U mbagħad fwrite jikteb xi firxa ta 'bytes għal fajl. 298 00:13:44,180 --> 00:13:48,860 Allura dan huwa l-istess mod fwrite u fread huma analogi 299 00:13:48,860 --> 00:13:57,550 fgets opposites--, fputs, u imbagħad lottijiet fputc u fgetc-- 300 00:13:57,550 --> 00:14:00,710 ta 'crazy, affarijiet malajr. 301 00:14:00,710 --> 00:14:05,300 >> Biss tip ta 'jżomm dan handy-- inti ser ikollok żminijiet differenti 302 00:14:05,300 --> 00:14:08,680 fejn forsi inti biss trid karattru wieħed kull darba. 303 00:14:08,680 --> 00:14:09,890 Forsi inti tixtieq linja kollha. 304 00:14:09,890 --> 00:14:14,320 Bil pset-- dizzjunarju tiegħek li huwa f'żewġ psets, 305 00:14:14,320 --> 00:14:19,690 Nemmen, aħna nagħtuk kollu dizzjunarju f'format test 306 00:14:19,690 --> 00:14:22,252 li għandha kull kelma separati minn linja. 307 00:14:22,252 --> 00:14:24,210 Hekk jekk int riedu li taqra f'kelma waħda fi żmien, 308 00:14:24,210 --> 00:14:31,769 dak li jista inti tuża jekk inti qed taqra u dawn qed kollha separata fuq linji ġodda, 309 00:14:31,769 --> 00:14:33,310 u inti biss tixtieq kelma waħda fi żmien? 310 00:14:33,310 --> 00:14:35,320 311 00:14:35,320 --> 00:14:36,040 >> Udjenza: Fgets 312 00:14:36,040 --> 00:14:36,748 >> SPEAKER 1: Dritt. 313 00:14:36,748 --> 00:14:39,960 Fgets-- minħabba li jirritorna dak kollu li huwa fuq linja waħda. 314 00:14:39,960 --> 00:14:42,750 U jekk kull kelma hija tagħha linja stess, nistgħu nużaw fgets. 315 00:14:42,750 --> 00:14:44,511 316 00:14:44,511 --> 00:14:45,010 Kessaħ. 317 00:14:45,010 --> 00:14:47,290 Ma li jagħmel sens, kulħadd? 318 00:14:47,290 --> 00:14:48,020 Kessaħ? 319 00:14:48,020 --> 00:14:50,020 Yeah, aħna qed tmur biex jiksbu l-parti gost ma pointers 320 00:14:50,020 --> 00:14:51,728 malajr ħafna, fejn inti nikseb biex jagħmlu xi matematika. 321 00:14:51,728 --> 00:14:52,776 U dan ser ikun kbir. 322 00:14:52,776 --> 00:14:55,690 323 00:14:55,690 --> 00:14:57,740 >> Aħħar step-- qrib fajl tiegħek. 324 00:14:57,740 --> 00:15:01,090 Bil-ħafna affarijiet hawn, wieħed ta 'mudelli tagħna 325 00:15:01,090 --> 00:15:03,550 huwa jekk jista 'ritorn null, iċċekkja għall null. 326 00:15:03,550 --> 00:15:06,160 Jekk inti tiftaħ xi ħaġa, youd aħjar tagħlaqha. 327 00:15:06,160 --> 00:15:10,419 OK, hekk int ma jsirx sakemm int isir sakemm inti ħadthom magħluqa din. 328 00:15:10,419 --> 00:15:12,585 Tip simili mhuwiex aktar sakemm il-mara xaħam sings. 329 00:15:12,585 --> 00:15:14,130 C'est simili għeluq fajl tiegħek. 330 00:15:14,130 --> 00:15:16,860 331 00:15:16,860 --> 00:15:19,190 Kif jgħid hawnhekk, biss itenni, dejjem 332 00:15:19,190 --> 00:15:21,750 tiftaħ fajl tiegħek qabel int qari jew kitba lilha. 333 00:15:21,750 --> 00:15:24,450 U dejjem qrib dan jekk inti stajt fetħuh. 334 00:15:24,450 --> 00:15:25,460 Kull dritt? 335 00:15:25,460 --> 00:15:25,960 Kessaħ. 336 00:15:25,960 --> 00:15:26,835 >> Allura hawnhekk eżempju. 337 00:15:26,835 --> 00:15:29,250 338 00:15:29,250 --> 00:15:34,330 So tiny-- I do not know jekk inti guys jista 'jara li tajjeb ħafna. 339 00:15:34,330 --> 00:15:36,805 Jekk biss nistgħu tiżdied l-luminożità b'xi. 340 00:15:36,805 --> 00:15:40,430 341 00:15:40,430 --> 00:15:45,030 Let me attwalment tagħmel dan jekk nista '. 342 00:15:45,030 --> 00:15:48,020 343 00:15:48,020 --> 00:15:51,470 OK, inti guys ma tistax verament tara li fil-livelli kollha, inti tista? 344 00:15:51,470 --> 00:15:52,905 OK, aħna qed tmur biex tagħmel dan, imbagħad. 345 00:15:52,905 --> 00:16:35,094 346 00:16:35,094 --> 00:16:35,594 [Inaudible] 347 00:16:35,594 --> 00:16:56,670 348 00:16:56,670 --> 00:16:58,605 >> I jassumi li dan huwa ħafna aħjar biex tara. 349 00:16:58,605 --> 00:17:17,330 350 00:17:17,330 --> 00:17:19,455 Jista 'xi ħadd tara fejn tiegħi ġurdien marru hija l-kwistjoni? 351 00:17:19,455 --> 00:17:22,837 Ah, hemm it is-- dak ġlidiet! 352 00:17:22,837 --> 00:17:48,910 353 00:17:48,910 --> 00:17:49,520 >> OK. 354 00:17:49,520 --> 00:17:53,845 Bażikament, inti guys għandu jkollhom tip ta 'idea ta' dak li dan qed tagħmel. 355 00:17:53,845 --> 00:17:56,740 356 00:17:56,740 --> 00:17:57,600 Huwa mhux perfett. 357 00:17:57,600 --> 00:17:58,851 358 00:17:58,851 --> 00:18:02,425 Imma I d pjuttost jispjegaw dan milli jonfqu aktar ħin jippruvaw format kif suppost. 359 00:18:02,425 --> 00:18:03,610 360 00:18:03,610 --> 00:18:07,280 Bażikament, kif tara hawn, nibdew il-fajl miftuħ. 361 00:18:07,280 --> 00:18:09,620 U aħna għandna xi fajl database li aħna 362 00:18:09,620 --> 00:18:12,300 ftuħ li jgħid li l-istudenti tagħna. 363 00:18:12,300 --> 00:18:14,020 U aħna qed tmur biex jiktbu lilha. 364 00:18:14,020 --> 00:18:15,060 365 00:18:15,060 --> 00:18:17,720 Allura naturalment, ritorn null. 366 00:18:17,720 --> 00:18:19,650 Allura aħna għandna biex jiċċekkjaw għall null. 367 00:18:19,650 --> 00:18:22,930 U allura jekk mhuwiex null, aħna jgħaddu. 368 00:18:22,930 --> 00:18:25,660 U kif tara, aħna qed looping permezz ta 'hawn. 369 00:18:25,660 --> 00:18:26,960 Hemm studenti. 370 00:18:26,960 --> 00:18:30,520 -Istudenti huwa hash definit bħala tlieta. 371 00:18:30,520 --> 00:18:34,060 U dak li aħna qed tagħmel hija aħna istampar għall-fajl, id-dritt? 372 00:18:34,060 --> 00:18:36,975 Allura dak li aħna istampar għall-fajl tagħna? 373 00:18:36,975 --> 00:18:47,040 374 00:18:47,040 --> 00:18:48,906 >> UDJENZA: Il-punteġġi li huma fil-firxa? 375 00:18:48,906 --> 00:18:49,680 >> SPEAKER 1: Yeah. 376 00:18:49,680 --> 00:18:50,980 Il-punteġġi li huma l array-- eżattament. 377 00:18:50,980 --> 00:18:53,050 Allura aħna ftuħ dan fajl database, li 378 00:18:53,050 --> 00:18:56,040 I jassumi huwa xi tip ta 'database gradi. 379 00:18:56,040 --> 00:19:01,100 U aħna qed biss istampar l- punteġġi ta 'kull student biex dan il-fajl. 380 00:19:01,100 --> 00:19:02,140 Kessaħ? 381 00:19:02,140 --> 00:19:02,640 Tajba. 382 00:19:02,640 --> 00:19:03,811 383 00:19:03,811 --> 00:19:04,310 Biża. 384 00:19:04,310 --> 00:19:05,100 OK. 385 00:19:05,100 --> 00:19:06,950 Ejja nneħħu lura to-- 386 00:19:06,950 --> 00:19:08,646 >> UDJENZA: Għandi mistoqsija ta 'malajr. 387 00:19:08,646 --> 00:19:11,570 Huwa l-printf mhux fil-għall-loop? 388 00:19:11,570 --> 00:19:12,870 Li jinsab biss fil-jekk loop? 389 00:19:12,870 --> 00:19:14,370 SPEAKER 1: Le, huwa fil-għal loop. 390 00:19:14,370 --> 00:19:16,150 391 00:19:16,150 --> 00:19:18,810 Ma nistax nara ġurdien tiegħi tajjeb ħafna up here. 392 00:19:18,810 --> 00:19:21,359 Hekk jien qed jitħabtu biex format li suppost. 393 00:19:21,359 --> 00:19:22,525 Dan bracket għandu tkun marret. 394 00:19:22,525 --> 00:19:23,610 395 00:19:23,610 --> 00:19:25,130 Għandu jkun stabbiliti hawn. 396 00:19:25,130 --> 00:19:26,605 Dan huwa x'hemm fil tiegħek għal loop. 397 00:19:26,605 --> 00:20:10,680 398 00:20:10,680 --> 00:20:11,180 Hemmhekk. 399 00:20:11,180 --> 00:20:12,160 Issa huwa pjuttost. 400 00:20:12,160 --> 00:20:16,720 Allura li l-mod kif għandu be-- ħlief għal din l-aħħar kategorija li I miċħud. 401 00:20:16,720 --> 00:20:17,220 OK. 402 00:20:17,220 --> 00:20:19,491 Ma li jagħmel sens għal kulħadd? 403 00:20:19,491 --> 00:20:19,990 OK. 404 00:20:19,990 --> 00:20:23,750 Aħna qed tmur biex jimxu fuq għall-ħaġa li jmiss then-- 405 00:20:23,750 --> 00:20:26,180 li, fil-fatt, int ser biex bżonn biex tara l-kodiċi. 406 00:20:26,180 --> 00:20:28,370 Hekk jien biss se kopja li aktar dritt issa. 407 00:20:28,370 --> 00:20:31,500 408 00:20:31,500 --> 00:20:32,000 OK. 409 00:20:32,000 --> 00:20:35,110 Hekk jien ser nuruk guys dan il-kodiċi. 410 00:20:35,110 --> 00:20:38,240 U nixtieq li inti tipprova u figura barra dak li suppost tagħmel. 411 00:20:38,240 --> 00:20:49,740 412 00:20:49,740 --> 00:20:52,480 >> Hekk meta wieħed iqis that-- tieħu minuta jew hekk. 413 00:20:52,480 --> 00:20:54,440 Ipprova u ċifra barra dak li għaddej hawn. 414 00:20:54,440 --> 00:21:58,840 415 00:21:58,840 --> 00:21:59,570 >> Xi ideat? 416 00:21:59,570 --> 00:22:08,180 417 00:22:08,180 --> 00:22:12,470 >> Aħna nafu li aħna jkollu almenu tnejn argumenti kmand tal-linja, id-dritt? 418 00:22:12,470 --> 00:22:16,270 I jassumi li waħda minnhom se tkun li [inaudible] tal-programm tagħna huwa 419 00:22:16,270 --> 00:22:17,530 u mbagħad xi ħaġa oħra. 420 00:22:17,530 --> 00:22:19,980 Għaliex jekk [inaudible] huwa inqas minn tnejn, aħna Yell fil minnhom. 421 00:22:19,980 --> 00:22:21,140 Dritt? 422 00:22:21,140 --> 00:22:25,300 U mill-użu, jidher qisu li għaddej biex tkun xi tip ta 'fajl. 423 00:22:25,300 --> 00:22:26,260 Aħna kollha jaqblu ma 'dik? 424 00:22:26,260 --> 00:22:29,110 425 00:22:29,110 --> 00:22:31,570 Allura issa, x'inhu l-linja tagħmel? 426 00:22:31,570 --> 00:22:32,570 X'hemm dan għaddejjin? 427 00:22:32,570 --> 00:22:35,000 428 00:22:35,000 --> 00:22:36,449 >> UDJENZA: Il-fajls kollha. 429 00:22:36,449 --> 00:22:37,240 SPEAKER 1: Eżattament. 430 00:22:37,240 --> 00:22:39,650 Li għaddej kollha permezz tal- fajls li Imxejna input hemmhekk. 431 00:22:39,650 --> 00:22:40,720 432 00:22:40,720 --> 00:22:46,040 Allura għal kull fajl, huwa ftuħ xi sekwenza hemmhekk. 433 00:22:46,040 --> 00:22:47,560 Huwa ftuħ dan il-fajl. 434 00:22:47,560 --> 00:22:48,060 Dritt? 435 00:22:48,060 --> 00:22:49,140 436 00:22:49,140 --> 00:22:52,380 U huwa qari minnha. 437 00:22:52,380 --> 00:22:53,420 438 00:22:53,420 --> 00:22:55,540 Of course, iċċekkjar jekk huwa null. 439 00:22:55,540 --> 00:22:57,220 U allura huwa istampar. 440 00:22:57,220 --> 00:23:01,460 Jekk huwa null, huwa biss tgħidilna li li mhux fajl li teżisti. 441 00:23:01,460 --> 00:23:04,290 Minħabba ftakar, ma aqra fajl tagħna għandu jeżisti. 442 00:23:04,290 --> 00:23:04,810 Dritt? 443 00:23:04,810 --> 00:23:06,870 Bil jiktbu u tehmeż, inti tista 'tikseb bogħod magħha. 444 00:23:06,870 --> 00:23:08,970 Iżda ma jaqra, fajl tagħna għandu jeżisti. 445 00:23:08,970 --> 00:23:10,430 446 00:23:10,430 --> 00:23:13,330 >> U mbagħad jekk ma jeżistix, dak li aħna tagħmel hawn? 447 00:23:13,330 --> 00:23:14,810 448 00:23:14,810 --> 00:23:15,780 Ejja biss tibda hawn. 449 00:23:15,780 --> 00:23:18,815 X'hemm dan do-- din l-ewwel karattru. 450 00:23:18,815 --> 00:23:20,960 451 00:23:20,960 --> 00:23:21,790 X'tikkontrolla do? 452 00:23:21,790 --> 00:23:24,100 He gets karattru wieħed, id-dritt? 453 00:23:24,100 --> 00:23:25,400 Allura dak li huwa dan isir? 454 00:23:25,400 --> 00:23:26,775 Huwa jkollna l-ewwel karattru. 455 00:23:26,775 --> 00:23:28,860 456 00:23:28,860 --> 00:23:30,200 Xi ħadd jaf EOF? 457 00:23:30,200 --> 00:23:31,170 >> UDJENZA: Tmiem tal-fajl? 458 00:23:31,170 --> 00:23:32,680 >> SPEAKER 1: Tmiem ta file-- eżattament. 459 00:23:32,680 --> 00:23:35,310 Allura li għaddej biex jgħaddu il-fajl kollu, id-dritt? 460 00:23:35,310 --> 00:23:36,710 461 00:23:36,710 --> 00:23:40,780 U allura li għaddej biex taġġorna minn jkollna kull karattru sussegwenti. 462 00:23:40,780 --> 00:23:41,565 Dritt? 463 00:23:41,565 --> 00:23:43,636 U x'hemm dan isir? 464 00:23:43,636 --> 00:23:44,760 UDJENZA: Inpoġġu li in-- 465 00:23:44,760 --> 00:23:46,741 466 00:23:46,741 --> 00:23:49,170 >> SPEAKER 1: Putchar prints li Screensaver tiegħek. 467 00:23:49,170 --> 00:23:50,867 468 00:23:50,867 --> 00:23:51,950 [Inaudible]-karattru. 469 00:23:51,950 --> 00:23:54,300 U mbagħad meta [inaudible] dan se tagħlaq il-fajl. 470 00:23:54,300 --> 00:23:57,370 >> UDJENZA: Inti ma bżonn ta '[? ieħor? ?] 471 00:23:57,370 --> 00:23:59,005 >> SPEAKER 1: Mhux bilfors. 472 00:23:59,005 --> 00:24:01,480 I mean, huwa tip ta 'implikat f'dan. 473 00:24:01,480 --> 00:24:06,780 Minħabba dan prospetti, għalkemm, sakemm dan ma qabda dan, int multa. 474 00:24:06,780 --> 00:24:07,940 475 00:24:07,940 --> 00:24:10,250 I jfissirx li huwa probabbilment tajjeb prattika li tagħmel ħaġa oħra. 476 00:24:10,250 --> 00:24:15,755 Iżda inkella mhux dejjem meħtieġ speċjalment 477 00:24:15,755 --> 00:24:17,610 jekk għandek xi ħaġa bħal ritorn, li 478 00:24:17,610 --> 00:24:20,640 ifisser li f'dan il-każ jekk il-qabdiet dan, program tiegħek ser jispiċċaw 479 00:24:20,640 --> 00:24:21,850 u qatt ser tikseb dan. 480 00:24:21,850 --> 00:24:23,030 481 00:24:23,030 --> 00:24:29,190 Huwa aktar għall-każ fejn int mhux neċessarjament jirritornaw xi ħaġa. 482 00:24:29,190 --> 00:24:31,370 Għaliex jekk dan ma kienx jirritornaw xejn, 483 00:24:31,370 --> 00:24:34,430 dan ikun ifisser li jekk dan kien minnu, il-bqija ta 'dan xorta run. 484 00:24:34,430 --> 00:24:36,138 U f'dak il-każ, inti tkunx tixtieq falza. 485 00:24:36,138 --> 00:24:38,240 Jekk huwa jirritorna, u tmiem il-programm tiegħek, 486 00:24:38,240 --> 00:24:41,960 l inkella mhux meħtieġ kollu il-ħin, jiddependi fuq il-kuntest. 487 00:24:41,960 --> 00:24:43,084 488 00:24:43,084 --> 00:24:44,375 Jacob, ma għandek xi mistoqsija? 489 00:24:44,375 --> 00:24:46,100 UDJENZA: Yeah. 490 00:24:46,100 --> 00:24:49,300 Allura ma fgetc jiksbu l-karattru li jmiss? 491 00:24:49,300 --> 00:24:50,734 Kif ma jżid il-karattru? 492 00:24:50,734 --> 00:24:51,400 SPEAKER 1: Yeah. 493 00:24:51,400 --> 00:24:52,774 Allura fgetc gets-karattru li jmiss. 494 00:24:52,774 --> 00:24:54,140 495 00:24:54,140 --> 00:24:56,866 Inti tista 'taħseb hija simili C ++ f'sens. 496 00:24:56,866 --> 00:24:58,350 >> UDJENZA: Allura dak li kien EOF? 497 00:24:58,350 --> 00:25:00,877 >> SPEAKER 1: EOF hi l-aħħar tal-fajl. 498 00:25:00,877 --> 00:25:03,960 Huwa biss markatur li ihallik taf li int fl-aħħar tal-fajl tiegħek. 499 00:25:03,960 --> 00:25:06,742 Allura dan se jistampaw biex tiegħek standard out. 500 00:25:06,742 --> 00:25:08,950 U allura li għaddej biex tagħlaq il-fajl meta dan isir. 501 00:25:08,950 --> 00:25:10,700 U mbagħad ejja mur il-fajl li jmiss, id-dritt? 502 00:25:10,700 --> 00:25:12,660 Allura ġenerali, dak ma dan il-programm do? 503 00:25:12,660 --> 00:25:15,402 504 00:25:15,402 --> 00:25:16,090 >> [Inaudible] 505 00:25:16,090 --> 00:25:16,900 >> SPEAKER 1: Yeah. 506 00:25:16,900 --> 00:25:18,770 Hija biss prints out kollox hemm. 507 00:25:18,770 --> 00:25:23,270 Mela CAT jekk inti guys qatt jintużaw u mbagħad l-isem ta 'xi file-- 508 00:25:23,270 --> 00:25:26,240 I do not know jekk kwalunkwe inti għandek qatt sar li fuq tagħmir terminali tiegħek. 509 00:25:26,240 --> 00:25:29,630 Imma jekk inti qatt tuża l- kmand CAT-- C-A-T-- 510 00:25:29,630 --> 00:25:31,880 u mbagħad ikun x'ikun fajl ikollok there-- dan 511 00:25:31,880 --> 00:25:37,260 prints out għal terminali tiegħek, li jista 'jkun super handy għal xi affarijiet. 512 00:25:37,260 --> 00:25:38,746 I użu ħafna. 513 00:25:38,746 --> 00:25:40,120 Ma li jagħmel sens għal kulħadd? 514 00:25:40,120 --> 00:25:41,480 515 00:25:41,480 --> 00:25:42,100 Kessaħ? 516 00:25:42,100 --> 00:25:46,530 >> OK hekk kompitu tiegħek now-- jew billi lilek innifsek jew mal-poplu madwar you-- 517 00:25:46,530 --> 00:25:54,930 huwa biss jiktbu program sempliċi li se biss jiktbu "Hello, dinja!" 518 00:25:54,930 --> 00:25:56,255 out għal fajl. 519 00:25:56,255 --> 00:26:00,215 >> [Inaudible] 520 00:26:00,215 --> 00:26:56,210 521 00:26:56,210 --> 00:26:57,040 >> [Inaudible] 522 00:26:57,040 --> 00:26:59,248 >> SPEAKER 1: I kien simili, ma I do dan ħażin ġimgħa li għaddiet? 523 00:26:59,248 --> 00:27:00,201 524 00:27:00,201 --> 00:27:01,492 Jien ma naħsibx li kien dik ħażina. 525 00:27:01,492 --> 00:27:02,479 526 00:27:02,479 --> 00:27:03,520 Ninsab kuntenta li inti qed kollha hawn. 527 00:27:03,520 --> 00:27:04,655 Huwa verament jagħmel me happy. 528 00:27:04,655 --> 00:27:07,565 529 00:27:07,565 --> 00:27:10,160 I'ma girl pjaċiri sempliċi. 530 00:27:10,160 --> 00:27:11,688 I biss nixtieq meta sezzjoni tiegħi jattendi. 531 00:27:11,688 --> 00:27:13,830 532 00:27:13,830 --> 00:27:18,270 Hekk jien biss jkollna dan beda għall inti guys sabiex inkunu nistgħu kodiċi flimkien. 533 00:27:18,270 --> 00:27:22,290 I ma simili tqegħid xi ħadd fuq il-post jekk inti tixtieq li tkun. 534 00:27:22,290 --> 00:27:26,486 535 00:27:26,486 --> 00:27:30,086 >> UDJENZA: Għall-kwizz, tagħmel għandna jiktbu program? 536 00:27:30,086 --> 00:27:33,260 >> SPEAKER 1: Inti tista 'tintalab biex jiktbu programmi sempliċi bl-idejn. 537 00:27:33,260 --> 00:27:35,940 538 00:27:35,940 --> 00:27:36,590 Yup. 539 00:27:36,590 --> 00:27:38,510 >> UDJENZA: Il-kwiżż huwa ġimgħa d-dieħla, id-dritt? 540 00:27:38,510 --> 00:27:40,108 >> SPEAKER 1: Il-kwiżż huwa l-Erbgħa li jmiss. 541 00:27:40,108 --> 00:27:40,855 542 00:27:40,855 --> 00:27:43,730 Dan ifisser hemm [sabiħ? CSE?] gradazzjoni partit wara, li 543 00:27:43,730 --> 00:27:50,390 ifisser li inti ser tingħata punteġġi tiegħek lura li night-- f'liema ħin? 544 00:27:50,390 --> 00:27:50,890 Min jaf? 545 00:27:50,890 --> 00:27:51,973 Iżda se jkun li bil-lejl. 546 00:27:51,973 --> 00:28:02,020 547 00:28:02,020 --> 00:28:02,855 >> Kull dritt. 548 00:28:02,855 --> 00:28:04,250 Kif irridu li tibda dan? 549 00:28:04,250 --> 00:28:07,964 550 00:28:07,964 --> 00:28:09,630 I ser jagħtuk jibda hint-- ma 'dan. 551 00:28:09,630 --> 00:28:11,455 >> UDJENZA: Inti għandek biex tiftaħ fajl. 552 00:28:11,455 --> 00:28:12,250 >> SPEAKER 1: Yeah. 553 00:28:12,250 --> 00:28:14,060 Allura dak li tridu li jsejħu dan? 554 00:28:14,060 --> 00:28:16,150 Do inti biss tixtieq li hija sejħa "fajl"? 555 00:28:16,150 --> 00:28:17,480 Ejjew nagħmluha faċli. 556 00:28:17,480 --> 00:28:26,752 Allura fopen-- x'hemm tagħna test output se tkun? 557 00:28:26,752 --> 00:28:36,130 Sejħa hija "Hello." 558 00:28:36,130 --> 00:28:37,810 U dak li huwa mod tagħna? 559 00:28:37,810 --> 00:28:39,764 560 00:28:39,764 --> 00:28:41,055 Liema huma aħna nagħmlu dan il-fajl? 561 00:28:41,055 --> 00:28:42,676 562 00:28:42,676 --> 00:28:43,500 >> UDJENZA: Aqra. 563 00:28:43,500 --> 00:28:44,401 564 00:28:44,401 --> 00:28:44,900 Kitba. 565 00:28:44,900 --> 00:28:46,191 SPEAKER 1: Aħna qed miktub lilha. 566 00:28:46,191 --> 00:28:47,360 567 00:28:47,360 --> 00:28:47,860 Sabiħ. 568 00:28:47,860 --> 00:28:50,330 569 00:28:50,330 --> 00:28:52,860 OK, hekk aħna dan il-fajl issa. 570 00:28:52,860 --> 00:28:54,920 571 00:28:54,920 --> 00:28:56,212 What do we bżonn tagħmel? 572 00:28:56,212 --> 00:28:57,420 UDJENZA: Iċċekkja jekk huwa null. 573 00:28:57,420 --> 00:28:59,820 SPEAKER 1: Iċċekkja jekk huwa null-- eżattament. 574 00:28:59,820 --> 00:29:01,980 Dan huwa dak I simili biex tisma. 575 00:29:01,980 --> 00:29:05,930 Li għandu jkun awtomatiku, speċjalment pretty ħafna minn dan il-punt fuq. 576 00:29:05,930 --> 00:29:07,530 577 00:29:07,530 --> 00:29:10,950 Jekk tibda segfaulting, inti probabilment ma jikkontrolla għal null x'imkien. 578 00:29:10,950 --> 00:29:12,480 Disa 'darbiet minn għaxar, li l- se tkun żball tiegħek. 579 00:29:12,480 --> 00:29:15,400 Hekk jekk inti tista 'biss tikseb fil- vizzju, dejjem iċċekkja jekk huwa null, 580 00:29:15,400 --> 00:29:18,150 ħajja tiegħek li għaddej biex tkun sbieħ u easy-- jew aktar faċli. 581 00:29:18,150 --> 00:29:19,480 >> Allura tikkontrolla biex tara jekk huwa null. 582 00:29:19,480 --> 00:29:21,200 583 00:29:21,200 --> 00:29:24,820 Mela jekk mhuwiex null, li huwa dak li l-bang ugwali 584 00:29:24,820 --> 00:29:26,784 means-- ma null-- huwa validu. 585 00:29:26,784 --> 00:29:27,700 What do rridu nagħmlu? 586 00:29:27,700 --> 00:29:29,750 587 00:29:29,750 --> 00:29:31,570 Aħna biss tixtieq li jistampaw għal dan il-fajl, id-dritt? 588 00:29:31,570 --> 00:29:32,923 Allura dak li aħna ser tuża? 589 00:29:32,923 --> 00:29:34,092 >> UDJENZA: Fprintf 590 00:29:34,092 --> 00:29:36,800 >> SPEAKER 1: Fprintf-- sabiħ. 591 00:29:36,800 --> 00:29:38,150 592 00:29:38,150 --> 00:29:44,000 U fprintf jieħu żewġ arguments-- fejn li għaddej u dak li rridu stampati. 593 00:29:44,000 --> 00:29:45,820 Allura x'inhu l-ewwel wieħed? 594 00:29:45,820 --> 00:29:46,570 Fejn huwa se? 595 00:29:46,570 --> 00:29:47,490 >> UDJENZA: File. 596 00:29:47,490 --> 00:29:48,785 >> SPEAKER 1: Huwa ser fajl. 597 00:29:48,785 --> 00:29:49,784 598 00:29:49,784 --> 00:29:50,950 U dak li rridu stampati? 599 00:29:50,950 --> 00:29:52,900 600 00:29:52,900 --> 00:29:58,065 "Hello, dinja!" 601 00:29:58,065 --> 00:29:58,565 Kull dritt. 602 00:29:58,565 --> 00:30:03,670 Aħna għandna l-aħħar thing-- wieħed ieħor paradigma kbira hawn. 603 00:30:03,670 --> 00:30:04,479 604 00:30:04,479 --> 00:30:05,145 UDJENZA: Agħlaq. 605 00:30:05,145 --> 00:30:05,853 SPEAKER 1: Agħlaq. 606 00:30:05,853 --> 00:30:09,990 607 00:30:09,990 --> 00:30:10,540 Hemm inti tmur. 608 00:30:10,540 --> 00:30:13,384 >> UDJENZA: Huwa dan jiġri jekk il-fajl huwa null? 609 00:30:13,384 --> 00:30:15,050 SPEAKER 1: Le, dan huwa jekk mhuwiex null. 610 00:30:15,050 --> 00:30:16,881 UDJENZA: Oh, jekk huwa not-- OK. 611 00:30:16,881 --> 00:30:21,728 612 00:30:21,728 --> 00:30:25,410 Għall-fopen u allura l- żewġ argumenti li jmorru ġewwa, 613 00:30:25,410 --> 00:30:27,655 dak ma l-ewwel argument ifisser mill-ġdid? 614 00:30:27,655 --> 00:30:30,392 >> SPEAKER 1: L-argument huwa bħall-isem tal-fajl 615 00:30:30,392 --> 00:30:31,350 li inti tixtieq li tmur. 616 00:30:31,350 --> 00:30:36,020 Hekk wara dan imur, inti jkollhom xi fajl imsejħa "bonjour" 617 00:30:36,020 --> 00:30:38,320 li kienet "Hello, dinja" fi ħdanu. 618 00:30:38,320 --> 00:30:38,820 Li kollox. 619 00:30:38,820 --> 00:30:39,500 Biss l-isem. 620 00:30:39,500 --> 00:30:42,685 621 00:30:42,685 --> 00:30:48,650 >> UDJENZA: U peress li huwa miktub, il- fajl ma jkollhom diġà jeżistu. 622 00:30:48,650 --> 00:30:49,675 Hija li dak li qal? 623 00:30:49,675 --> 00:30:50,410 >> SPEAKER 1: Dritt. 624 00:30:50,410 --> 00:30:50,910 Eżattament. 625 00:30:50,910 --> 00:30:53,110 626 00:30:53,110 --> 00:30:55,839 Jekk "Hello" bħala fajl s'issa ma jeżistix, huwa 627 00:30:55,839 --> 00:30:58,380 se toħloq fajl msejħa Hello "u jikteb lill dan għalik. 628 00:30:58,380 --> 00:30:59,631 629 00:30:59,631 --> 00:31:03,610 >> UDJENZA: Meta inti qed javżak il-programm li kiteb għall-fajl, 630 00:31:03,610 --> 00:31:08,075 għaliex tikteb "fajl" minflok l-isem tal-fajl u fprintf-- 631 00:31:08,075 --> 00:31:13,600 >> SPEAKER 1: Minħabba f'dan il-każ, għandna li FILE-- kbar kollha star caps--, 632 00:31:13,600 --> 00:31:14,260 fajl. 633 00:31:14,260 --> 00:31:17,370 Allura huwa pointer għall-fajl li qed jitkellem dwar. 634 00:31:17,370 --> 00:31:19,930 Dan huwa l-mod li aħna biss jirreferu għaliha. 635 00:31:19,930 --> 00:31:24,850 Allura f'dan il-każ, inti jistgħu jaħsbu Ah file--, 636 00:31:24,850 --> 00:31:31,271 nistgħu nużaw this-- fajl hawn jirreferi għall-ftuħ ta '"Hello" 637 00:31:31,271 --> 00:31:32,145 u kiri li jiktbu. 638 00:31:32,145 --> 00:31:34,728 >> UDJENZA: Jista npoġġux "Hello" minflok [? ta 'ftit?] f file? 639 00:31:34,728 --> 00:31:40,160 SPEAKER 1: Le, għaliex "Hello" jeħtieġ li jkun miftuħ u writeable. 640 00:31:40,160 --> 00:31:41,820 641 00:31:41,820 --> 00:31:45,980 File hawnhekk huwa bħal designator li tgħid OK, aħna 642 00:31:45,980 --> 00:31:49,190 jkollhom din hello-- file-- li aħna qed tħares lejn. 643 00:31:49,190 --> 00:31:50,680 Hija tkun infetħet. 644 00:31:50,680 --> 00:31:52,140 U aħna qed tmur biex jiktbu lilha. 645 00:31:52,140 --> 00:31:55,130 Jekk inti biss użu "Hello", li huwa inkapsulati fl dan. 646 00:31:55,130 --> 00:31:56,846 Allura li għaddej biex skerz. 647 00:31:56,846 --> 00:31:58,590 648 00:31:58,590 --> 00:32:00,300 I mean, inti jista 'jkun jismu dan. 649 00:32:00,300 --> 00:32:03,960 Li seta 'jsir il-fajl, star, "Hello", huwa egwali għal dak. 650 00:32:03,960 --> 00:32:07,840 Imma l-punt kollu huwa li inti bżonn pointer fajl stilla sabiex 651 00:32:07,840 --> 00:32:09,281 li tkun tista 'tuża dawn il-funzjonijiet. 652 00:32:09,281 --> 00:32:11,280 UDJENZA: Tista 'tagħmel fajl, star, fajl, "Hello" 653 00:32:11,280 --> 00:32:13,113 jew għandek tpoġġi fajl star, fajl minnha? 654 00:32:13,113 --> 00:32:16,330 SPEAKER 1: Inti tista ' do fajl, star, "Hello." 655 00:32:16,330 --> 00:32:19,790 Tista 'tbiddel dan kwalunkwe isem li trid. 656 00:32:19,790 --> 00:32:22,114 Huwa kompletament arbitrarju dak li l-isem huwa. 657 00:32:22,114 --> 00:32:23,179 658 00:32:23,179 --> 00:32:24,220 Tista 'isem li bih xejn. 659 00:32:24,220 --> 00:32:25,501 660 00:32:25,501 --> 00:32:28,020 Isem li bih jtajru spagetti, jekk int riedu. 661 00:32:28,020 --> 00:32:29,690 >> UDJENZA: X'inhi l- "w" fil-kwotazzjonijiet għall? 662 00:32:29,690 --> 00:32:31,540 >> SPEAKER 1: Il- "w" huwa biss il-mod. 663 00:32:31,540 --> 00:32:33,170 Allura aħna qed miktub lill dan il-fajl. 664 00:32:33,170 --> 00:32:34,410 665 00:32:34,410 --> 00:32:35,320 Kulħadd tajba? 666 00:32:35,320 --> 00:32:36,227 Ċara? 667 00:32:36,227 --> 00:32:36,981 Iva. 668 00:32:36,981 --> 00:32:40,365 >> UDJENZA: Allura meta jikteb dan fajl, fejn do we mbagħad isibu dan il-fajl? 669 00:32:40,365 --> 00:32:43,820 >> SPEAKER 1: Huwa ser jiġi fl-istess direttorju li int bħalissa. 670 00:32:43,820 --> 00:32:45,650 671 00:32:45,650 --> 00:32:48,880 Jekk int fil pset tlieta u inti tmexxi dan, fi ħdan pset tiegħek 672 00:32:48,880 --> 00:32:52,600 tliet folder se tkun dan il-fajl imsejħa "Hello." 673 00:32:52,600 --> 00:32:53,160 Kessaħ? 674 00:32:53,160 --> 00:32:53,757 Kulħadd tajba? 675 00:32:53,757 --> 00:32:55,840 Inħoss bħal int kollha jkollna, li hija kbira. 676 00:32:55,840 --> 00:32:57,290 677 00:32:57,290 --> 00:32:57,790 OK. 678 00:32:57,790 --> 00:33:05,960 Allura lura għall show-- slide tiegħi I love meta jaħdmu l-affarijiet. 679 00:33:05,960 --> 00:33:08,674 OK, pointers-- Are You guys eċċitati? 680 00:33:08,674 --> 00:33:09,465 Pointers huma kbar. 681 00:33:09,465 --> 00:33:11,581 682 00:33:11,581 --> 00:33:13,580 Huma jieħdu ftit biex nagħlaq ras tiegħek madwar. 683 00:33:13,580 --> 00:33:15,288 Dan huwa t-tieni sena tiegħi tagħlim pointers. 684 00:33:15,288 --> 00:33:16,850 U naħseb I finalment ltqajna. 685 00:33:16,850 --> 00:33:18,650 Mela jekk inti ibatu, huwa OK. 686 00:33:18,650 --> 00:33:19,940 687 00:33:19,940 --> 00:33:24,070 Kif għidt qabel, tpinġija stampi jgħin ħafna ma 'affarijiet fil-CS, 688 00:33:24,070 --> 00:33:27,400 kemm I think nies għandhom tendenza biex jaħsbu oh, aħna qed fuq kompjuter. 689 00:33:27,400 --> 00:33:28,399 Għandna biss kodiċi. 690 00:33:28,399 --> 00:33:30,190 No-- stampi tpinġija se verament tgħinek. 691 00:33:30,190 --> 00:33:32,773 And I really ninkoraġġukom biex vit fis-ġenb kindergartner tiegħek 692 00:33:32,773 --> 00:33:35,010 u jġibu l krejons jew markers u tiġbed. 693 00:33:35,010 --> 00:33:36,110 Minħabba li se jgħinek. 694 00:33:36,110 --> 00:33:39,380 U jekk inti tara lili fil-ħinijiet tal-uffiċċju, I se jkunu qed iġorru madwar munzelli tal-karta 695 00:33:39,380 --> 00:33:41,580 bil pinen tpinġija affarijiet out. 696 00:33:41,580 --> 00:33:44,370 >> Allura speċjalment ma pointers-- tiġbed ritratti. 697 00:33:44,370 --> 00:33:47,970 U jien ċert li aħna qed attwalment għaddejjin biex jkun tpinġija xi ritratti hawnhekk ukoll. 698 00:33:47,970 --> 00:33:51,270 >> Allura inti guys kollha ltqajna biex tara Binky, dan il-ħaġa claymation jibred. 699 00:33:51,270 --> 00:33:54,720 U naħsbu huwa verament umoristiċi meta hu tisplodi fi mazz ta 'biċċiet. 700 00:33:54,720 --> 00:33:56,280 701 00:33:56,280 --> 00:33:57,755 Huwa xi eżenzjoni komiks għall-klassi. 702 00:33:57,755 --> 00:34:02,140 703 00:34:02,140 --> 00:34:05,900 C [inaudible] din il-ħila kbira li tkun kapaċi biex jikkontrollaw memorja. 704 00:34:05,900 --> 00:34:10,090 U hija waħda mill-affarijiet li verament li jagħmilha tali lingwa qawwija. 705 00:34:10,090 --> 00:34:13,469 Imma bil-qawwa kbira tiġi responsabbiltà kbira. 706 00:34:13,469 --> 00:34:16,230 U l-affarijiet crazy jista 'jiġri jekk int ma attenta. 707 00:34:16,230 --> 00:34:18,560 Allura meta inti qed tuża pointers, inti tixtieq li tagħmel 708 00:34:18,560 --> 00:34:21,440 żgur li int verament jifhem eżattament dak li qed tagħmel. 709 00:34:21,440 --> 00:34:25,530 Nisperaw li l-ftit li jmiss ta ' żmien se jgħinek verament jifhem 710 00:34:25,530 --> 00:34:27,850 pointers, kif jużawhom, u kif jimmanipula lilhom. 711 00:34:27,850 --> 00:34:29,170 712 00:34:29,170 --> 00:34:33,460 >> So memory-- Jien ċert konna rajt dan dijagramma qabel. 713 00:34:33,460 --> 00:34:38,540 Allura din hija biss dijagramma sempliċi ta ' kif l-affarijiet jista 'jkun maħżun memorja. 714 00:34:38,540 --> 00:34:43,145 Allura inti bażikament jkollhom dawn arrays enormi ta 'blokki byte wieħed 715 00:34:43,145 --> 00:34:46,000 huwa dak li għandna here-- żgħir inkrementi minn wieħed kull darba. 716 00:34:46,000 --> 00:34:51,810 Dan huwa fil-hex [inaudible] hekk blokki tmien bit. 717 00:34:51,810 --> 00:34:55,510 U kull blokk huwa assoċjat ma 'xi indirizz hexadeċimali. 718 00:34:55,510 --> 00:34:58,750 Mela jekk inti qatt tara l- 0x, li jinsab biss notating 719 00:34:58,750 --> 00:35:00,670 li huwa indirizz hexadeċimali. 720 00:35:00,670 --> 00:35:03,970 Inti tista 'tassumi dan ifisser xi indirizz fil-memorja. 721 00:35:03,970 --> 00:35:06,935 Aħna qed jitkellem dwar l-indirizzi tal-memorja kull meta inti tara hexadeċimali. 722 00:35:06,935 --> 00:35:10,420 723 00:35:10,420 --> 00:35:14,630 >> Għandna ints huma varjabbli, sufruni huma varjabbli li jaħżnu. 724 00:35:14,630 --> 00:35:16,260 Allura ints ints maħżen. 725 00:35:16,260 --> 00:35:17,430 Maħżen sufruni sufruni. 726 00:35:17,430 --> 00:35:20,260 Allura irridu wkoll pointers li tindirizza taħżen memorja. 727 00:35:20,260 --> 00:35:21,660 C'est tip ta 'mapping. 728 00:35:21,660 --> 00:35:24,240 Pointers huma esklussivament għall-indirizzi memorja. 729 00:35:24,240 --> 00:35:25,780 730 00:35:25,780 --> 00:35:27,292 Allura dak simili tip tiegħek hemmhekk. 731 00:35:27,292 --> 00:35:29,550 732 00:35:29,550 --> 00:35:34,470 Appliance tiegħek huwa 32-bit, li jfisser li l-indirizz tal-memorja tiegħek huwa erba 'bytes. 733 00:35:34,470 --> 00:35:37,830 Sabiex kwalunkwe pointer li għandek huwa wkoll se jkun ta 'erba bytes. 734 00:35:37,830 --> 00:35:43,200 Jew inkella jekk huwa l-erba 'bytes, memorja huwa erba 'bytes. 735 00:35:43,200 --> 00:35:44,790 Memorja maħżen pointers. 736 00:35:44,790 --> 00:35:46,430 Għalhekk, dawn qed erba 'bytes. 737 00:35:46,430 --> 00:35:48,460 Cool-- biss trid tissaħħaħ dik. 738 00:35:48,460 --> 00:35:50,120 739 00:35:50,120 --> 00:35:52,220 >> Inti għandek tikseb dan komiks issa. 740 00:35:52,220 --> 00:35:55,040 I do not know kif ħafna minnkom huma fannijiet XKCD, imma I love XKCD. 741 00:35:55,040 --> 00:35:55,780 Huwa kbir. 742 00:35:55,780 --> 00:35:57,290 743 00:35:57,290 --> 00:35:57,790 >> Kull dritt. 744 00:35:57,790 --> 00:36:01,640 Allura ħolqien pointers-- kif għidt, huwa pretty ħafna biss bħal kull ħaġ'oħra. 745 00:36:01,640 --> 00:36:02,930 Għandek tip. 746 00:36:02,930 --> 00:36:04,050 Inti jkollha isem. 747 00:36:04,050 --> 00:36:04,810 Dritt? 748 00:36:04,810 --> 00:36:10,410 Dak hu li għandna hemmhekk. [? Hex?] Star ifisser li huwa pointer, 749 00:36:10,410 --> 00:36:12,250 u mbagħad tkun xi tkun tixtieq li hija sejħa. 750 00:36:12,250 --> 00:36:15,770 Allura l-tip jirrappreżenta dak li inti jista 'jaħżen. 751 00:36:15,770 --> 00:36:16,850 752 00:36:16,850 --> 00:36:17,990 Kull dritt? 753 00:36:17,990 --> 00:36:24,350 Bl-istess mod li jekk nagħmlu ints, nafu aħna qed ħażna ta int hemmhekk. 754 00:36:24,350 --> 00:36:25,990 755 00:36:25,990 --> 00:36:30,280 Bil-pointer, hija jkollha indirizz tal-memorja. 756 00:36:30,280 --> 00:36:34,240 Imma dak li jfisser hu that-- hawn fejn tpinġija se jidħlu fil handy. 757 00:36:34,240 --> 00:36:36,170 758 00:36:36,170 --> 00:36:45,980 Allura f'dan il-każ, għandna xi value-- ejja ngħidu erbgħa. 759 00:36:45,980 --> 00:36:49,306 Erba huwa fl-indirizz wieħed. 760 00:36:49,306 --> 00:36:49,805 OK? 761 00:36:49,805 --> 00:36:51,550 762 00:36:51,550 --> 00:36:56,170 >> Dan l-ewwel waħda hawnhekk tfisser li huwa 2x pointer. 763 00:36:56,170 --> 00:36:56,740 Dritt? 764 00:36:56,740 --> 00:36:57,628 Huwa xi pointer x. 765 00:36:57,628 --> 00:36:58,852 766 00:36:58,852 --> 00:37:00,940 x tistax tkun xi ħaġa, tkun xi tkun. 767 00:37:00,940 --> 00:37:01,960 768 00:37:01,960 --> 00:37:05,130 Tkun xi tkun x is-- jgħidu x huwa erbgħa. 769 00:37:05,130 --> 00:37:07,280 Li għaddej biex jaħżnu l- indirizz tal-memorja hawn. 770 00:37:07,280 --> 00:37:12,260 Allura int, star, x-- dan huwa xi slot oħra memory-- 771 00:37:12,260 --> 00:37:13,590 li jaf dak li din hija. 772 00:37:13,590 --> 00:37:15,430 Iżda li għaddej biex taħżen l-indirizz hawn. 773 00:37:15,430 --> 00:37:27,040 Għalhekk dan ikun like-- f'dan il-każ, Tkun xi tkun, 774 00:37:27,040 --> 00:37:32,630 hija maħżuna fil 0x1-- kollu li huwa maħżun fl-indirizz li pointer tagħna jkollha, 775 00:37:32,630 --> 00:37:35,280 irid ikun kompatibbli ma dak li konna nominati. 776 00:37:35,280 --> 00:37:40,330 Allura fil 0x1, f'dan il-każ, dan huwa x. 777 00:37:40,330 --> 00:37:42,500 778 00:37:42,500 --> 00:37:49,340 Dan jista 'biss qatt tkun int filwaqt li aħna qed jużaw dan. 779 00:37:49,340 --> 00:37:52,950 >> Bl-istess mod, jekk ikollna 1y ieħor, ikun x'ikun 780 00:37:52,950 --> 00:37:59,130 indirizz hija maħżuna ma 'y għandu li tkun istess ħaġa char-- ma z. 781 00:37:59,130 --> 00:38:05,840 Bl-istess mod, kull meta inti tipprova tagħmel intx ugwali 0.4, 782 00:38:05,840 --> 00:38:09,275 li għaddej biex Yell fi inti u tkun ebda simili, inti qal inti riedu int. 783 00:38:09,275 --> 00:38:10,525 Dan huwa suppost li tkun int. 784 00:38:10,525 --> 00:38:11,900 Tieqaf jippruvaw li jagħmilha float. 785 00:38:11,900 --> 00:38:14,150 >> So let affarijiet jkun dak li tixtieq li tkun. 786 00:38:14,150 --> 00:38:15,159 787 00:38:15,159 --> 00:38:16,200 Ħalli affarijiet jkun infushom. 788 00:38:16,200 --> 00:38:19,380 789 00:38:19,380 --> 00:38:23,450 Allura ħaġa kbira hija biss kwalunkwe tip ta 'pointer 790 00:38:23,450 --> 00:38:26,101 huwa, dak l-unika ħaġa li tista 'taħżen hemmhekk. 791 00:38:26,101 --> 00:38:26,600 OK? 792 00:38:26,600 --> 00:38:27,910 793 00:38:27,910 --> 00:38:31,160 Bil-prattika, kif ma ' aħħar ġimgħa, kollox 794 00:38:31,160 --> 00:38:32,817 jidher verament tip ta 'astratt. 795 00:38:32,817 --> 00:38:34,150 Aħna qed tmur biex tagħmel xi prattika. 796 00:38:34,150 --> 00:38:36,760 Hija għandha tagħmel aktar sens. 797 00:38:36,760 --> 00:38:44,580 >> Allura referenzjar u dereferencing-- huwa verament importanti li tikseb dawn dritta. 798 00:38:44,580 --> 00:38:46,630 I xorta jkollhom jġedded u mbagħad kull issa. 799 00:38:46,630 --> 00:38:48,450 U jien bħal stenna, liema waħda irrid? 800 00:38:48,450 --> 00:38:56,080 Allura l-ampersand fatt se tagħti inti ir-referenza jew l-indirizz ta '. 801 00:38:56,080 --> 00:39:00,100 Allura dan jirritorna l-indirizz fil- memorja ta 'liema varjabbli huwa maħżun. 802 00:39:00,100 --> 00:39:01,170 803 00:39:01,170 --> 00:39:07,020 Allura li għaddej biex attwalment jirritornaw lilek a hexadecimal, billi dereferencing dan 804 00:39:07,020 --> 00:39:10,641 huwa attwalment ser jagħtuk id-data li hija maħżuna hemmhekk. 805 00:39:10,641 --> 00:39:11,140 OK? 806 00:39:11,140 --> 00:39:12,680 807 00:39:12,680 --> 00:39:16,060 Allura aħna qed tmur biex tħares lejn eżempju verament mgħaġġel, jew attwalment up li jmiss. 808 00:39:16,060 --> 00:39:18,050 809 00:39:18,050 --> 00:39:19,150 >> OK. 810 00:39:19,150 --> 00:39:21,790 Allura aħna għandna biex jaħsbu verament sew dwar dan. 811 00:39:21,790 --> 00:39:23,860 Allura hawnhekk għandna xi integer x. 812 00:39:23,860 --> 00:39:26,485 Jien ser jippruvaw u tiġbed dan l-aħjar tal-kapaċitajiet tiegħi. 813 00:39:26,485 --> 00:39:30,230 814 00:39:30,230 --> 00:39:32,410 Allura aħna qed tmur li jkollhom din slot x. 815 00:39:32,410 --> 00:39:35,850 816 00:39:35,850 --> 00:39:37,315 U huwa ħażna ħamsa. 817 00:39:37,315 --> 00:39:38,640 818 00:39:38,640 --> 00:39:40,090 Indirizz tagħha huwa 0x4. 819 00:39:40,090 --> 00:39:41,920 820 00:39:41,920 --> 00:39:43,160 Kessaħ? 821 00:39:43,160 --> 00:39:44,100 Kollha tajba. 822 00:39:44,100 --> 00:39:45,470 >> Allura issa għandna dan il-werrej. 823 00:39:45,470 --> 00:39:46,916 824 00:39:46,916 --> 00:39:47,990 Kien minn hawn. 825 00:39:47,990 --> 00:39:52,130 826 00:39:52,130 --> 00:39:57,560 U l-ampersand tagħtina l-indirizz ta 'xi ħaġa. 827 00:39:57,560 --> 00:40:00,780 Allura, f'dan il-każ, huwa l-indirizz ta 'x. 828 00:40:00,780 --> 00:40:01,875 X'inhu l-indirizz ta 'x? 829 00:40:01,875 --> 00:40:05,660 830 00:40:05,660 --> 00:40:12,590 04-- u dan pointer huwa fil 0x08. 831 00:40:12,590 --> 00:40:14,490 832 00:40:14,490 --> 00:40:14,990 Kessaħ? 833 00:40:14,990 --> 00:40:16,570 834 00:40:16,570 --> 00:40:21,570 Allura inti tista 'taħseb dwar dan pointer, 04, ftit punti hawn fuq. 835 00:40:21,570 --> 00:40:22,840 836 00:40:22,840 --> 00:40:25,740 U dawn qed jissejjaħ pointers għaliex kif aħna nikseb aktar fis dan, 837 00:40:25,740 --> 00:40:28,450 int ser tara li tipponta lejn l-affarijiet. 838 00:40:28,450 --> 00:40:31,470 U blokka waħda tipponta għall-ieħor blokk se tagħmel ħafna aktar sens. 839 00:40:31,470 --> 00:40:32,760 840 00:40:32,760 --> 00:40:33,890 Allura hawnhekk huma tnejn. 841 00:40:33,890 --> 00:40:38,230 U allura aħna għandna xi kopja, li huwa 0x0c what--. 842 00:40:38,230 --> 00:40:41,290 843 00:40:41,290 --> 00:40:43,420 U li għaddej biex dereference pointer tagħna. 844 00:40:43,420 --> 00:40:46,790 >> Allura dak li kien qal huwa OK, hawnhekk pointer tagħna. 845 00:40:46,790 --> 00:40:53,090 Il-valur huwa jaħżen huwa 0x04, U liema huwa qal hu li tmur f'dan l-indirizz 846 00:40:53,090 --> 00:40:54,300 u tell me x'hemm fiha. 847 00:40:54,300 --> 00:40:55,520 848 00:40:55,520 --> 00:40:57,710 Allura dak effettivament dak li dan vleġġa qed tagħmel. 849 00:40:57,710 --> 00:40:58,750 850 00:40:58,750 --> 00:41:01,280 Inti tista 'taħseb dan bħal stilla tiegħek. 851 00:41:01,280 --> 00:41:05,410 Allura OK, meta nagħmlu star, dan ifisser isegwu. 852 00:41:05,410 --> 00:41:06,810 Mur dan l-indirizz. 853 00:41:06,810 --> 00:41:11,430 U dan huwa bażikament biss wara Din il-vleġġa għal din chunk memorja. 854 00:41:11,430 --> 00:41:15,380 U tagħtina x'hemm fiha, li hija ta '5. 855 00:41:15,380 --> 00:41:18,840 Huwa għalhekk li kopja tagħna huwa ugwali għal 5. 856 00:41:18,840 --> 00:41:20,120 Ma li jagħmel sens? 857 00:41:20,120 --> 00:41:22,769 Ħadd ma bżonn lili biex jgħaddu li għal darb'oħra, jew aktar bil-mod? 858 00:41:22,769 --> 00:41:24,560 Inti trid lili biex tmur permezz ta 'dan wieħed aktar ħin? 859 00:41:24,560 --> 00:41:25,060 OK. 860 00:41:25,060 --> 00:41:27,549 861 00:41:27,549 --> 00:41:28,840 Aħna qed tmur biex tiġbed mill-ġdid. 862 00:41:28,840 --> 00:41:31,930 863 00:41:31,930 --> 00:41:37,205 Meta nibdew, aħna kollha jaqblu li għandna xi blokki ta 'memorja li l-varjabbli 864 00:41:37,205 --> 00:41:40,890 x li waqqafna ugwali għal 5. 865 00:41:40,890 --> 00:41:42,910 Li aħna ma nikkontrollawhomx fejn huwa fl-memorja. 866 00:41:42,910 --> 00:41:45,520 Allura dan il-post huwa biss assenjat arbitrarjament. 867 00:41:45,520 --> 00:41:47,770 868 00:41:47,770 --> 00:41:48,731 Tajba hemmhekk? 869 00:41:48,731 --> 00:41:49,230 OK. 870 00:41:49,230 --> 00:41:50,420 871 00:41:50,420 --> 00:41:53,330 Imbagħad aħna initialize pointer għal int. 872 00:41:53,330 --> 00:41:56,900 C'est pourquoi huwa permess li jippuntaw lejn x għaliex għandna int fil hawn. 873 00:41:56,900 --> 00:42:00,840 Għandna blokki oħra ta ' memorja għaliex dan il-werrej 874 00:42:00,840 --> 00:42:03,485 hija varjabbli bħad kull ħaġ'oħra. 875 00:42:03,485 --> 00:42:06,615 Huwa assenjat arbitrarjament xi spazju fil-memorja. 876 00:42:06,615 --> 00:42:07,630 877 00:42:07,630 --> 00:42:10,830 U dak huwa jaħżen huwa l-indirizz ta 'x. 878 00:42:10,830 --> 00:42:13,200 Ampersand ifisser indirizz ta 'x. 879 00:42:13,200 --> 00:42:14,575 Allura x'inhi l-indirizz ta 'x? 880 00:42:14,575 --> 00:42:19,179 881 00:42:19,179 --> 00:42:20,614 >> UDJENZA: Huwa zero-- 882 00:42:20,614 --> 00:42:21,280 SPEAKER 1: 0x04. 883 00:42:21,280 --> 00:42:24,350 884 00:42:24,350 --> 00:42:25,940 Allura then-- aħħar wieħed. 885 00:42:25,940 --> 00:42:30,650 Għandna xi copy-- darb'oħra biss ieħor varjabbli. 886 00:42:30,650 --> 00:42:32,520 Mela ejja tassenja xi post arbitrarja. 887 00:42:32,520 --> 00:42:35,260 888 00:42:35,260 --> 00:42:38,080 U aħna dereference pointer tagħna. 889 00:42:38,080 --> 00:42:42,490 L-istilla ifisser jmorru għall- indirizz maħżuna fil pointer tiegħi. 890 00:42:42,490 --> 00:42:44,480 Tell me x'hemm hemmhekk. 891 00:42:44,480 --> 00:42:47,290 Allura l-indirizz maħżuna fil pointer tagħna huwa 0x04. 892 00:42:47,290 --> 00:42:49,070 893 00:42:49,070 --> 00:42:51,310 Allura aħna tmur f'dak l-indirizz. 894 00:42:51,310 --> 00:42:52,402 895 00:42:52,402 --> 00:42:54,590 Huwa tipponta lejn dak l-indirizz. 896 00:42:54,590 --> 00:42:57,481 X'hemm ġewwa din il-blokka tal-memorja? 897 00:42:57,481 --> 00:42:57,980 Huwa ħamsa. 898 00:42:57,980 --> 00:42:59,210 899 00:42:59,210 --> 00:43:01,650 Allura dak hu li aħna tassenja kopja tagħna. 900 00:43:01,650 --> 00:43:03,430 901 00:43:03,430 --> 00:43:04,860 Kulħadd tajba? 902 00:43:04,860 --> 00:43:05,360 Kessaħ. 903 00:43:05,360 --> 00:43:07,010 904 00:43:07,010 --> 00:43:08,330 Stampi Again--. 905 00:43:08,330 --> 00:43:19,750 906 00:43:19,750 --> 00:43:25,200 >> Allura tracking l-valuri here-- jien ser let inti guys jaħsbu dwar dan. 907 00:43:25,200 --> 00:43:26,550 908 00:43:26,550 --> 00:43:27,750 Nistgħu nużaw ieħor stampa. 909 00:43:27,750 --> 00:43:31,260 Imma nixtieq li inti tipprova u r-raġuni permezz ta 'dan fuq tiegħek għal minuta. 910 00:43:31,260 --> 00:44:01,430 911 00:44:01,430 --> 00:44:04,149 >> Billi dawn ma kinux jagħtu us indirizz eżempju, 912 00:44:04,149 --> 00:44:06,940 Jien biss se jagħmlu x-- ampersand li għandu jgħin issuq dar. 913 00:44:06,940 --> 00:44:07,950 Ampersand ifisser indirizz. 914 00:44:07,950 --> 00:44:09,540 915 00:44:09,540 --> 00:44:12,360 >> Hekk fl-ewwel waħda, kulħadd jmorru ma 'l-ewwel linja. 916 00:44:12,360 --> 00:44:15,690 Xi x sett ta five-- xi slot każwali fil-memorja. 917 00:44:15,690 --> 00:44:17,660 918 00:44:17,660 --> 00:44:23,200 Int pointer star hija ugwali fl-indirizz ta 'x, id-dritt? 919 00:44:23,200 --> 00:44:28,180 Int pointer star joħloq dan il-blokk, jitlob dan pointer, 920 00:44:28,180 --> 00:44:30,650 u tassenja lill-indirizz ta 'x. 921 00:44:30,650 --> 00:44:32,750 922 00:44:32,750 --> 00:44:34,230 Jien terribbli fil ampersands. 923 00:44:34,230 --> 00:44:36,460 924 00:44:36,460 --> 00:44:40,550 >> Issa dak li aħna qed tagħmel hija aħna ngħidu OK, dereference pointer tagħna. 925 00:44:40,550 --> 00:44:42,760 Allura immorru OK, x'hemm pointer tagħna? 926 00:44:42,760 --> 00:44:44,820 Huwa ampersand x. 927 00:44:44,820 --> 00:44:49,400 Mur ampersand x u jassenja mill-ġdid. 928 00:44:49,400 --> 00:44:51,620 929 00:44:51,620 --> 00:44:57,480 >> Allura issa, ampersand x se tkun 35. 930 00:44:57,480 --> 00:45:01,540 931 00:45:01,540 --> 00:45:05,174 Allura bażikament, meta int dereferencing, inti tmur OK. 932 00:45:05,174 --> 00:45:07,090 Int ser tkun tpinġija stampi bħal dan. 933 00:45:07,090 --> 00:45:09,423 Int ser tkun tpinġija vleġeġ tiegħek aktar minn fejn hu. 934 00:45:09,423 --> 00:45:16,030 Allura jmorru għal din slot fil-memorja u jew tagħti me dak il-valur lura, jew jibdlu dan. 935 00:45:16,030 --> 00:45:21,620 F'dan il-każ, għaliex aħna qed f'dan valur, aħna qed assenjazzjoni li jkun 35. 936 00:45:21,620 --> 00:45:24,700 Billi fl-aħħar wieħed, jekk tinnota, aħna 937 00:45:24,700 --> 00:45:27,680 kienu tassenja dak li kien fil hawn għal xi ħaġa oħra. 938 00:45:27,680 --> 00:45:30,450 939 00:45:30,450 --> 00:45:32,245 >> Allura dawn ikollhom din it-tabella tal-biża. 940 00:45:32,245 --> 00:45:35,000 941 00:45:35,000 --> 00:45:36,890 Huwa mhux ħażin. 942 00:45:36,890 --> 00:45:37,970 Inti guys jaħdmu fuqha. 943 00:45:37,970 --> 00:45:39,640 Jien ser tiġbed out fuq il-bord. 944 00:45:39,640 --> 00:45:41,306 Aħna qed tmur biex jimlew it out flimkien, OK? 945 00:45:41,306 --> 00:45:42,290 946 00:45:42,290 --> 00:45:45,530 Allura grab xi karta, grab sieħeb, tibda taħdem. 947 00:45:45,530 --> 00:45:53,897 948 00:45:53,897 --> 00:45:55,605 Jien ser tikseb biċċa akbar ta 'ġibs. 949 00:45:55,605 --> 00:45:56,624 950 00:45:56,624 --> 00:45:58,150 Minħabba li għaddej biex tkun ħafna. 951 00:45:58,150 --> 00:45:59,410 952 00:45:59,410 --> 00:45:59,910 OK. 953 00:45:59,910 --> 00:48:08,567 954 00:48:08,567 --> 00:48:09,150 PROFESSOR: OK. 955 00:48:09,150 --> 00:48:11,599 956 00:48:11,599 --> 00:48:12,890 Nibdew bl-ewwel ringiela. 957 00:48:12,890 --> 00:48:14,070 958 00:48:14,070 --> 00:48:16,970 Aħna ser tibda hemmhekk, allura inti guys jistgħu forsi jaħdmu permezz ftit aktar. 959 00:48:16,970 --> 00:48:17,870 OK. 960 00:48:17,870 --> 00:48:19,810 a ugwali darbiet b c iva, liema huwa? 961 00:48:19,810 --> 00:48:21,420 962 00:48:21,420 --> 00:48:23,260 Mhuwiex mistoqsija trick, I wegħda. 963 00:48:23,260 --> 00:48:24,440 >> STUDENT: 4 darbiet 5. 964 00:48:24,440 --> 00:48:25,420 >> PROFESSOR: 4 darbiet 5. 965 00:48:25,420 --> 00:48:25,920 20. 966 00:48:25,920 --> 00:48:26,730 Allura x'hemm b? 967 00:48:26,730 --> 00:48:27,921 968 00:48:27,921 --> 00:48:28,420 STUDENT: 4. 969 00:48:28,420 --> 00:48:30,204 970 00:48:30,204 --> 00:48:31,043 >> PROFESSOR: U ċ? 971 00:48:31,043 --> 00:48:31,542 STUDENT: 5. 972 00:48:31,542 --> 00:48:32,083 PROFESSOR: 5. 973 00:48:32,083 --> 00:48:35,960 U allura dan huwa biss se jiġu ampersand a, ampersand b, 974 00:48:35,960 --> 00:48:38,575 ampersand c, id-dritt? 975 00:48:38,575 --> 00:48:39,728 976 00:48:39,728 --> 00:48:40,596 Mhux ħażin. 977 00:48:40,596 --> 00:48:42,081 Huwa sempliċi biżżejjed. 978 00:48:42,081 --> 00:48:42,580 OK. 979 00:48:42,580 --> 00:48:44,300 Allura dak li jmiss. 980 00:48:44,300 --> 00:48:48,725 A huwa ugwali għal darbiet c, fil-każ ħadd kienet familjari ma 'dak. 981 00:48:48,725 --> 00:48:49,812 982 00:48:49,812 --> 00:48:53,300 Huwa kulħadd familjari maż-żminijiet ugwali? 983 00:48:53,300 --> 00:49:00,105 OK, dan kollu means-- dan huwa shorthand għal huwa ugwali għal darbiet c. 984 00:49:00,105 --> 00:49:04,840 Inti tista 'ukoll tagħmel dan ma diviżjoni, bil Barra minn hekk, ma tnaqqis. 985 00:49:04,840 --> 00:49:12,130 Inti tista 'tagħmel ugwali, jew plus ugwali c tfisser ugwali plus c, nieqes ugwali 986 00:49:12,130 --> 00:49:15,190 c tkun ugwali għal minus c. 987 00:49:15,190 --> 00:49:16,690 Huwa biss zokkor sintattika. 988 00:49:16,690 --> 00:49:19,380 989 00:49:19,380 --> 00:49:24,140 >> Allura, f'dan il-każ, li huwa ugwali għal drabi c tagħtina dak? 990 00:49:24,140 --> 00:49:25,910 991 00:49:25,910 --> 00:49:28,186 Għal darb'oħra, mhix kwistjoni trick. 992 00:49:28,186 --> 00:49:28,965 >> STUDENT: 100. 993 00:49:28,965 --> 00:49:29,300 >> PROFESSOR: 100. 994 00:49:29,300 --> 00:49:30,383 Ma xi ħaġa oħra bidla? 995 00:49:30,383 --> 00:49:31,790 996 00:49:31,790 --> 00:49:32,290 No 997 00:49:32,290 --> 00:49:37,380 998 00:49:37,380 --> 00:49:39,850 Forsi I se finalment nikseb aħjar fil ampersands tiegħi. 999 00:49:39,850 --> 00:49:42,047 >> STUDENT: OK, sorry, kif ma ikollok 100? 1000 00:49:42,047 --> 00:49:42,630 PROFESSOR: OK. 1001 00:49:42,630 --> 00:49:46,594 Allura huwa ugwali għal darbiet c, hekk darbiet c. 1002 00:49:46,594 --> 00:49:48,510 STUDENT: Oh, inti qed tuża a għall-previous-- 1003 00:49:48,510 --> 00:49:49,135 PROFESSOR: Iva. 1004 00:49:49,135 --> 00:49:51,450 Allura dawn huma l-valuri l-aktar reċenti tagħna. 1005 00:49:51,450 --> 00:49:53,990 Dawn huma dak li għandek tkun użu kif nimxu isfel, OK. 1006 00:49:53,990 --> 00:49:57,290 1007 00:49:57,290 --> 00:50:01,520 Allura, b hija l-bdil ħaġa unika, id-dritt? 1008 00:50:01,520 --> 00:50:02,910 Mela ejja jimlew kollox. 1009 00:50:02,910 --> 00:50:09,110 1010 00:50:09,110 --> 00:50:11,330 B. X'inhu b se tkun? 1011 00:50:11,330 --> 00:50:13,020 1012 00:50:13,020 --> 00:50:14,140 Li tkun jew ma tkunx. 1013 00:50:14,140 --> 00:50:18,680 1014 00:50:18,680 --> 00:50:20,240 Allura dak li huwa dan isir? 1015 00:50:20,240 --> 00:50:21,605 X'inhu l-istilla pa tagħmel? 1016 00:50:21,605 --> 00:50:23,280 1017 00:50:23,280 --> 00:50:25,350 >> STUDENT: Kodiċi għall-post ta 'pa. 1018 00:50:25,350 --> 00:50:26,390 1019 00:50:26,390 --> 00:50:27,480 >> STUDENT: Le, mhux pjuttost. 1020 00:50:27,480 --> 00:50:29,470 Allura dan huwa referenza d. 1021 00:50:29,470 --> 00:50:31,580 >> STUDENT: Allura b hija valur ekwa ta pa. 1022 00:50:31,580 --> 00:50:37,340 >> PROFESSOR: Yeah, hekk pa huwa l-indirizz ta ', id-dritt? 1023 00:50:37,340 --> 00:50:42,430 Allura huwa qal mur fejn a hija maħżuna u tagħtiha dak il-valur. 1024 00:50:42,430 --> 00:50:43,884 Allura x'inhi b? 1025 00:50:43,884 --> 00:50:44,425 STUDENT: 100. 1026 00:50:44,425 --> 00:50:46,534 PROFESSOR: 100. 1027 00:50:46,534 --> 00:50:47,450 Perfect. 1028 00:50:47,450 --> 00:50:49,879 OK, hekk pc huwa x'hemm tinbidel. 1029 00:50:49,879 --> 00:50:51,170 Kollox jibqa l-istess. 1030 00:50:51,170 --> 00:50:57,160 1031 00:50:57,160 --> 00:50:58,620 X'inhu pc se tkun? 1032 00:50:58,620 --> 00:51:00,770 1033 00:51:00,770 --> 00:51:01,580 Assenjazzjoni sempliċi. 1034 00:51:01,580 --> 00:51:03,520 1035 00:51:03,520 --> 00:51:05,990 Pc hija ugwali għal pa, u dak li huwa pa? 1036 00:51:05,990 --> 00:51:07,049 >> STUDENT: ampersand a. 1037 00:51:07,049 --> 00:51:07,840 PROFESSOR: Perfect. 1038 00:51:07,840 --> 00:51:09,490 1039 00:51:09,490 --> 00:51:10,740 Issa aħna qed jkollna interessanti. 1040 00:51:10,740 --> 00:51:12,310 1041 00:51:12,310 --> 00:51:15,230 OK, ejja break dan wieħed isfel. 1042 00:51:15,230 --> 00:51:21,110 Ewwel, x'hemm darbiet B Ċ, għaliex thats l-parti faċli ta 'dan wieħed, id-dritt? 1043 00:51:21,110 --> 00:51:22,360 Ħinijiet B c is-- 1044 00:51:22,360 --> 00:51:23,320 >> STUDENT: 500. 1045 00:51:23,320 --> 00:51:28,880 >> PROFESSOR: Yeah, hekk dak li huwa dan wieħed tagħmel, 1046 00:51:28,880 --> 00:51:33,705 Jekk huwa star pb, x'hemm qed jinbidlu? 1047 00:51:33,705 --> 00:51:35,320 1048 00:51:35,320 --> 00:51:37,242 >> STUDENT: X'hemm fil the-- 1049 00:51:37,242 --> 00:51:38,200 PROFESSOR: X'hemm fil b? 1050 00:51:38,200 --> 00:51:41,340 STUDENT: X'hemm fl-ispazju li pb hija li tipponta lejn. 1051 00:51:41,340 --> 00:51:43,406 PROFESSOR: u Pb hija li tipponta to-- 1052 00:51:43,406 --> 00:51:43,905 STUDENT: B. 1053 00:51:43,905 --> 00:51:46,740 PROFESSOR: B. Allura l-unika jinbidlu ħaġa hija b, id-dritt. 1054 00:51:46,740 --> 00:51:50,800 Allura b darbiet c, 500. 1055 00:51:50,800 --> 00:51:52,367 Allura dak hu li bidliet issa. 1056 00:51:52,367 --> 00:51:59,091 1057 00:51:59,091 --> 00:51:59,590 Kessaħ. 1058 00:51:59,590 --> 00:52:00,340 1059 00:52:00,340 --> 00:52:00,840 Sabiħ. 1060 00:52:00,840 --> 00:52:01,905 Inti guys qed jagħmlu kbira. 1061 00:52:01,905 --> 00:52:03,650 1062 00:52:03,650 --> 00:52:06,740 Kull dritt, tkissir dan isfel wieħed. 1063 00:52:06,740 --> 00:52:08,050 1064 00:52:08,050 --> 00:52:09,630 C qed tinbidel, id-dritt? 1065 00:52:09,630 --> 00:52:11,530 Allura nistgħu timla kollox. 1066 00:52:11,530 --> 00:52:12,540 1067 00:52:12,540 --> 00:52:13,205 Ejja naraw. 1068 00:52:13,205 --> 00:52:19,125 1069 00:52:19,125 --> 00:52:19,625 OK. 1070 00:52:19,625 --> 00:52:21,420 1071 00:52:21,420 --> 00:52:24,740 Aħna nafu li ċ se tkun l- prodott ta 'żewġ numri, id-dritt? 1072 00:52:24,740 --> 00:52:26,290 1073 00:52:26,290 --> 00:52:27,980 Liema tnejn numri, għalkemm? 1074 00:52:27,980 --> 00:52:28,970 >> STUDENT: A u ċ? 1075 00:52:28,970 --> 00:52:31,930 >> PROFESSOR: Allura huwa dritt għall-ewwel waħda. 1076 00:52:31,930 --> 00:52:34,385 Allura aħna qed D referenzar p ta ', id-dritt? 1077 00:52:34,385 --> 00:52:35,390 1078 00:52:35,390 --> 00:52:42,870 P ta 'punti għal, hekk aħna nafu li dan se jkun 100 darba liema? 1079 00:52:42,870 --> 00:52:46,232 Times What Does punt pc biex? 1080 00:52:46,232 --> 00:52:47,410 1081 00:52:47,410 --> 00:52:48,740 Jindika. 1082 00:52:48,740 --> 00:52:55,038 Allura 100 darba 100 huwa 10,000. 1083 00:52:55,038 --> 00:52:56,170 Does li jagħmel sens? 1084 00:52:56,170 --> 00:52:57,640 1085 00:52:57,640 --> 00:52:58,200 Kessaħ. 1086 00:52:58,200 --> 00:53:00,500 Dar stretch, guys, l-aħħar ringiela. 1087 00:53:00,500 --> 00:53:01,190 OK. 1088 00:53:01,190 --> 00:53:02,160 X'hemm jinbidlu hawn? 1089 00:53:02,160 --> 00:53:05,640 1090 00:53:05,640 --> 00:53:06,935 >> STUDENT: A. 1091 00:53:06,935 --> 00:53:09,435 PROFESSOR: A. Perfect, hekk kollox jistgħu jibqgħu l-istess. 1092 00:53:09,435 --> 00:53:16,210 1093 00:53:16,210 --> 00:53:16,710 OK. 1094 00:53:16,710 --> 00:53:17,970 U dak huwa? 1095 00:53:17,970 --> 00:53:23,610 1096 00:53:23,610 --> 00:53:26,060 Allura huwa drabi liema? 1097 00:53:26,060 --> 00:53:27,120 Dan huwa pb stilla. 1098 00:53:27,120 --> 00:53:29,750 1099 00:53:29,750 --> 00:53:34,490 Allura pb star ifisser hawn pb, punti PB biex b. 1100 00:53:34,490 --> 00:53:35,370 >> STUDENT: 500. 1101 00:53:35,370 --> 00:53:36,230 >> PROFESSOR: 500. 1102 00:53:36,230 --> 00:53:39,236 Allura aħna għandna 500 darba 100. 1103 00:53:39,236 --> 00:53:41,758 C'est 50,000. 1104 00:53:41,758 --> 00:53:43,216 Whew! 1105 00:53:43,216 --> 00:53:45,646 Ħares lejn dak. 1106 00:53:45,646 --> 00:53:47,982 >> STUDENT: Għaliex għandna l-& c għall-last-- 1107 00:53:47,982 --> 00:53:48,690 PROFESSOR: Jiddispjacini. 1108 00:53:48,690 --> 00:53:50,080 STUDENT: Oh, OK. 1109 00:53:50,080 --> 00:53:51,600 PROFESSOR: bad tiegħi. 1110 00:53:51,600 --> 00:53:52,890 Lottijiet ta 'kitba. 1111 00:53:52,890 --> 00:53:53,917 1112 00:53:53,917 --> 00:53:54,500 Kulħadd tajba? 1113 00:53:54,500 --> 00:53:55,630 1114 00:53:55,630 --> 00:53:56,660 Mhux wisq ħażina, right? 1115 00:53:56,660 --> 00:53:58,490 Just tieħu ftit filwaqt li taħdem permezz. 1116 00:53:58,490 --> 00:54:01,080 Jekk inti din tinqasam, jifhmu dak li kull parti 1117 00:54:01,080 --> 00:54:03,197 qed tirreferi to-- bħala ma 'kollox huwa, 1118 00:54:03,197 --> 00:54:05,780 yes-- din tinqasam għall-ftit problemi u mbagħad Begonia, 1119 00:54:05,780 --> 00:54:07,345 u inti tista 'tagħmel xi għalf tal-biża. 1120 00:54:07,345 --> 00:54:08,970 Hemm huma l-tweġibiet, iżda aħna ma li. 1121 00:54:08,970 --> 00:54:10,324 1122 00:54:10,324 --> 00:54:11,115 Aritmetika pointer. 1123 00:54:11,115 --> 00:54:13,961 1124 00:54:13,961 --> 00:54:14,460 Ah. 1125 00:54:14,460 --> 00:54:15,510 Idejn tiegħi huma kollha ġibsi. 1126 00:54:15,510 --> 00:54:17,970 Allura żżid jew tnaqqas int taġġusta l-pointer 1127 00:54:17,970 --> 00:54:21,890 mid-daqs tat-tip ta 'pointer. 1128 00:54:21,890 --> 00:54:22,940 1129 00:54:22,940 --> 00:54:28,390 Ftakar kif kull tip għandu daqs differenti? 1130 00:54:28,390 --> 00:54:34,890 Allura bħal doppja jew twil twil jiġifieri tmienja u int huwa erbgħa iżda char huwa wieħed. 1131 00:54:34,890 --> 00:54:38,360 >> Allura dak li inti trid tagħmel is-- ħaġa waħda li tiftakar 1132 00:54:38,360 --> 00:54:44,080 huwa biss li kemm tiegħek valur pointer attwalment bidliet 1133 00:54:44,080 --> 00:54:46,550 se jiddependi fuq l- tip ta 'pointer huwa. 1134 00:54:46,550 --> 00:54:50,820 1135 00:54:50,820 --> 00:54:51,820 Kulħadd tajba ma dan? 1136 00:54:51,820 --> 00:54:52,760 Nista iħassarha? 1137 00:54:52,760 --> 00:54:53,440 Aħna tajba? 1138 00:54:53,440 --> 00:54:53,940 Biża. 1139 00:54:53,940 --> 00:55:01,020 1140 00:55:01,020 --> 00:55:07,501 >> Hekk jekk ikollna xi pointer that-- dan se be-- jien 1141 00:55:07,501 --> 00:55:08,834 se jagħmilha pointer int. 1142 00:55:08,834 --> 00:55:10,610 1143 00:55:10,610 --> 00:55:12,760 Taħżen dan. 1144 00:55:12,760 --> 00:55:14,210 1145 00:55:14,210 --> 00:55:20,170 Jekk ġejt biex ngħid pointer plus wieħed, dak li għaddej biex tagħmel 1146 00:55:20,170 --> 00:55:23,420 huwa li għaddej biex taġġorna lilha mill-daqs ta 'int 1147 00:55:23,420 --> 00:55:25,950 għaliex dak l- tip ta 'pointer huwa. 1148 00:55:25,950 --> 00:55:28,260 >> Bil C, kollox huwa stretta ħafna u regolat. 1149 00:55:28,260 --> 00:55:29,440 1150 00:55:29,440 --> 00:55:35,260 Il-pointer int se taġġorna minn l-ammont ta 'spazju li int se tieħu. 1151 00:55:35,260 --> 00:55:36,260 An int huwa erba 'bytes. 1152 00:55:36,260 --> 00:55:37,650 1153 00:55:37,650 --> 00:55:39,060 >> Allura dak li dan idur f'korp? 1154 00:55:39,060 --> 00:55:40,876 1155 00:55:40,876 --> 00:55:44,390 Int biss li żżid erba fuq dan. 1156 00:55:44,390 --> 00:55:50,040 Issa pointer tiegħek se be-- OK. 1157 00:55:50,040 --> 00:55:51,820 1158 00:55:51,820 --> 00:55:55,380 >> Mela jekk kien char u għamilna pointer plus wieħed, dak li jkun issa? 1159 00:55:55,380 --> 00:56:00,300 1160 00:56:00,300 --> 00:56:03,330 Jekk started-- feint aħna started-- dritt issa huwa 0x08. 1161 00:56:03,330 --> 00:56:04,850 1162 00:56:04,850 --> 00:56:10,850 Ejja issa ngħid li dan kien char pointer, u aħna miżjud wieħed. 1163 00:56:10,850 --> 00:56:11,850 Liema ser tinbidel għal? 1164 00:56:11,850 --> 00:56:14,989 1165 00:56:14,989 --> 00:56:16,030 Kemm bytes huwa char? 1166 00:56:16,030 --> 00:56:16,680 >> UDJENZA: One. 1167 00:56:16,680 --> 00:56:17,304 >> SPEAKER 1: Wieħed. 1168 00:56:17,304 --> 00:56:18,309 UDJENZA: Allura 0x09. 1169 00:56:18,309 --> 00:56:19,600 SPEAKER 1: Għalhekk ikun disa. 1170 00:56:19,600 --> 00:56:22,571 1171 00:56:22,571 --> 00:56:23,820 Hekk biss xi ħaġa li wieħed jiftakru. 1172 00:56:23,820 --> 00:56:28,340 Just meta inti żid waħda, mhuwiex żżid waħda sakemm huwa char. 1173 00:56:28,340 --> 00:56:34,190 Huwa jżid kemm bytes-tip li huwa, 1174 00:56:34,190 --> 00:56:36,960 huwa għalhekk li għandna din l-ekwazzjoni up here. 1175 00:56:36,960 --> 00:56:40,190 Allura huwa drabi INT-daqs tat-tip ta 'pointer. 1176 00:56:40,190 --> 00:56:42,850 1177 00:56:42,850 --> 00:56:44,730 >> Allura aħna għandna l-eżempju hawn. 1178 00:56:44,730 --> 00:56:47,250 1179 00:56:47,250 --> 00:56:54,430 y ġie assenjat dak il-valur, 0x4, meta għamilna y plus ugwali wieħed. 1180 00:56:54,430 --> 00:56:56,830 X'hemm fiha, x'hemm fil x, ma tinbidilx. 1181 00:56:56,830 --> 00:56:58,610 X'tagħmel il-bidla hija x'hemm y. 1182 00:56:58,610 --> 00:57:04,980 L-indirizz maħżuna fil y aġġornata minn erba ' għaliex hemm erba 'bytes fi int 1183 00:57:04,980 --> 00:57:06,097 u huwa ta 'pointer int. 1184 00:57:06,097 --> 00:57:07,290 1185 00:57:07,290 --> 00:57:07,790 >> Kull dritt. 1186 00:57:07,790 --> 00:57:09,123 Allura issa għandna ieħor eżerċizzju. 1187 00:57:09,123 --> 00:57:11,140 1188 00:57:11,140 --> 00:57:13,500 Għalhekk il-kwistjoni huwa dak li se print. 1189 00:57:13,500 --> 00:57:36,710 1190 00:57:36,710 --> 00:57:37,650 Xi ideat? 1191 00:57:37,650 --> 00:57:41,690 1192 00:57:41,690 --> 00:57:43,699 >> UDJENZA: In-numru ta ' karattri fit qattus kuntenti? 1193 00:57:43,699 --> 00:57:44,490 SPEAKER 1: Eżattament. 1194 00:57:44,490 --> 00:57:45,531 Allura simili ma string tiegħek. 1195 00:57:45,531 --> 00:57:47,302 1196 00:57:47,302 --> 00:57:48,260 Does kulħadd nikseb dan? 1197 00:57:48,260 --> 00:57:49,509 Do irridu li jimxu permezz ta 'dan? 1198 00:57:49,509 --> 00:57:50,300 1199 00:57:50,300 --> 00:57:52,010 >> Iva, OK. 1200 00:57:52,010 --> 00:57:57,385 Allura dak li għandna here-- I bħal dan hekk ħafna aktar. 1201 00:57:57,385 --> 00:57:59,340 I ma jkollhom [Inaudible] ridiculously. 1202 00:57:59,340 --> 00:58:01,690 >> Allura aħna għandna string tagħna hawn, qattus kuntenti. 1203 00:58:01,690 --> 00:58:02,950 Sabiħ. 1204 00:58:02,950 --> 00:58:05,080 Għandna xi kontro li aħna qed iżżomm rekord ta '. 1205 00:58:05,080 --> 00:58:11,430 Allura aħna għandna xi char * pointer li ftit huwa stabbilit ugwali għal str. 1206 00:58:11,430 --> 00:58:14,320 X'inhu dan qed tagħmel huwa huwa tassenja xi pointer 1207 00:58:14,320 --> 00:58:16,380 għall-bidu ta 'spag tiegħek. 1208 00:58:16,380 --> 00:58:19,840 Għaliex jien ċert, kif kien imsemmi fil lecture, 1209 00:58:19,840 --> 00:58:22,290 konna tak guys dan tip ta 'data msejħa string. 1210 00:58:22,290 --> 00:58:29,070 >> Imma verament kordi huma biss firxa of-- bħal char *. 1211 00:58:29,070 --> 00:58:32,330 Huwa pointer għal mazz ta 'karattri li huma kontigwi fil-memorja. 1212 00:58:32,330 --> 00:58:33,680 1213 00:58:33,680 --> 00:58:36,280 Allura dan biss jistabbilixxi dan ugwali għal kwalunkwe string hija 1214 00:58:36,280 --> 00:58:38,980 identifikati minn fejn ewwel karattru tagħha huwa. 1215 00:58:38,980 --> 00:58:42,710 Allura dan huwa biss iffissar f'xi punt ugwali għall-bidu tas-sekwenza. 1216 00:58:42,710 --> 00:58:44,130 Kulħadd tajba hemmhekk? 1217 00:58:44,130 --> 00:58:44,960 Kessaħ. 1218 00:58:44,960 --> 00:58:49,840 >> Allura dan huwa dereferencing pointer tagħna. 1219 00:58:49,840 --> 00:58:53,760 Allura huwa attwalment għaddejjin biex tagħtina xi valur fil hawn, 1220 00:58:53,760 --> 00:58:55,610 fil string tagħna li aħna qed jitkellem dwar. 1221 00:58:55,610 --> 00:58:58,342 U aħna qed tgħid sakemm mhuwiex terminatur null. 1222 00:58:58,342 --> 00:59:00,550 Allura iżommu għaddejjin sakemm ikollok sa l-aħħar tas-sekwenza. 1223 00:59:00,550 --> 00:59:02,180 1224 00:59:02,180 --> 00:59:04,190 Taġġorna pointer tiegħek minn waħda. 1225 00:59:04,190 --> 00:59:09,250 Allura r, huwa fil-fatt se taġġorna minn wieħed kull darba minħabba li din hija char, 1226 00:59:09,250 --> 00:59:09,820 l char *. 1227 00:59:09,820 --> 00:59:10,930 1228 00:59:10,930 --> 00:59:12,340 >> Allura li għaddej biex jgħaddu. 1229 00:59:12,340 --> 00:59:13,290 Li għaddej biex taġġorna. 1230 00:59:13,290 --> 00:59:16,705 Allura l-ewwel darba din runs, li għaddej biex jkun hawn fil h. 1231 00:59:16,705 --> 00:59:17,590 Li għaddej biex taġġorna. 1232 00:59:17,590 --> 00:59:18,185 >> Hija ser tkun a. 1233 00:59:18,185 --> 00:59:21,310 Hija ser tkun p, y, u hekk u ibqa 'sejjer hekk. 1234 00:59:21,310 --> 00:59:22,300 Aħna ser taġġorna counter. 1235 00:59:22,300 --> 00:59:26,160 Meta jilħaq il-għan, huwa biss prints kemm huwa gotten. 1236 00:59:26,160 --> 00:59:27,550 1237 00:59:27,550 --> 00:59:28,050 Iva. 1238 00:59:28,050 --> 00:59:31,475 >> UDJENZA: Allura Huwa jgħodd l-ispazju bħala waħda, id-dritt? 1239 00:59:31,475 --> 00:59:31,974 OK. 1240 00:59:31,974 --> 00:59:34,294 1241 00:59:34,294 --> 00:59:35,222 >> SPEAKER 1: Aħseb hekk. 1242 00:59:35,222 --> 00:59:36,830 Huwa li question-- 1243 00:59:36,830 --> 00:59:37,746 >> UDJENZA: [inaudible]. 1244 00:59:37,746 --> 00:59:37,968 1245 00:59:37,968 --> 00:59:38,884 >> SPEAKER 1: Nru inkwiet. 1246 00:59:38,884 --> 00:59:39,720 1247 00:59:39,720 --> 00:59:42,736 Dan I tagħmel dan. 1248 00:59:42,736 --> 00:59:47,710 Kull dritt, hekk ħaġa waħda I jifhem li ma 'firxa, 1249 00:59:47,710 --> 00:59:51,736 inti tista 'wkoll titratta dan bħala pointer minħabba arrays huma biss 1250 00:59:51,736 --> 00:59:52,860 spots kontinwu ta 'memorja. 1251 00:59:52,860 --> 00:59:53,970 1252 00:59:53,970 --> 00:59:56,380 >> Allura inti tista 'titratta dan l-istess mod. 1253 00:59:56,380 --> 00:59:59,000 Inti tista 'timmanipola lilhom ma pointers, wisq. 1254 00:59:59,000 --> 01:00:04,770 Allura minflok tagħmel, f'dan il- każ, il-ħaġa analoga 1255 01:00:04,770 --> 01:00:07,490 Ikun firxa 0 ugwali 1. 1256 01:00:07,490 --> 01:00:08,760 1257 01:00:08,760 --> 01:00:15,210 >> Iżda fl-istess mod li string huwa determinat 1258 01:00:15,210 --> 01:00:18,740 mill-bidu ta 'fejn ewwel karattru tagħha hija, 1259 01:00:18,740 --> 01:00:22,270 firxa huwa determinat mill fejn l-ewwel element tagħha huwa. 1260 01:00:22,270 --> 01:00:25,120 Għaliex nafu, aħna qed garantit, li dawn 1261 01:00:25,120 --> 01:00:27,985 ser ikunu kontinwa blokki ta 'memorja. 1262 01:00:27,985 --> 01:00:29,360 Dak hu li jippermetti li jagħmlu dan. 1263 01:00:29,360 --> 01:00:31,193 Nafu li qed kontinwa blokki ta 'memorja. 1264 01:00:31,193 --> 01:00:32,230 1265 01:00:32,230 --> 01:00:36,500 >> Allura f'dan il-każ, billi dereferencing biss firxa, li tgħidilna, 1266 01:00:36,500 --> 01:00:40,800 OK, mur l-bidu ta ' array tiegħek, li huwa hawnhekk. 1267 01:00:40,800 --> 01:00:42,640 Allura inti tista 'tistabbilixxi lilha ugwali għal wieħed. 1268 01:00:42,640 --> 01:00:48,610 U f'dan il-każ, ikun x'ikun firxa tiegħek tip huwa, meta inti jaġġornah minn wieħed, 1269 01:00:48,610 --> 01:00:50,830 li jinsab biss bħall-aġġornament lill-indiċi li jmiss. 1270 01:00:50,830 --> 01:00:52,760 1271 01:00:52,760 --> 01:00:56,360 Tista 'tagħmel dan għaliex inti jafu x'hemm fil-firxa tiegħek. 1272 01:00:56,360 --> 01:00:59,770 Għalhekk jaf kemm biex taġġorna pointer tiegħek billi, 1273 01:00:59,770 --> 01:01:02,925 dak l-indirizz li jaġġornah biex hekk li int fil-slot li jmiss. 1274 01:01:02,925 --> 01:01:04,740 1275 01:01:04,740 --> 01:01:09,400 >> Allura dan huwa biss mod differenti tal-kitba firxa 0 ugwali 1, 1276 01:01:09,400 --> 01:01:15,114 array 1 huwa ugwali għal 2, array bracket 2 ugwali 3. 1277 01:01:15,114 --> 01:01:16,780 Huwa biss mod ieħor biex jaħsbu dwar dan. 1278 01:01:16,780 --> 01:01:19,600 Minħabba li huma kontinwi blokki fil-memorja, 1279 01:01:19,600 --> 01:01:21,830 inti tista 'tirreferi għalihom jew mill-firxa notation-- 1280 01:01:21,830 --> 01:01:24,390 li jien personalment isibu easier-- imma forsi 1281 01:01:24,390 --> 01:01:27,347 għandek bżonn biex jimmanipulaw b'mod strett mill-indirizzi memorja. 1282 01:01:27,347 --> 01:01:28,930 U dan huwa l-mod inti tagħmel dan. 1283 01:01:28,930 --> 01:01:30,630 1284 01:01:30,630 --> 01:01:32,630 Tip ta 'aktar simili ta' jibred ħaġa inti tista 'tagħmel 1285 01:01:32,630 --> 01:01:35,213 versus forsi mhux xi ħaġa int attwalment għaddejjin biex jimplimentaw. 1286 01:01:35,213 --> 01:01:36,960 1287 01:01:36,960 --> 01:01:38,630 >> I użu fil 61. 1288 01:01:38,630 --> 01:01:41,710 Inti guys probabbilment ma bżonn għalfejn tinkwieta dwar dan wisq. 1289 01:01:41,710 --> 01:01:43,693 Imma jekk int interessat, jieħu 61 sena d-dieħla. 1290 01:01:43,693 --> 01:01:45,269 1291 01:01:45,269 --> 01:01:46,560 Aħna fil-guys stretch dar. 1292 01:01:46,560 --> 01:01:47,510 Naf, huwa twil. 1293 01:01:47,510 --> 01:01:50,570 1294 01:01:50,570 --> 01:01:58,880 Dynamic Memorja Allocation-- hekk aħna nafu li wieħed 1295 01:01:58,880 --> 01:02:01,790 ta 'affarijiet meta tkellimna matul ewwel taqsima tagħna flimkien, 1296 01:02:01,790 --> 01:02:04,560 ħarisna lejn swap funzjoni fejn kien 1297 01:02:04,560 --> 01:02:08,010 barra mill-ambitu tal-funzjoni prinċipali tagħna. 1298 01:02:08,010 --> 01:02:14,370 U konna tgħaddi dawn il-valuri li kienu effettivament kopji. 1299 01:02:14,370 --> 01:02:20,570 >> U ladarba swap lest eżekuzzjoni, hija biss ħalla munzell. 1300 01:02:20,570 --> 01:02:22,830 Ftakar, aħna għandna munzell qafas għall swap. 1301 01:02:22,830 --> 01:02:26,070 Tħalli u dawk Valuri jitilqu miegħu. 1302 01:02:26,070 --> 01:02:27,050 U kienu marru. 1303 01:02:27,050 --> 01:02:28,615 Aħna ma setgħux jagħmlu xejn magħhom u konna imdejjaq 1304 01:02:28,615 --> 01:02:29,989 għaliex aħna ma tistax tpartit valuri tagħna. 1305 01:02:29,989 --> 01:02:31,070 1306 01:02:31,070 --> 01:02:36,560 >> Iżda ma Ċ, kif semmejt, inti għandhom ħafna ta 'setgħa fuq memorja. 1307 01:02:36,560 --> 01:02:43,310 Allura dak li inti tista 'tagħmel huwa inti tista' talloka l-affarijiet fuq il-borġ hawn 1308 01:02:43,310 --> 01:02:46,830 li se jibqgħu hemm sakemm inti jgħidulhom mod ieħor. 1309 01:02:46,830 --> 01:02:48,280 >> Huma qed simili tfal tajba. 1310 01:02:48,280 --> 01:02:49,150 Huma jibqgħu hemm. 1311 01:02:49,150 --> 01:02:50,270 Huma ma jħallu. 1312 01:02:50,270 --> 01:02:52,750 Dawn ser jibqgħu hemm sakemm int simili, OK, inti tista 'tmur bogħod. 1313 01:02:52,750 --> 01:02:55,920 >> Billi affarijiet fuq il-munzell, who-- dawn qed bħat-tfal imqareb. 1314 01:02:55,920 --> 01:02:59,160 Huma ser biss run bogħod meta inti tixtieq li jkun hemm u allura dawn qed marret. 1315 01:02:59,160 --> 01:03:00,160 Inti ma tistax tikseb minnhom lura. 1316 01:03:00,160 --> 01:03:01,350 1317 01:03:01,350 --> 01:03:07,187 >> Allura l-borġ is-- aħna qed tmur biex jitkellmu dwar malloc u ħielsa, li 1318 01:03:07,187 --> 01:03:08,895 Jien ċert li inti guys jinstemgħu dwar fil lecture. 1319 01:03:08,895 --> 01:03:10,270 1320 01:03:10,270 --> 01:03:14,210 U li bażikament mezz li jkollhom data persistenti ħafna. 1321 01:03:14,210 --> 01:03:18,920 Sabiex inti tista 'żżomm l-informazzjoni madwar sakemm inti tixtieq. 1322 01:03:18,920 --> 01:03:19,546 MHM. 1323 01:03:19,546 --> 01:03:21,475 >> UDJENZA: Inti tista 'tiddefinixxi borġ u munzell? 1324 01:03:21,475 --> 01:03:24,030 Dawn huma simili postijiet biex l-affarijiet? 1325 01:03:24,030 --> 01:03:26,630 >> SPEAKER 1: Allura dawn qed bażikament just-- dawn qed 1326 01:03:26,630 --> 01:03:29,530 il-mod aħna jirreferu biss għall-memorja. 1327 01:03:29,530 --> 01:03:37,300 Allura borġ huwa biss postijiet fejn memorja hija allokata dinamikament, 1328 01:03:37,300 --> 01:03:40,960 billi munzell jirreferi aktar biex jistivaw frames 1329 01:03:40,960 --> 01:03:45,950 li huma aktar ċentrali għall- funzjonijiet li huma attwalment running. 1330 01:03:45,950 --> 01:03:47,200 Inti ma verament ikollhom kontroll. 1331 01:03:47,200 --> 01:03:50,690 >> Id-differenza kbira, inti għandek kontroll fuq il-borġ jekk inti tixtieq li. 1332 01:03:50,690 --> 01:03:52,710 Għandek inqas kontroll fuq il-munzell. 1333 01:03:52,710 --> 01:03:55,030 Il-munzell tiddependi fuq il- funzjonijiet li huma running, 1334 01:03:55,030 --> 01:03:58,320 u l-ordni li fiha huma run, u kif l-affarijiet huma ritornati. 1335 01:03:58,320 --> 01:04:01,290 Billi bil-borġ, kif Ser naraw, inti tista 'tgħid, 1336 01:04:01,290 --> 01:04:06,639 OK, Irrid dan il-valur li jkun madwar sakemm I jgħidlek mod ieħor. 1337 01:04:06,639 --> 01:04:08,180 M'intix permess biex jeħles minnu. 1338 01:04:08,180 --> 01:04:09,300 Int mhux permess li jiskarta dan. 1339 01:04:09,300 --> 01:04:11,675 Inti qed tmur biex jżommha madwar sakemm I jgħidlek. 1340 01:04:11,675 --> 01:04:15,780 Ikollok biex tkun il-boxxla fil-borġ, billi l-stack-- forsi jekk inti 1341 01:04:15,780 --> 01:04:18,080 bħall finagle tiegħek mod inti tista 'tkun il-boxxla. 1342 01:04:18,080 --> 01:04:19,340 Iżda pjuttost mhux. 1343 01:04:19,340 --> 01:04:20,480 1344 01:04:20,480 --> 01:04:22,070 U huwa verament ftit memorja. 1345 01:04:22,070 --> 01:04:24,260 Huwa modi biss differenti tirreferi għall-memorja. 1346 01:04:24,260 --> 01:04:25,800 1347 01:04:25,800 --> 01:04:26,400 >> Kessaħ. 1348 01:04:26,400 --> 01:04:28,630 Allura ma 'dan, kif kontroll memorja tiegħek. 1349 01:04:28,630 --> 01:04:32,070 Huwa ma malloc, li int ser jiksbu l-użu. 1350 01:04:32,070 --> 01:04:37,100 Allura huwa biss qasir għall-allokazzjoni memorja. 1351 01:04:37,100 --> 01:04:38,459 Li kollox huwa. 1352 01:04:38,459 --> 01:04:41,250 Hemm mazz ta 'jibred oħra funzjonijiet li jkollhom ALLOC fl-aħħar, 1353 01:04:41,250 --> 01:04:42,750 u inhuma għall-affarijiet differenti. 1354 01:04:42,750 --> 01:04:43,550 1355 01:04:43,550 --> 01:04:49,050 >> Allura meta għandek bżonn ħażna li teħtieġ outlast funzjoni attwali tiegħek sabiex 1356 01:04:49,050 --> 01:04:51,010 li meta attwali tiegħek funzjoni runs bogħod, 1357 01:04:51,010 --> 01:04:55,774 inti għad għandek l-informazzjoni li inti ltqajna minnha, inti tixtieq li tuża malloc. 1358 01:04:55,774 --> 01:04:57,190 Li ser initialize fuq il-borġ. 1359 01:04:57,190 --> 01:05:00,140 U bħal I said u jżomm qal, inti ser żommu hemm 1360 01:05:00,140 --> 01:05:03,050 sakemm inti għid mod ieħor, li huwa l-ħaġa importanti hawnhekk. 1361 01:05:03,050 --> 01:05:08,450 >> Allura ħaġa waħda li l-avviż, u li tipikament verament importanti, 1362 01:05:08,450 --> 01:05:13,620 hija li dan sizeof huwa super utli li tintuża 1363 01:05:13,620 --> 01:05:16,440 għaliex skond it-tip ta 'magna int taħdem, 1364 01:05:16,440 --> 01:05:22,470 jista 'jkollhom ammonti varjabbli ta 'memorja li jieħu. 1365 01:05:22,470 --> 01:05:26,870 Allura inti dejjem tixtieq li tuża daqs ta 'hekk li int mhux magna dipendenti, 1366 01:05:26,870 --> 01:05:30,300 hekk li kodiċi tiegħek se jimxu fuq kull magna. 1367 01:05:30,300 --> 01:05:32,360 >> U dan huwa biss parti tal-kitba kodiċi tajba. 1368 01:05:32,360 --> 01:05:34,610 Jekk din taħdem fuq magna waħda, iżda mhux kwalunkwe mill-oħrajn, 1369 01:05:34,610 --> 01:05:36,440 kif utli kien program tiegħek? 1370 01:05:36,440 --> 01:05:38,420 Allura inti dejjem tixtieq li kun żgur u l-użu sizeof. 1371 01:05:38,420 --> 01:05:41,306 >> UDJENZA: Allura huwa li bħall- daqs ta '10 pulzier [inaudible]? 1372 01:05:41,306 --> 01:05:43,698 >> SPEAKER 1: Dan huwa d-daqs ta '10 ints. 1373 01:05:43,698 --> 01:05:44,197 yeah. 1374 01:05:44,197 --> 01:05:45,360 1375 01:05:45,360 --> 01:05:48,830 Allura daqs tal ints se terġa 'lura kemm ma int wieħed jieħu. 1376 01:05:48,830 --> 01:05:51,530 Jew id-daqs ta 'char, kif Ħafna Does wieħed char jieħdu. 1377 01:05:51,530 --> 01:05:54,150 U allura kif ħafna blokki ta 'dak tridu? 1378 01:05:54,150 --> 01:05:57,590 >> Allura f'dan il-każ, irridu xi ħaġa li nistgħu jaħżen 10 ints sa. 1379 01:05:57,590 --> 01:06:00,240 U se taħdem indipendentement ta 'magna, li huwa jibred. 1380 01:06:00,240 --> 01:06:01,720 1381 01:06:01,720 --> 01:06:04,846 Allura kif ħafna bytes se li attwalment jagħtuk? 1382 01:06:04,846 --> 01:06:06,190 Quick matematika. 1383 01:06:06,190 --> 01:06:06,787 >> UDJENZA: 40. 1384 01:06:06,787 --> 01:06:07,370 SPEAKER 1: 40. 1385 01:06:07,370 --> 01:06:07,869 Eżattament. 1386 01:06:07,869 --> 01:06:09,520 1387 01:06:09,520 --> 01:06:12,030 Allura ieħor ħaġa kbira. 1388 01:06:12,030 --> 01:06:14,840 Pointer jew malloc jistgħu jirritornaw null. 1389 01:06:14,840 --> 01:06:17,910 >> Għalhekk għal darb'oħra, dejjem tikkontrolla biex ara jekk ritornat null 1390 01:06:17,910 --> 01:06:19,620 qabel ma inti tipprova tagħmel xejn magħha. 1391 01:06:19,620 --> 01:06:23,430 1392 01:06:23,430 --> 01:06:27,350 Jekk inti tipprova u dereference dan il-werrej issa, 1393 01:06:27,350 --> 01:06:29,720 huwa biss se segfault għaliex inti marru u ppruvaw 1394 01:06:29,720 --> 01:06:31,730 tmissx null meta m'għandekx ikollok. 1395 01:06:31,730 --> 01:06:34,000 Allura dejjem jiċċekkja għal null. 1396 01:06:34,000 --> 01:06:36,075 Għal darb'oħra, inti kollha tista 'tagħmel. 1397 01:06:36,075 --> 01:06:38,300 1398 01:06:38,300 --> 01:06:39,720 >> Jista ritorn null. 1399 01:06:39,720 --> 01:06:42,740 Hija ser jirritorna null jekk int jew ta 'spazju, jew għal kwalunkwe raġuni 1400 01:06:42,740 --> 01:06:44,350 dan dam fis xi bug memorja. 1401 01:06:44,350 --> 01:06:45,890 1402 01:06:45,890 --> 01:06:47,510 Hija xi kultant jirritorna null. 1403 01:06:47,510 --> 01:06:48,990 Allura inti biss għandek biex jiċċekkjaw għaliha. 1404 01:06:48,990 --> 01:06:51,050 C'est dan kollu slide huwa qal. 1405 01:06:51,050 --> 01:06:53,366 1406 01:06:53,366 --> 01:06:55,240 U allura dak li għandna hawnhekk huwa sejħa għal free. 1407 01:06:55,240 --> 01:07:00,550 Allura bl-istess mod li jekk inti jiftaħ fajl inti trid tagħlaq fajl, 1408 01:07:00,550 --> 01:07:04,340 jekk inti memorja malloc, inti għandu inti liberu li l-memorja. 1409 01:07:04,340 --> 01:07:06,530 U inti guys se tikseb tagħmel Jittieħed verament jibred. 1410 01:07:06,530 --> 01:07:09,624 >> U hemm program inti tista 'taħdem biex ara jekk int qatt jnixxu memorja. 1411 01:07:09,624 --> 01:07:11,040 Imma inti ma tridx li jnixxi memorja. 1412 01:07:11,040 --> 01:07:11,820 Huwa tassew ħżiena. 1413 01:07:11,820 --> 01:07:13,191 1414 01:07:13,191 --> 01:07:15,020 Mess up biss affarijiet. 1415 01:07:15,020 --> 01:07:20,939 >> Huwa ħażin li tagħmel bħad-ipprogrammar għaqli għall-effiċjenza tad-disinn. 1416 01:07:20,939 --> 01:07:22,980 Imma hija wkoll biss tip ta ħażin għall-kompjuter tiegħek. 1417 01:07:22,980 --> 01:07:26,780 Affarijiet hekk biss ħielsa meta inti malloc lilhom. 1418 01:07:26,780 --> 01:07:28,190 1419 01:07:28,190 --> 01:07:30,210 >> You guys tara l-symmetries hawn. 1420 01:07:30,210 --> 01:07:31,180 Super sempliċi. 1421 01:07:31,180 --> 01:07:33,010 Just libera u imbagħad ikun x'ikun pointer tiegħek, 1422 01:07:33,010 --> 01:07:34,843 ikun x'ikun l-isem ta ' pointer tiegħek huwa, u 1423 01:07:34,843 --> 01:07:36,710 se jieħdu ħsieb ta jinħeles dan għalik. 1424 01:07:36,710 --> 01:07:38,200 1425 01:07:38,200 --> 01:07:38,700 Kessaħ. 1426 01:07:38,700 --> 01:07:40,410 1427 01:07:40,410 --> 01:07:42,530 >> Allura għandna dan. 1428 01:07:42,530 --> 01:07:44,770 Allura aħna qed biss jmorru jimxu permezz ta 'dan il-programm. 1429 01:07:44,770 --> 01:07:46,560 U allura inti guys qed isir. 1430 01:07:46,560 --> 01:07:50,240 >> Allura [inaudible] biss prinċipali. 1431 01:07:50,240 --> 01:07:51,690 Allura aħna għandna xi int * pointer. 1432 01:07:51,690 --> 01:07:53,648 Allura aħna għandna pointer li għaddej biex iżommu ints. 1433 01:07:53,648 --> 01:07:54,500 1434 01:07:54,500 --> 01:07:56,170 U kemm ints huwa se żżomm? 1435 01:07:56,170 --> 01:07:57,400 1436 01:07:57,400 --> 01:07:58,170 Just wieħed. 1437 01:07:58,170 --> 01:07:59,400 1438 01:07:59,400 --> 01:08:01,100 Daqs ta 'int. 1439 01:08:01,100 --> 01:08:03,900 >> Aħna tikkontrolla biex tara jekk pointer huwa null għaliex 1440 01:08:03,900 --> 01:08:06,130 huwa, irridu ngħidu ma tagħmel xejn. 1441 01:08:06,130 --> 01:08:07,065 Huwa ħażin. 1442 01:08:07,065 --> 01:08:08,130 1443 01:08:08,130 --> 01:08:12,130 Allura aħna jistampaw xi żball barra mill memorja, ħafna drabi ritorn 1, 1444 01:08:12,130 --> 01:08:14,260 Kif inti guys huma użati biex. 1445 01:08:14,260 --> 01:08:17,390 >> U allura għandna hawnhekk, aħna dereference pointer tagħna. 1446 01:08:17,390 --> 01:08:22,840 Allura dan ifisser li aħna qed tmur biex jaħżnu xi ħaġa fil-post mogħti lilna. 1447 01:08:22,840 --> 01:08:24,350 1448 01:08:24,350 --> 01:08:30,830 Int * pointer, jew malloc, jirritorna l- indirizz ta 'fejn titwarrab din 1449 01:08:30,830 --> 01:08:31,750 memorja għalik. 1450 01:08:31,750 --> 01:08:32,830 1451 01:08:32,830 --> 01:08:34,800 Allura huwa bażikament giving you like-- jekk inti 1452 01:08:34,800 --> 01:08:38,149 jaħsbu dwar mazz ta ' djar fil-lokal 1453 01:08:38,149 --> 01:08:40,640 li inti tixtieq li tqiegħed tiegħek fl-għamara, malloc 1454 01:08:40,640 --> 01:08:43,850 huwa simili OK, ikollok biex tmur għall-dar tlieta. 1455 01:08:43,850 --> 01:08:45,800 U jagħtik l- indirizz tad-dar tlieta. 1456 01:08:45,800 --> 01:08:48,775 >> Allura dan id-dritt issa, dan ħwienet pointer indirizz, 1457 01:08:48,775 --> 01:08:50,149 Taħżen-indirizz tad-dar tiegħek. 1458 01:08:50,149 --> 01:08:51,470 1459 01:08:51,470 --> 01:08:54,640 * mezzi PTR, OK, jien fil-dar tiegħi. 1460 01:08:54,640 --> 01:08:55,326 Kessaħ. 1461 01:08:55,326 --> 01:08:56,580 Għandi bżonn nikseb xi numru sħiħ. 1462 01:08:56,580 --> 01:08:59,229 >> Allura inti qed tistaqsi għal xi ħadd li jtik l-għamara issa. 1463 01:08:59,229 --> 01:09:00,430 Allura ikollok xi int. 1464 01:09:00,430 --> 01:09:05,100 U tpoġġiha hija fil pointer tiegħek fejn huwa tipponta lejn. 1465 01:09:05,100 --> 01:09:08,670 >> U allura biss prints out, inti daħal kulfejn. 1466 01:09:08,670 --> 01:09:11,060 U għal darb'oħra, ir-referenza. 1467 01:09:11,060 --> 01:09:15,649 Allura dan huwa simili inti marru għal dan jindirizzaw u inti raw dak li kien hemm. 1468 01:09:15,649 --> 01:09:17,120 1469 01:09:17,120 --> 01:09:17,630 Kessaħ? 1470 01:09:17,630 --> 01:09:20,174 >> U allura naturalment aħna ħielsa pointer tagħna. 1471 01:09:20,174 --> 01:09:21,590 Tinsiex biex ħielsa pointer tiegħek. 1472 01:09:21,590 --> 01:09:22,933 Tinsiex sabiex jikkontrolla għal null. 1473 01:09:22,933 --> 01:09:24,349 Tinsiex biex ħielsa pointer tiegħek. 1474 01:09:24,349 --> 01:09:27,270 Għandek żewġ affarijiet li għandek tiftakar minn dan, jew li għandek tiftakar. 1475 01:09:27,270 --> 01:09:27,770 Iva. 1476 01:09:27,770 --> 01:09:31,590 UDJENZA: Jittieħed [inaudible] bħal dik, l-char * i. 1477 01:09:31,590 --> 01:09:33,760 Kif come aħna qatt ħielsa dawk? 1478 01:09:33,760 --> 01:09:34,529 >> SPEAKER 1: Hm? 1479 01:09:34,529 --> 01:09:36,450 >> UDJENZA: Huma dawk bħal kordi? 1480 01:09:36,450 --> 01:09:39,160 You qal kordi huma bħad char * i, id-dritt? 1481 01:09:39,160 --> 01:09:41,200 Allura għaliex ma we ħielsa kordi? 1482 01:09:41,200 --> 01:09:43,204 >> SPEAKER 1: Inti biss biex ħielsa jekk int mallocing. 1483 01:09:43,204 --> 01:09:44,620 UDJENZA: Oh, jekk int mallocing. 1484 01:09:44,620 --> 01:09:47,399 SPEAKER 1: Allura malloc u ħielsa huma żewġ affarijiet 1485 01:09:47,399 --> 01:09:49,000 li għandek dejjem ikollhom flimkien. 1486 01:09:49,000 --> 01:09:51,630 f miftuħa, qrib f, żewġ affarijiet għandu jkollok flimkien. 1487 01:09:51,630 --> 01:09:54,471 F'dawk il-każijiet iż-żewġ, iċċekkja għall null. 1488 01:09:54,471 --> 01:09:54,971 Iva. 1489 01:09:54,971 --> 01:09:57,130 >> UDJENZA: Allura ħielsa hija biss tippermetti xi ħaġa oħra 1490 01:09:57,130 --> 01:09:59,690 li jiġu maħżuna hemmhekk wara dan il-programm ikun uża dan? 1491 01:09:59,690 --> 01:10:01,946 >> SPEAKER 1: Huwa biss qal, OK, jien jsir ma 'dan. 1492 01:10:01,946 --> 01:10:03,320 Inti ma għandekx bżonn li jżommha madwar. 1493 01:10:03,320 --> 01:10:05,340 1494 01:10:05,340 --> 01:10:08,190 Inkella kompjuter tiegħek se Eżatt bħal jippruvaw u żommu hemmhekk. 1495 01:10:08,190 --> 01:10:10,910 U allura inti can't-- din tmur dwar kwistjonijiet memorja aktar tard. 1496 01:10:10,910 --> 01:10:13,660 Int dejjem tixtieq li ħielsa għaliex jgħidlek kompjuter tiegħek, OK, jien 1497 01:10:13,660 --> 01:10:15,190 isir ma 'dan il-post ta' memorja. 1498 01:10:15,190 --> 01:10:17,190 Inti jista 'jkollhom lura biex nagħmel użu aktar tard. 1499 01:10:17,190 --> 01:10:19,250 1500 01:10:19,250 --> 01:10:20,500 Kessaħ? 1501 01:10:20,500 --> 01:10:21,320 Iva. 1502 01:10:21,320 --> 01:10:26,950 >> UDJENZA: Allura aħna użati l-% d eżatt minħabba doppja thats ġejjin lura, 1503 01:10:26,950 --> 01:10:28,330 jew għaliex is-- [inaudible]. 1504 01:10:28,330 --> 01:10:30,170 1505 01:10:30,170 --> 01:10:31,620 >> UDJENZA: Tista 'tuża i%? 1506 01:10:31,620 --> 01:10:32,760 >> SPEAKER 1: Tista 'tuża% i. 1507 01:10:32,760 --> 01:10:35,052 1508 01:10:35,052 --> 01:10:36,135 Kwalunkwe mistoqsijiet aħħar minuta? 1509 01:10:36,135 --> 01:10:38,310 1510 01:10:38,310 --> 01:10:38,985 Jimxi 'l quddiem. 1511 01:10:38,985 --> 01:10:40,610 UDJENZA: I biss mistoqsija ta 'malajr. 1512 01:10:40,610 --> 01:10:50,200 Allura l-varjabbli PTR, that's-- simili, bl-PTR int * = malloc, 1513 01:10:50,200 --> 01:10:54,142 thats biss qal huwa tipponta lejn post fil memory-- 1514 01:10:54,142 --> 01:10:55,600 SPEAKER 1: Tixtieq [inaudible]? 1515 01:10:55,600 --> 01:10:58,050 UDJENZA: --that hija l- daqs of-- ebda, huwa OK. 1516 01:10:58,050 --> 01:11:01,292 Iżda huwa biss li tipponta lejn post fl memorja li jinsab biss bħall-erba 'bytes. 1517 01:11:01,292 --> 01:11:02,000 SPEAKER 1: Dritt. 1518 01:11:02,000 --> 01:11:03,030 1519 01:11:03,030 --> 01:11:07,070 Allura malloc-daqs ta 'int jgħid, OK, jien ser jmorru run off, 1520 01:11:07,070 --> 01:11:08,780 isibu erba bytes ta 'memorja għalik. 1521 01:11:08,780 --> 01:11:10,700 Meta ssib li erbgħa bytes ta 'memorja, dan 1522 01:11:10,700 --> 01:11:14,030 jagħtik lura l-indirizz ta 'fejn tibda, 1523 01:11:14,030 --> 01:11:16,160 u dan huwa dak maħżuna fil pointer, jew PTR. 1524 01:11:16,160 --> 01:11:17,510 1525 01:11:17,510 --> 01:11:18,010 Tajba. 1526 01:11:18,010 --> 01:11:18,742 1527 01:11:18,742 --> 01:11:21,700 Inti guys tfittex inqas konfuż minn ħafna nies meta I jitkellmu dwar pointer, 1528 01:11:21,700 --> 01:11:23,670 hekk jien tħossok pjuttost tajba dritt issa. 1529 01:11:23,670 --> 01:11:24,520 >> Kull dritt. 1530 01:11:24,520 --> 01:11:27,960 Bħal dejjem, inti guys għandek kollha gotten gradi pset2 tiegħek minn issa. 1531 01:11:27,960 --> 01:11:32,769 Naf kien hemm xi wonky affarijiet fejn jgħid, formula mhix valida 1532 01:11:32,769 --> 01:11:33,310 jew xi ħaġa. 1533 01:11:33,310 --> 01:11:36,166 Jekk int jkollna dak, kollha ta ' gradi tiegħek huma validi fuq in-naħa tiegħi. 1534 01:11:36,166 --> 01:11:38,040 So I tista 'tibgħat inti screenshots ta 'gradi tiegħek. 1535 01:11:38,040 --> 01:11:39,011 1536 01:11:39,011 --> 01:11:41,760 Just let me know kif ukoll jekk int nieqsa xi gradi jew xi ħaġa 1537 01:11:41,760 --> 01:11:43,060 ma jidhirx li jagħmel sens. 1538 01:11:43,060 --> 01:11:43,720 Come lili. 1539 01:11:43,720 --> 01:11:44,830 1540 01:11:44,830 --> 01:11:48,830 >> Stajt ġiet super kburi int guys diġà, hekk jżomm dan aġġornat. 1541 01:11:48,830 --> 01:11:50,640 U jkollhom mistrieħ tajba tal-ġimgħa tiegħek. 1542 01:11:50,640 --> 01:11:53,440 Jien ċert I ser tara xi tal inti fil ħinijiet tal-uffiċċju. 1543 01:11:53,440 --> 01:11:55,414