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[Powered by Google Translate] DAVID J. Malan: Kull dritt, dan huwa CS50, u dan huwa l-

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bidu ta 'ġimgħatejn.

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Grazzi.

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Let us tibda hawn bil-telefonata.

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Jien ser dial 617-BUG-CS50.

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CS50: Dan huwa CS50.

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Għal Boy Shuttle, istampa 1.

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Biex tibda fuq, agħfas 9.

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DAVID J. Malan: Hekk hu qal għal Boy Shuttle, l-istampa 1.

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Allura aħna qed tmur għall-istampa 1.

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CS50: X'inhu l-oriġini tiegħek?

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Għal quad, l-istampa 1.

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Mather, l-istampa 2.

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Boylston, l-istampa 3.

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Lamont, l-istampa 4.

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Mem Hall, l-istampa 5.

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Biex tibda fuq, agħfas 0.

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DAVID J. Malan: Aħna ser tinsisti 1 għall quad.

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CS50: shuttle jmiss tħalli dan ħafna minuta PM 1:10, u

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imbagħad fi 1:20 PM, 01:30, 01:40.

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Dan huwa CS50.

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>> DAVID J. Malan: Allura dan huwa vuċi CS50 s.

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U huwa eżempju ta 'l-xorta ta' proġetti finali, għall-

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eżempju, inti tista 'gidma off lejn

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l-aħħar tas-semestru.

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Per eżempju, din shuttleboy.cs50.net teżisti -

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attwalment proġett li I-ewwel kiteb wara li tieħu CS51

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lura meta I kien undergraduate.

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U l-ispirazzjoni hawn kien lura mbagħad, kull ma kellhom kien

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l-iskedi tax-shuttle bus stampati, u hemm l-ebda

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kunċett ta 'tfittex affarijiet up online.

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U għalhekk jien tip ta 'ħamiema f'wieħed weekend, jitferra permezz tal-

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stampati iskeda, u portati lill programm tal-kompjuter.

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Fiż-żmien, il-programm tal-kompjuter ġara li tkun bil-miktub

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fil C. U inti fil-fatt dam mill Boy Shuttle ittajpjar fuq

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Teptip fil-pront bħal aħna kont qed tagħmel s'issa.

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Imma matul is-snin, huwa evolvew instant

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messaġġi bot.

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Huwa evolvew aktar reċentement fis din il-websajt, fi

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SMS bbażata fuq għodda, kif ukoll fis din l-għodda vuċi bbażata fuq.

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U dan huwa li ħjiel fuq l-xorta ta 'affarijiet li inti tista'

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tagħmel għalik innifsek sa tmiem semestru tal.

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>> Per eżempju, hemm, il-verżjoni SMS tal Boy shuttle jiġri

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biex jopera kif ġej.

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Jekk, fuq il-mobile phone tiegħek, inti tibgħat messaġġ test li 41,411 u

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mbagħad jibgħat l-sboy simbolu speċjali, għall-Boy Shuttle,

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segwit minn A u B, fejn A huwa l-oriġini u B huwa

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destinazzjoni -

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per eżempju, Boylston Ispazju Quad -

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dak li għandek terġa 'lura fi ftit sekondi huwa test

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Messaġġ mill Boy Shuttle tghidlek eżattament meta l-

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shuttles li ġejjin huma, minn dan il-punt A li jmorru għal dak

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punt B.

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U dan huwa eżempju aktar ġenerali ta 'dak magħruf bħala

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jużaw API.

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>> Għalhekk per eżempju, dan hawnhekk hija biss shuttleboy.cs50.net, il-

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attwali fuq l-internet Inkarnazzjoni ta 'dan.

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Iżda d-data li jenfasizza apps dan u oħrajn li CS50

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żviluppat huma kollha esposti għal kulħadd hawn fil-forma

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ta 'APIs, interfaces ta' programmazzjoni applikazzjoni.

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U dan huwa biss mod fancy ta 'tgħid li n-nies jixtiequ aħna fuq

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l-Internet u oħrajn jkunu qattgħu xi żmien ħolqien

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software li tista 'tuża biex grab data minn għandna u

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imbagħad jibnu l-applikazzjonijiet tiegħek fuq nett

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ta 'dak is-sett tad-dejta.

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Għalhekk per eżempju, dan il-shuttle Boy API paġna hawn, li

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jiġri li jkun fil-manwal CS50, essenzjalment dokumenti

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kif inti tista 'tmur dwar tistaqsi CS50 servers għal data.

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Per eżempju, jekk int familjari ma 'CSV fajls, comma

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separati valuri, dawn huma biss it-tip ta 'malajr u maħmuġin

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Excel-like fajls.

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Allura inti tista 'tistaqsi Boy Shuttle għall kollha tad-data fuq kollha ta' l-

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djar u koordinati GPS tagħhom, u int ser tingħata

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lura, essenzjalment, spreadsheet bħal dik li

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inti tista 'mbagħad jaqra fi programm tal tiegħek u mbagħad

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jiġġeneraw riżultati, bħall-Boy Shuttle innifsu

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jiġri li tkun qiegħda tagħmel.

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Għal dawk aktar familjari, rappreżentazzjonijiet tad-data aktar moderni

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jinkludu JSON, Notazzjoni Għan JavaScript.

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Xi ħaġa se terga 'lura lilek lejn

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l-aħħar tas-semestru.

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>> Iżda għal darb'oħra, dan huwa biss wieħed minn ħafna ta 'APIs stess CS50 s.

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U l-ħaġa eċċitanti hija issa, dawn il-ġranet, Facebook u

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Twitter u Google u pretty ħafna kull website popolari out

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kien hemm xi tip ta 'API, li jfisser li jekk inti taqra l-

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dokumentazzjoni dwar il-websajt tagħhom, inti jiffirmaw għal

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kont, inti tista 'mbagħad tibda bil-miktub tas-softwer fuq quċċata ta'

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kwalunkwe għodda jew data li l-kumpanija hemm tipprovdi.

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U għalhekk wieħed mill fellows tagħna stess ta 'tagħlim ftit snin lura

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kiteb verżjoni Mac ta 'dan.

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Allura fil-link intitolat Mac hawn fuq quċċata xellug, inti tista 'attwalment

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tniżżel widget Mac OS li timxi fuq Mac tiegħek biex jagħmlu l-

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istess tipi ta 'affarijiet.

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Allura dan kollu dwar il-bini fuq quċċata ta 'settijiet ta' data bħal dawn.

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Iżda aktar fuq dan lejn it-tmiem tas-semestru.

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>> Mela ejja adsa malajr reali biex bug, biss biex tikseb it-tip ta

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affarijiet msaħħna llum, u jaħsbu lura fuq xi wħud mill-

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affarijiet ħarisna lejn ġimgħa li għaddiet.

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B'mod partikolari, let me imorru quddiem u iġbed up, ngħidu aħna,

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dan l-eżempju hawn.

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Buggy1.c, dan huwa disponibbli fuq il-websajt tal-kors tal jekk youd

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simili li niżżlu u poke madwar yourself.

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Imma ejja zoom hawn fuq f'dan il-programm pjuttost qasir, u biss

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terġa super fast ta 'xi wħud mill-moduli bażiċi li

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aħna verament huma se biss tibda tieħu għall mogħtija.

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>> Allura l-għalf blu, fil-linji 1 sa 9, huma biss

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softball mistoqsijiet.

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Allura dawn huma biss kummenti.

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Huma jkollhom l-ebda tifsira funzjonali.

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Iżda dawn qed kummenti fis-sens li dawn qed jinnota li

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Jiena, il-bniedem, magħmul għal myself sabiex fil lecture u wara

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lecture, I jistgħu attwalment tiftakar dak dan il-programm

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ma mingħajr ma jaqra permezz ta 'dan linja b'linja u

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recreating istorja fil-fehma tiegħi.

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Barra minn hekk, jekk I-idejn dan il-programm lil xi ħadd ieħor simili

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inti, huwa ħafna aktar ċar li inti, minħabba kummenti bħal dan,

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dak il-programm fil-fatt tagħmel, jew għall-inqas dak il-

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programm suppost li tkun qiegħda tagħmel.

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Jew le huwa korrett hija kwistjoni oħra għal kollox.

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Issa, fis-C, multi-linja kummenti, ifakkar li fuq il-linja

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wieħed hawn huwa s-simbolu magic, / *.

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Dan ifisser hawnhekk jidħol l-bidu ta 'kumment.

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U xejn kwistjonijiet sakemm inti jilħqu t-tmiem terminatur,

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li huwa * /, l-oppost.

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Allura l-fatt li għandi 80-xi stilla fard hawn minn

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xellug għal-lemin huwa verament ftit dettall estetika.

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Hija għandha l-ebda tifsira funzjonali.

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>> Issa kif madwar linja 11?

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X'jagħmel din do f'termini laymans?

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X'hemm li?

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UDJENZA: Jinkludi l-istandard.

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DAVID J. Malan: OK, tajba.

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Għalhekk tinkludi l-librerija stdio.h.

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Allura dak ma jfisser?

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Ukoll, ġewwa dan il-fajl, stdio.h, huma mazz sħiħ ta '

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funzjoni dikjarazzjonijiet -

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jiġifieri, il-kodiċi li xi ħadd ieħor kiteb.

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U eżempju perfett ta 'funzjoni li s iddikjarata

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stdio.h huwa -

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li favorit minn issa?

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Allura printf, wieħed mill-aktar komuni għall-użu, ċertament

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kmieni, minn dik librerija hemm.

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Jekk I jeskludu dik il-linja tal-kodiċi, clang se Yell

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fil lili xi ħaġa dwar l-użu ta 'simbolu mhux iddikjarat.

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Xi ħaġa mhux iddikjarat huwa probabbilment l-keyword, minħabba li

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aħna ma infurmaw lill-kumpilatur dak printf jistenna

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simili sakemm aħna jinkludu dik il-linja.

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U aktar l isfel għall-Dinja, verament, dak li linja huwa qal huwa

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jiftħu dan il-fajl, stdio.h, kull fejn huwa fuq il-tal-server

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hard drive, jew hard drive, l-apparat, u kopja-paste dan

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hemm dritt fil-fajl tiegħi, mingħajr tiegħi

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jkollhom jagħmlu dan manwalment.

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>> Issa, ladarba irridu jiksbu l isfel hawn biex prinċipali, qabel twil aħna ser tibda

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teasing apparti huwa null dak int u dak li.

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Iżda għal issa, ejja nħarsu lejn it-tliet linji

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fi żmien 15 permezz 17.

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Dan here I pretensjoni bħala Buggy.

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Linja 7 fil-kummenti tiegħi jgħid "Jekk print 10

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asteriski iżda ma. "Għaliex ma dan ma print, fil-fatt,

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10 stilla bħal dawn?

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UDJENZA: [inaudible].

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DAVID J. Malan: Eżattament.

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Allura avviż li aħna qed jibdew jgħoddu minn 0.

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U dan huwa attwalment konvenzjoni fl-ipprogrammar u l-

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xjenza tal-kompjuter aktar ġenerali, li jibda jgħodd

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minn 0 minflok 1.

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U dan verament ftit joħroġ mill-fatt li, għall-

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Pereżempju, meta kellna tmien persuni up fuq l-istadju, meta

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ebda wieħed kien jgħollu naħa tagħhom, kienu

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kollha żerijiet effettiv.

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U dan huwa biss tip ta 'konvenzjoni tal-kompjuter hekk,

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għalhekk, biex jibdew jingħaddu minn 0.

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Jekk dan huwa l-anqas numru inti tista jirrappreżentaw fil binarja.

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>> Allura hawnhekk konna beda initializing i għal 0.

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Imxejna stabbilit i ugwali għal 0.

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Imma mbagħad I magħmula dan l-iżball hawn, qal i huwa inqas jew

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ugwali għal 10.

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Imma jekk inti taħseb li permezz ta ', jekk nibda fi 0 u mbagħad mmur

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sa 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, Jien fil-fatt ser

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jistampa 11 istilel għall-iskrin, għaliex stajt marret up

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għal u ugwali għal 10.

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Allura l-jiffissaw faċli hawn allura huwa dak?

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UDJENZA: [inaudible].

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DAVID J. Malan: Just bidla għal inqas minn.

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Jekk int verament tixtieq, inti tista 'tagħmel dan.

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Iżda b'mod ġenerali, li l-frowned fuq.

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U għalhekk jibda jgħodd minn 0 hija biss xi ħaġa inti għandek

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tipikament jidraw.

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Issa, dak dwar dan kollu kostruzzjoni u fih innifsu?

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Dan line 15 demarks a għal loop.

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Allura għal mhix funzjoni.

192
00:08:12,510 --> 00:08:13,640
Huwa biss dikjarazzjoni.

193
00:08:13,640 --> 00:08:16,180
Huwa tibni looping, bħal rajna fil Scratch.

194
00:08:16,180 --> 00:08:17,600
U għandu tliet partijiet.

195
00:08:17,600 --> 00:08:19,740
Avviż li hemm il-parti 1 li

196
00:08:19,740 --> 00:08:21,350
l-xellug tal-punt u virgola.

197
00:08:21,350 --> 00:08:24,200
Hemm il-parti tan-nofs bejn il-semicolons 2.

198
00:08:24,200 --> 00:08:26,250
U allura hemm il-parti tal-lemin lejn il-lemin

199
00:08:26,250 --> 00:08:27,640
tat-virgola 2.

200
00:08:27,640 --> 00:08:31,822
Issa, l-ewwel minn dawn jagħmel xiex?

201
00:08:31,822 --> 00:08:33,679
UDJENZA: [inaudible].

202
00:08:33,679 --> 00:08:34,270
DAVID J. Malan: Lura hemmhekk?

203
00:08:34,270 --> 00:08:34,816
Yeah?

204
00:08:34,816 --> 00:08:35,980
UDJENZA:. Inizjalizzazzjoni

205
00:08:35,980 --> 00:08:36,850
>> DAVID J. Malan: inizjalizzazzjoni.

206
00:08:36,850 --> 00:08:37,840
Allura dak li jfisser dan?

207
00:08:37,840 --> 00:08:40,690
Aħna jkunu ddikjaraw varjabbli imsejjaħ i.

208
00:08:40,690 --> 00:08:43,840
Huwa ta 'int tip, għaliex stajt speċifikat int i.

209
00:08:43,840 --> 00:08:46,470
U jien initializing i għall-valur ta '0.

210
00:08:46,470 --> 00:08:47,730
Allura x'hemm dan verament tgħid?

211
00:08:47,730 --> 00:08:50,680
Huwa effettivament tgħid li l-kompjuter ħej, agħti lili biżżejjed

212
00:08:50,680 --> 00:08:53,660
, memorja RAM biżżejjed, biex jitwaħħal numru, u mbagħad iwettqu l-

213
00:08:53,660 --> 00:08:56,130
Numru 0 f'dak blokki ta 'RAM.

214
00:08:56,130 --> 00:08:59,100
U bħala twarrib, kemm hu kbir huwa int tipikament, inqas minn ġewwa

215
00:08:59,100 --> 00:09:00,280
tat-tagħmir?

216
00:09:00,280 --> 00:09:01,000
UDJENZA: 32 bit.

217
00:09:01,000 --> 00:09:01,670
DAVID J. Malan: 32 bits.

218
00:09:01,670 --> 00:09:04,890
Allura dan ifisser jagħtu me 32 bits, magħrufa bħala 4 bytes,

219
00:09:04,890 --> 00:09:07,250
u tpoġġi l-0 valur fiha, li huwa pjuttost faċli minħabba

220
00:09:07,250 --> 00:09:09,110
hija biss mezzi msemmija l-bits għal 0.

221
00:09:09,110 --> 00:09:11,690
>> Allura issa, it-tieni parti hawnhekk huwa l-kundizzjoni.

222
00:09:11,690 --> 00:09:14,590
U l-kundizzjoni, hekk kif tissuġġerixxi l-isem, huwa dak li huwa kkontrollat

223
00:09:14,590 --> 00:09:18,100
ġdid u għal darb'oħra u għal darb'oħra dwar jekk huwa veru jew falza.

224
00:09:18,100 --> 00:09:21,410
Allura dan huwa biss qal jagħmlu l-linji ta 'kodiċi -

225
00:09:21,410 --> 00:09:23,950
jiġifieri linja 16, għaliex dak l-uniku wieħed indentati

226
00:09:23,950 --> 00:09:24,820
taħt -

227
00:09:24,820 --> 00:09:26,980
sakemm i huwa inqas minn 10.

228
00:09:26,980 --> 00:09:30,520
U wara kull iterazzjoni permezz ta 'dan loop, jagħmlu l-

229
00:09:30,520 --> 00:09:33,840
incrementation, li f'dan il-każ huwa i + +.

230
00:09:33,840 --> 00:09:35,580
Issa, dan ma għandhom ikunu i + +.

231
00:09:35,580 --> 00:09:37,610
Dan jista 'jkun i -.

232
00:09:37,610 --> 00:09:39,860
Imma jekk jien għamilt dan, dak li l-imġieba għaddej

233
00:09:39,860 --> 00:09:41,370
li jkunu ta 'dan il-programm?

234
00:09:41,370 --> 00:09:42,290
UDJENZA: Huwa ser tkun loop infinita.

235
00:09:42,290 --> 00:09:44,060
DAVID J. Malan: Huwa ser jkun hemm xi tip ta 'loop infinita,

236
00:09:44,060 --> 00:09:47,720
sakemm aħna nikseb xxurtjati wara t-2 negattiv biljun jew hekk.

237
00:09:47,720 --> 00:09:51,320
Forsi l-affarijiet se perimetrika, biss min-natura tal-finita

238
00:09:51,320 --> 00:09:53,930
numru ta 'bits li għandna allokati għal int.

239
00:09:53,930 --> 00:09:56,270
Iżda huwa ċertament se jtenni ferm aktar minn 10 u

240
00:09:56,270 --> 00:09:58,630
ċertament aktar minn 11-il darba hawn.

241
00:09:58,630 --> 00:10:02,240
>> U issa, biss bħala twarrib, tirrealizza li i + + u i -

242
00:10:02,240 --> 00:10:04,420
huma verament ftit zokkor sintattiku.

243
00:10:04,420 --> 00:10:07,210
Huwa biss notazzjoni shorthand għal x'hemm ftit aktar

244
00:10:07,210 --> 00:10:08,720
espliċitament bil-miktub kif ġej:

245
00:10:08,720 --> 00:10:11,200
i = i + 1.

246
00:10:11,200 --> 00:10:13,460
Dan huwa identiku għall i + +.

247
00:10:13,460 --> 00:10:15,860
Hija biss it-tip ta 'jistenna prettier ngħid i + +.

248
00:10:15,860 --> 00:10:17,490
Huwa aktar konċiża, aktar leġġibbli.

249
00:10:17,490 --> 00:10:19,030
U hekk ħafna nies li minflok.

250
00:10:19,030 --> 00:10:21,840
Iżda din hija identika funzjonalment li

251
00:10:21,840 --> 00:10:22,900
dak li aħna biss raw.

252
00:10:22,900 --> 00:10:27,770
Allura fil-qosor, l-jiffissaw malajr hawnhekk huwa biss biex jgħidu jtenni i

253
00:10:27,770 --> 00:10:30,690
minn 0 it-triq kollha sa inqas minn 10.

254
00:10:30,690 --> 00:10:32,700
U allura aħna ser tabilħaqq tikseb 10 istilel.

255
00:10:32,700 --> 00:10:33,430
>> Mela ejja jippruvaw dan.

256
00:10:33,430 --> 00:10:35,310
Let me tiftaħ il-terminal fil-qiegħ.

257
00:10:35,310 --> 00:10:37,420
Let me jmorru fil-direttorju li dan huwa pulzieri

258
00:10:37,420 --> 00:10:40,030
U jien ser josservawha manwalment bl clang għal issa.

259
00:10:40,030 --> 00:10:44,880
U jien ser jiġbor dan bħala buggy1.c, Ikteb.

260
00:10:44,880 --> 00:10:50,280
U issa buggy1, għaliex hemm ebda tali file jew direttorju

261
00:10:50,280 --> 00:10:52,026
imsejħa buggy1?

262
00:10:52,026 --> 00:10:53,850
UDJENZA: [inaudible].

263
00:10:53,850 --> 00:10:54,240
DAVID J. Malan: Yeah.

264
00:10:54,240 --> 00:10:55,420
Allura huwa attwalment imsejħa a.out.

265
00:10:55,420 --> 00:10:57,480
Mela recall jekk inti biss run clang, huwa clang fejn l-

266
00:10:57,480 --> 00:11:00,420
kompilatur, u inti ma tispeċifika l-isem li trid

267
00:11:00,420 --> 00:11:03,550
jagħtu lill-programm tiegħek, li għaddej biex default għall a.out.

268
00:11:03,550 --> 00:11:05,030
Mela fil-fatt jekk nagħmel ls -

269
00:11:05,030 --> 00:11:05,510
oops.

270
00:11:05,510 --> 00:11:07,680
U jien didn't - il-kwistjoni iswed u abjad wħud

271
00:11:07,680 --> 00:11:08,840
inti jiffaċċjaw ġie ffissat.

272
00:11:08,840 --> 00:11:10,670
Iżda let me do dan.

273
00:11:10,670 --> 00:11:14,570
Hemm aħna għandna a.out fuq in-naħa tax-xellug hemm.

274
00:11:14,570 --> 00:11:17,360
Allura aħna għandna jiddekorri a.out minflok buggy1.

275
00:11:17,360 --> 00:11:19,140
>> So let me imorru quddiem u jagħmlu dan.

276
00:11:19,140 --> 00:11:22,840
. A.out /, Ikteb.

277
00:11:22,840 --> 00:11:26,160
U jien apparentement ma tagħmel dak?

278
00:11:26,160 --> 00:11:26,620
UDJENZA: Save.

279
00:11:26,620 --> 00:11:27,390
DAVID J. Malan: Save fajl tiegħi.

280
00:11:27,390 --> 00:11:31,520
Allura li huwa faċilment solvuti billi jolqot S Kontroll, jew sejrin lejn

281
00:11:31,520 --> 00:11:33,450
File, Save, bħal fil-programmi l-aktar.

282
00:11:33,450 --> 00:11:36,360
Let me jinżlu hawn, ċar l-iskrin, run mill-ġdid.

283
00:11:36,360 --> 00:11:37,960
U hemm għadu bug.

284
00:11:37,960 --> 00:11:41,618
Allura dak li qed jiġri -

285
00:11:41,618 --> 00:11:42,980
UDJENZA: Inti ma tiġbor.

286
00:11:42,980 --> 00:11:44,040
DAVID J. Malan: Ah, tajba.

287
00:11:44,040 --> 00:11:45,010
I ma josservawha.

288
00:11:45,010 --> 00:11:47,250
Bħal idjota, jien tħares lejn il-kodiċi biex tara x'hemm ħażin.

289
00:11:47,250 --> 00:11:51,275
Allura clang buggy1.c, issa a.out.

290
00:11:51,275 --> 00:11:52,640
U phew, ffrankati.

291
00:11:52,640 --> 00:11:55,090
>> Għalhekk jistenna ftit ikrah għaliex hemm l-ebda linja ġdida

292
00:11:55,090 --> 00:11:55,970
kullimkien fil-programm.

293
00:11:55,970 --> 00:11:57,390
Iżda għal darb'oħra, dan huwa biss dettall estetika.

294
00:11:57,390 --> 00:11:59,430
U għall-inqas jekk aħna għadd dawk barra, għandna

295
00:11:59,430 --> 00:12:01,160
issa tara 10-il stilla bħal dawn.

296
00:12:01,160 --> 00:12:03,260
Ukoll, dak dwar din it-tieni warm-up eżempju?

297
00:12:03,260 --> 00:12:07,750
Għalhekk fl buggy2, I jsostnu li din il-verżjoni, wisq, se print

298
00:12:07,750 --> 00:12:10,110
10 stilla, waħda għal kull linja.

299
00:12:10,110 --> 00:12:12,340
Allura dan iż-żmien, I għandhom karattru newline, biss biex jagħmlu

300
00:12:12,340 --> 00:12:13,520
affarijiet ftit prettier.

301
00:12:13,520 --> 00:12:15,410
Iżda minflok dak I nikseb hija din.

302
00:12:15,410 --> 00:12:19,590
So let me do buggy2.c clang, Ikteb.

303
00:12:19,590 --> 00:12:21,790
Issa huwa għal darb'oħra imsejjaħ a.out.

304
00:12:21,790 --> 00:12:23,130
Ikteb.

305
00:12:23,130 --> 00:12:26,900
I biss tara linja waħda ġdida, biss il-linja l-ġdida ħafna aħħar li

306
00:12:26,900 --> 00:12:29,370
jiċċaqlaq fil-pront tiegħi mal-linja li jmiss.

307
00:12:29,370 --> 00:12:32,660
And yet b'mod ċar stajt ġiet istampar *, imbagħad linja ġdida,

308
00:12:32,660 --> 00:12:33,990
*, Imbagħad linja ġdida.

309
00:12:33,990 --> 00:12:35,490
Imma x'inhu l-bug hawn?

310
00:12:35,490 --> 00:12:35,974
Yeah?

311
00:12:35,974 --> 00:12:37,224
UDJENZA: [inaudible].

312
00:12:39,850 --> 00:12:40,470
>> DAVID J. Malan: Eżattament.

313
00:12:40,470 --> 00:12:44,110
Allura b'differenza xi lingwi, bħall Python, fejn indentazzjoni

314
00:12:44,110 --> 00:12:46,030
fil-fatt għandha tifsira funzjonali, b'mod

315
00:12:46,030 --> 00:12:47,150
lingwa bħal C -

316
00:12:47,150 --> 00:12:49,140
kif aħna ser tara, PHP, JavaScript -

317
00:12:49,140 --> 00:12:51,940
l-indentazzjoni huwa verament biss għall-benefiċċju bniedem ".

318
00:12:51,940 --> 00:12:55,690
Allura l-fatt li stajt indentati linja 16 u 17 jistenna kbira,

319
00:12:55,690 --> 00:12:57,530
iżda ma jkollu ebda tifsira funzjonali hawn.

320
00:12:57,530 --> 00:13:00,700
Jekk irrid żewġ linji li teżegwixxi bħala parti mill-għar

321
00:13:00,700 --> 00:13:05,140
loop, imbagħad I għandhom jehmżu magħhom fl ċineg kaboċċi billi tagħmel dan.

322
00:13:05,140 --> 00:13:08,540
Tista 'biss tnaqqas l-kantuniera u jħalli barra l-braces kaboċċi jekk

323
00:13:08,540 --> 00:13:10,036
x'inhu l-każ?

324
00:13:10,036 --> 00:13:10,410
UDJENZA: Just linja waħda.

325
00:13:10,410 --> 00:13:11,130
DAVID J. Malan: Eżatt linja waħda.

326
00:13:11,130 --> 00:13:15,280
Hekk li jinsab biss it-tip ta 'tip sabiħ ta' dettall sintassi sabiex

327
00:13:15,280 --> 00:13:17,900
inti ma jaħlux ħin kitba tliet linji, li tnejn minnhom huma

328
00:13:17,900 --> 00:13:20,040
ċineg kaboċċi, biss jiktbu linja waħda tal-kodiċi.

329
00:13:20,040 --> 00:13:21,650
Imma jekk ikollok tnejn jew aktar linji, aħna

330
00:13:21,650 --> 00:13:22,860
tabilħaqq bżonn tagħmel dan.

331
00:13:22,860 --> 00:13:24,210
>> Allura issa let me jiffrankaw dan.

332
00:13:24,210 --> 00:13:27,140
Let me imorru quddiem u jerġa 'jsir clang.

333
00:13:27,140 --> 00:13:31,375
Imbagħad let me terġa 'ssir a.out, u issa I tikseb minnhom wieħed għal kull linja.

334
00:13:31,375 --> 00:13:33,670
Issa, a.out darb'oħra huwa tip ta 'isem dumb għal programm.

335
00:13:33,670 --> 00:13:37,500
Kif nista 'nkun naf clang biex effettivament tagħti me isem ta' fajl

336
00:13:37,500 --> 00:13:39,820
li l-aktar faċli għall-utent, bħall buggy2 stess?

337
00:13:43,200 --> 00:13:44,466
A ftit aktar ċar?

338
00:13:44,466 --> 00:13:45,220
UDJENZA: [inaudible].

339
00:13:45,220 --> 00:13:47,810
DAVID J. Malan: OK, so I jistgħu attwalment jieħdu l-ħafna

340
00:13:47,810 --> 00:13:51,000
faċli għall-utent shortcut u biss jiktbu jagħmlu buggy2.

341
00:13:51,000 --> 00:13:53,840
Jien ma jispeċifikawx. Ċ f'dan il-każ, u hit Ikteb.

342
00:13:53,840 --> 00:13:58,530
U dak li jagħmel ma huwa jikkompila buggy2.c għalija billi

343
00:13:58,530 --> 00:14:00,260
titlob clang biex tagħmel dan.

344
00:14:00,260 --> 00:14:05,100
Speċifikament, huwa jappella clang, din tmur clang tuża b'mod aktar

345
00:14:05,100 --> 00:14:08,540
kmand tal-linja argumenti jew swiċċijiet minn I attwalment bżonn.

346
00:14:08,540 --> 00:14:11,270
Fil-ħin, aħna ser terga 'lura għal dak li dawn kollha diversi

347
00:14:11,270 --> 00:14:13,810
espressjonijiet hyphenated cryptic mezzi.

348
00:14:13,810 --> 00:14:16,910
Iżda għal issa, li jinsab biss iffrankar lili il-problemi ta '

349
00:14:16,910 --> 00:14:19,600
wara li tiftakar u jkollhom tip out kollha ta 'dawk

350
00:14:19,600 --> 00:14:21,150
espressjonijiet hyphenated varji.

351
00:14:21,150 --> 00:14:23,240
U l-rasu ta 'dan, finalment, huwa

352
00:14:23,240 --> 00:14:25,900
li issa għandi buggy2.

353
00:14:25,900 --> 00:14:27,480
Jekk irrid li tagħmel dan manwalment, għalkemm, jiena

354
00:14:27,480 --> 00:14:28,775
tista 'minflok tagħmel dan -

355
00:14:28,775 --> 00:14:34,110
clang-o buggy2 u mbagħad buggy2.c.

356
00:14:34,110 --> 00:14:37,980
U li se simili tagħti me a inkartament imsejjaħ buggy2.

357
00:14:37,980 --> 00:14:39,710
>> Allura fil-qosor, clang l-kumpilatur.

358
00:14:39,710 --> 00:14:43,080
Agħmel hija biss għodda faċli għall-utent li aħna ser tkun qed tuża aktar

359
00:14:43,080 --> 00:14:44,420
u aktar, għaliex hija biss jibda

360
00:14:44,420 --> 00:14:47,330
tissimplifika l-affarijiet għalina.

361
00:14:47,330 --> 00:14:49,430
U aħna ritorn 0, fl-aħħar.

362
00:14:49,430 --> 00:14:51,890
Għal issa, biss għaliex, imma aħna ser tibda teasing dik il-parti

363
00:14:51,890 --> 00:14:52,930
illum u nhar l-Erbgħa.

364
00:14:52,930 --> 00:14:55,560
Kwalunkwe mistoqsijiet dwar kwalunkwe ta 'dan?

365
00:14:55,560 --> 00:14:56,450
Yeah?

366
00:14:56,450 --> 00:14:58,234
UDJENZA: [inaudible]

367
00:14:58,234 --> 00:15:00,020
ls fil kwotazzjonijiet hemmhekk?

368
00:15:00,020 --> 00:15:01,710
DAVID J. Malan: OK.

369
00:15:01,710 --> 00:15:05,880
Meta I ls ittajpjat fil-kwotazzjonijiet, li kien me tagħmel xi magic

370
00:15:05,880 --> 00:15:07,160
wara l-kwinti biex jiffissaw bug.

371
00:15:07,160 --> 00:15:09,370
I nesa, bħal aħna kont qed javżak ħafna minnkom fuq l-

372
00:15:09,370 --> 00:15:11,600
diskussjoni bordijiet, li jagħmlu -

373
00:15:11,600 --> 00:15:17,220
aħna ser nagħmlu dan issa - sudo yum-y aġġornament appliance50.

374
00:15:17,220 --> 00:15:19,790
Whoops, li thats spelt dritt.

375
00:15:19,790 --> 00:15:23,240
Allura l-appliance hija bħal sistema operattiva.

376
00:15:23,240 --> 00:15:25,650
Huwa running din is-sistema operattiva imsejħa Fedora.

377
00:15:25,650 --> 00:15:27,450
U issa minħabba l-konnessjoni tiegħi internet bil-mod, stajt

378
00:15:27,450 --> 00:15:28,260
verament ser jiġu maħsula permezz dan.

379
00:15:28,260 --> 00:15:31,620
Allura running aġġornament yum sudo, kif aħna jgħidlek biex tagħmel fil-

380
00:15:31,620 --> 00:15:34,080
sett problema, essenzjalment simili taħdem aġġornamenti awtomatiċi

381
00:15:34,080 --> 00:15:35,420
fil Mac OS jew Windows.

382
00:15:35,420 --> 00:15:37,280
U r-raġuni għat-tmexxija dan fil-bidu nett tal-

383
00:15:37,280 --> 00:15:39,640
Sett problema għaliex meta ħloqna l-appliance, I

384
00:15:39,640 --> 00:15:42,480
messed up, u I aċċidentalment magħmula kollha ta 'programmi tiegħek ħarsa

385
00:15:42,480 --> 00:15:45,210
iswed fuq skrin iswed, u huwa għalhekk li int ma jaraw lilhom

386
00:15:45,210 --> 00:15:45,860
kontumaċja.

387
00:15:45,860 --> 00:15:48,020
Iżda l-aħħar verżjoni ta 'l-appliance jiffissa dan.

388
00:15:48,020 --> 00:15:50,500
U jien ser jiffissaw li matul waqfa ladarba I jkollhom Internet

389
00:15:50,500 --> 00:15:51,280
konnettività.

390
00:15:51,280 --> 00:15:54,630
>> Allura l-kwotazzjonijiet biss ġlud żball tiegħi, ħafna diskret,

391
00:15:54,630 --> 00:15:55,730
apparentament.

392
00:15:55,730 --> 00:15:56,980
Mistoqsijiet oħra?

393
00:15:59,750 --> 00:16:00,668
Iva?

394
00:16:00,668 --> 00:16:02,012
UDJENZA: Fejn ma jagħmlu jiġu minn?

395
00:16:02,012 --> 00:16:03,810
[Inaudible]

396
00:16:03,810 --> 00:16:04,280
DAVID J. Malan: Mistoqsija tajba.

397
00:16:04,280 --> 00:16:05,460
Fejn ma jiġu minn tagħmel?

398
00:16:05,460 --> 00:16:09,390
Dan huwa programm Linux li ilha teżisti għal ħafna snin, sakemm

399
00:16:09,390 --> 00:16:10,570
qabel CS50.

400
00:16:10,570 --> 00:16:12,930
U niġu ma 'sistema operattiva bħal Fedora.

401
00:16:12,930 --> 00:16:14,830
Dan ma jaqax mill-bibljoteka CS50.

402
00:16:14,830 --> 00:16:17,560
Fil-fatt, l-uniċi affarijiet li ġejjin mill-bibljoteka CS50

403
00:16:17,560 --> 00:16:20,470
s'issa, li aħna stajt tidher, huma GetString, GetInt, kollha ta '

404
00:16:20,470 --> 00:16:25,550
dawk Get funzjonijiet, u l-sekwenza kelma, u sa ċertu

405
00:16:25,550 --> 00:16:26,575
limitu, il-kelma bool.

406
00:16:26,575 --> 00:16:29,180
Iżda aħna ser tease li apparti meta aħna adsa fis-CS50

407
00:16:29,180 --> 00:16:30,580
apparat innifsu.

408
00:16:30,580 --> 00:16:32,820
>> Allura iva, mistoqsija waħda aktar hawn.

409
00:16:32,820 --> 00:16:36,636
UDJENZA: Meta inti qal tagħmel u mbagħad Buggy, kif ma 'l-

410
00:16:36,636 --> 00:16:39,980
kompjuter taf [inaudible]?

411
00:16:39,980 --> 00:16:40,520
DAVID J. Malan: Mistoqsija tajba.

412
00:16:40,520 --> 00:16:43,830
Allura meta inti biss run tagħmel buggy1 jew jagħmlu buggy2, kif

413
00:16:43,830 --> 00:16:45,220
ma tagħmel taf?

414
00:16:45,220 --> 00:16:49,900
Allura fil-kontumaċja, jekk inti tip tagħmel buggy1, jagħmlu jistenna għal

415
00:16:49,900 --> 00:16:52,330
fajl imsejjaħ buggy1.c.

416
00:16:52,330 --> 00:16:55,570
U allura tesegwixxi l-kmandi clang xierqa,

417
00:16:55,570 --> 00:17:00,380
b'hekk tiġi sorpassata l-fajl default imsejħa a.out.

418
00:17:00,380 --> 00:17:03,670
Fil-fatt, jekk inħarsu lejn dak li jagħmel, dak -

419
00:17:03,670 --> 00:17:04,839
ejja nieqaf dan.

420
00:17:04,839 --> 00:17:09,530
Jekk inħarsu lejn dak li jagħmlu kien fil-fatt tagħmel, tagħmel buggy2,

421
00:17:09,530 --> 00:17:10,470
huwa diġà aġġornata.

422
00:17:10,470 --> 00:17:13,020
So let me tneħħi l-kmand rm, il-

423
00:17:13,020 --> 00:17:14,319
Programm I kiteb qabel.

424
00:17:14,319 --> 00:17:17,319
Ittajpjar Y-E-S li tikkonferma li nixtieq li tneħħiha.

425
00:17:17,319 --> 00:17:20,480
Jekk I issa ma tagħmel, avviż li din il-linja twila ħafna,

426
00:17:20,480 --> 00:17:22,980
hemm dan aħħar ħaġa hawn, o buggy2.

427
00:17:22,980 --> 00:17:26,959
Kollha jagħmlu qed tagħmel hija tgħaddi dan l-argument, biex ngħidu hekk, biex

428
00:17:26,959 --> 00:17:29,665
Clang, I hekk li ma jkollhomx it-tip myself.

429
00:17:29,665 --> 00:17:32,660
>> Kull dritt, hekk ftit malajr ta amministrattiva

430
00:17:32,660 --> 00:17:33,470
Avviżi.

431
00:17:33,470 --> 00:17:36,940
Allura għal sezzjonijiet, li uffiċjalment beda din ġejjin

432
00:17:36,940 --> 00:17:38,970
Ħadd, inti ser dejjem tixtieq li tressaq, jekk

433
00:17:38,970 --> 00:17:40,120
għandek wieħed, laptop.

434
00:17:40,120 --> 00:17:42,570
Jekk inti ma għandekx laptop, ma jilħqu lili mill

435
00:17:42,570 --> 00:17:43,580
twaqqa email.

436
00:17:43,580 --> 00:17:44,810
U aħna ser insemmu workflow.

437
00:17:44,810 --> 00:17:47,100
Dak li ġeneralment inti ser issib fis-sezzjoni hija li dawn qed parti

438
00:17:47,100 --> 00:17:48,770
kunċettwali, part hands-on.

439
00:17:48,770 --> 00:17:52,190
Aħna ser speċifikament tuża l-sezzjoni ta 'mistoqsijiet, parti

440
00:17:52,190 --> 00:17:54,110
tal-ġimgħa problema sett, jimxu permezz xi wħud mill-

441
00:17:54,110 --> 00:17:55,820
materjal kunċettwali minn lecture.

442
00:17:55,820 --> 00:17:57,480
U li kollox fis-sett problema attwali.

443
00:17:57,480 --> 00:18:00,010
U aħna ser ukoll adsa fis xi attivitajiet hands-on, xi kultant

444
00:18:00,010 --> 00:18:02,190
li se jkunu meħtieġa biex jiġu sottomessi, xi kultant ta '

445
00:18:02,190 --> 00:18:02,830
li mhux se.

446
00:18:02,830 --> 00:18:04,630
Per eżempju, din il-ġimgħa 1, dawn qed maħsuba biss bħala

447
00:18:04,630 --> 00:18:05,780
warm-up eżerċizzju.

448
00:18:05,780 --> 00:18:07,800
U inti ser issib li dawn il-problemi huma verament dan.

449
00:18:07,800 --> 00:18:10,220
Huma qed maħsuba li tkun pjuttost żgħar, iżda mhux neċessarjament

450
00:18:10,220 --> 00:18:13,100
programmi trivjali li tikteb, li mhumiex neċessarjament

451
00:18:13,100 --> 00:18:16,230
opportunitajiet eċċitanti u minnhom infushom, iżda huma tajbin għall-

452
00:18:16,230 --> 00:18:19,620
prattika ma sintassi, ma 'funzjonijiet ġodda, fil-kumdità ta'

453
00:18:19,620 --> 00:18:21,900
sezzjoni fejn inti għandek ftit ta 'klassi tiegħek tippreżenta mill-

454
00:18:21,900 --> 00:18:22,870
ukoll TF tiegħek.

455
00:18:22,870 --> 00:18:26,210
>> U dak li aħna ser nagħmlu matul iż-żmien huwa l-użu ta 'għodda msejħa CS50 Spazji,

456
00:18:26,210 --> 00:18:28,940
fejn minflok sempliċiment bl-użu Appliance CS50, inti ser

457
00:18:28,940 --> 00:18:32,450
minflok imorru għal paġna web browser, fejn inti ser ikunu jistgħu

458
00:18:32,450 --> 00:18:35,610
biex jikteb il-kodiċi fil-tieqa browser matul is-sezzjoni.

459
00:18:35,610 --> 00:18:38,240
U mbagħad jekk inti opt in, sħabi tagħlim tiegħek jista 'mbagħad juru

460
00:18:38,240 --> 00:18:40,980
kwalunkwe huwa int ittajpjar fuq l-iskrin tiegħek fil-browser tiegħek

461
00:18:40,980 --> 00:18:43,930
tieqa up fuq quddiem tal-klassi, sew jekk b'mod anonimu jew

462
00:18:43,930 --> 00:18:47,250
pubblikament, sabiex hu jew hi jistgħu mbagħad jimxu permezz ta 'l

463
00:18:47,250 --> 00:18:50,080
klassi tiegħek dak li għamilt tajjeb, dak li inti ma tagħmel tajjeb.

464
00:18:50,080 --> 00:18:52,750
U għal darb'oħra, mistrieħ assigurat dan kollu jista 'jiġi nicely għamla anonima.

465
00:18:52,750 --> 00:18:54,410
Iżda dan ser ikun opportunità sbieħ għal ħafna aktar

466
00:18:54,410 --> 00:18:56,810
interattività minn xi ħaġa bħal lecture tippermetti.

467
00:18:56,810 --> 00:18:58,910
>> Fil-frattemp, aħna ser ikollhom dawn l-affarijiet imsejħa super

468
00:18:58,910 --> 00:19:01,610
sezzjonijiet, li huma fakultattivi, imma huma miftuħa għal kulħadd fl-

469
00:19:01,610 --> 00:19:04,030
il-klassi, sabiex inti tista 'tagħmel dan aktar kollettivament għal

470
00:19:04,030 --> 00:19:05,190
problema sett wieħed.

471
00:19:05,190 --> 00:19:06,010
Hawn l-iskeda.

472
00:19:06,010 --> 00:19:08,870
Dan huwa wkoll stazzjonati fuq il-homepage fuq cs50.net.

473
00:19:08,870 --> 00:19:10,850
Avviż li se jkun hemm xi Hacker speċifiku

474
00:19:10,850 --> 00:19:12,430
wara nofsinhar għada waħda.

475
00:19:12,430 --> 00:19:15,460
U aħna se jiffilmjaw waħda llum u waħda għada u post dawk

476
00:19:15,460 --> 00:19:16,720
online fi żmien 24 siegħa.

477
00:19:16,720 --> 00:19:19,370
Mela jekk inti ma tistax tagħmel xi wieħed minn dawn iż-żminijiet, biex ma tinkwetax.

478
00:19:19,370 --> 00:19:22,720
U għal darb'oħra, l-iskeda hija online issa fil cs50.net.

479
00:19:22,720 --> 00:19:25,350
>> F'termini ta 'sezzjonali innifsu, għandek gotten xi

480
00:19:25,350 --> 00:19:28,520
email struzzjonijiet biex tmur għall-homepage tal-kors li ssib

481
00:19:28,520 --> 00:19:29,610
out sezzjoni tiegħek.

482
00:19:29,610 --> 00:19:32,890
Jekk il-ħajja nbidlet u li għandek bżonn għall-bidla taqsima tiegħek,

483
00:19:32,890 --> 00:19:33,560
mhux problema.

484
00:19:33,560 --> 00:19:37,900
Mur lura għal dak URL istess, cs50.net/section, singular,

485
00:19:37,900 --> 00:19:40,090
u tkun taf timla l-formola simili sabiex inti tista '

486
00:19:40,090 --> 00:19:41,260
imbagħad tagħtina preferenzi tiegħek.

487
00:19:41,260 --> 00:19:43,360
U aħna se ssegwi mill-aħħar ġimgħa dwar dak li nistgħu

488
00:19:43,360 --> 00:19:44,240
jakkomodaw.

489
00:19:44,240 --> 00:19:49,530
Last week, ifakkar li aħna pproponiet li jużaw CS50 Iddiskuti,

490
00:19:49,530 --> 00:19:51,370
il-kors tal-diskussjoni għodda, fil lecture.

491
00:19:51,370 --> 00:19:53,680
Allura kellna 40 mistoqsijiet li kienu mitluba u

492
00:19:53,680 --> 00:19:54,720
wieġeb matul lecture.

493
00:19:54,720 --> 00:19:56,280
Għalhekk deher li jaħdmu tajjeb, hekk aħna ser tkompli

494
00:19:56,280 --> 00:19:57,180
tipprova tagħmel dan.

495
00:19:57,180 --> 00:19:59,600
Jekk, matul taħdita, inti mhux biss jħossuhom komdi kuxjenza

496
00:19:59,600 --> 00:20:00,780
naħa tiegħek, mhux problema.

497
00:20:00,780 --> 00:20:04,640
Mur cs50.net/discuss, post hemm, u wieħed tat-tagħlim tagħna

498
00:20:04,640 --> 00:20:07,270
fellows jew se twieġeb b'mod elettroniku jew jgħollu tagħhom

499
00:20:07,270 --> 00:20:10,620
idejn f'ismek anonimu li titlob, skont

500
00:20:10,620 --> 00:20:12,470
in-natura tal-kwistjoni.

501
00:20:12,470 --> 00:20:15,000
U f'termini ta 'feedback, ġeneralment psets se jkun

502
00:20:15,000 --> 00:20:16,760
lura fi żmien ġimgħa.

503
00:20:16,760 --> 00:20:19,080
Għaliex tieħu ftit filwaqt li għal sezzjonijiet biex jinkiseb

504
00:20:19,080 --> 00:20:22,430
ekwilibriju, l pset 1, 0 u 1, se jkun ftit

505
00:20:22,430 --> 00:20:24,130
ittardjata bħala affarijiet jissetilja.

506
00:20:24,130 --> 00:20:27,130
Iżda tissospendi sintonizzat għal dak fil-ġimgħat li ġejjin.

507
00:20:27,130 --> 00:20:29,750
>> Kull dritt, so let me jitqiegħdu fuq serja tiegħi

508
00:20:29,750 --> 00:20:31,040
vuċi għal ftit mument.

509
00:20:31,040 --> 00:20:32,690
Allura dan huwa attwalment klima interessanti li tkun

510
00:20:32,690 --> 00:20:35,210
jkollhom din id-diskussjoni, liema kollha ta 'l-affarijiet oħra

511
00:20:35,210 --> 00:20:37,310
għaddej fuq magħhom kampus relatati.

512
00:20:37,310 --> 00:20:40,220
Iżda CS50 ċertament kellha l-istorja tagħha ta 'din partikolari

513
00:20:40,220 --> 00:20:43,360
suġġett, safejn jidħlu kull sena, dan il-kors, għal ħafna

514
00:20:43,360 --> 00:20:46,910
snin, Ad-Bordijiet madwar 3% tal-klassi.

515
00:20:46,910 --> 00:20:51,620
Din is-sena l-aktar riċenti, 2011, CS50 Ad-mbarkat 35 istudenti.

516
00:20:51,620 --> 00:20:54,120
Din mhix, naħseb, minħabba nuqqas ta 'ċarezza.

517
00:20:54,120 --> 00:20:56,760
Jirrealizzaw li fil sillabu tal-kors, hemm paġna ta '

518
00:20:56,760 --> 00:20:59,020
dikjarazzjoni li tispjega fejn il-linji huma.

519
00:20:59,020 --> 00:21:01,350
Dik id-dikjarazzjoni istess hija ripetuta fuq kull waħda mill-

520
00:21:01,350 --> 00:21:03,070
problema settijiet fuq paġna waħda.

521
00:21:03,070 --> 00:21:05,760
>> So I jsemmi dan llum verament biss biex jagħmlu

522
00:21:05,760 --> 00:21:07,030
folks konxji ta 'dan.

523
00:21:07,030 --> 00:21:08,080
U aħna stajt ppruvaw affarijiet differenti.

524
00:21:08,080 --> 00:21:10,630
U dak li ħsibt aħna se nagħmlu llum huwa biss tieħu mument biex

525
00:21:10,630 --> 00:21:13,830
attwalment tħares lejn uħud mill-każijiet tal-passat li jkunu ġejjin up.

526
00:21:13,830 --> 00:21:16,160
Pjuttost milli żżomm dawn sigrieti ftit maħmuġa kif, fil-fatt

527
00:21:16,160 --> 00:21:19,170
tfakkar dak l-istudenti għamlu u kif għandna skoperti

528
00:21:19,170 --> 00:21:21,630
dan u verament dak il-motivazzjoni globali hija għal

529
00:21:21,630 --> 00:21:23,950
anki wara li dan konverżazzjoni.

530
00:21:23,950 --> 00:21:27,060
Allura ma 'dak imsemmi, il-linja essenzjalment hija din -

531
00:21:27,060 --> 00:21:29,200
Skond il-sillabu, int milqugħa, inti huma mħeġġa, biex

532
00:21:29,200 --> 00:21:30,210
tkellem mal-klassi.

533
00:21:30,210 --> 00:21:31,910
Dik hija l-iskop kollu ta 'wara dawn il-kollaborazzjoni

534
00:21:31,910 --> 00:21:34,470
uffiċċju siegħa Annenberg u nies inkoraġġanti għall-

535
00:21:34,470 --> 00:21:35,755
proġett finali biex jaħdmu flimkien.

536
00:21:35,755 --> 00:21:38,590
Iżda l-linja huwa mfassal meta niġu żmien li attwalment jiktbu

537
00:21:38,590 --> 00:21:39,790
soluzzjoni finali tiegħek.

538
00:21:39,790 --> 00:21:42,590
Taħdit bl-Ingliż, totalment multa, jitkellem fil-kodiċi psewdo,

539
00:21:42,590 --> 00:21:43,400
totalment multa.

540
00:21:43,400 --> 00:21:46,340
Email classmate pset tiegħek, kiri lilhom ħarsa fuq

541
00:21:46,340 --> 00:21:48,610
l-iskrin kif l-idejn tkompli ittajpjar,

542
00:21:48,610 --> 00:21:50,110
fuq il-linja kif ukoll.

543
00:21:50,110 --> 00:21:52,250
Do inħarsu lejn il-sillabu għal-linji partikolari.

544
00:21:52,250 --> 00:21:55,850
>> Iżda biss li jagħti stampa ta 'kif dan huwa sfortunatament

545
00:21:55,850 --> 00:21:58,370
realtà, tirrealizza li hemm websajts hemmhekk li

546
00:21:58,370 --> 00:22:01,490
jkollhom soluzzjonijiet minn din il-klassi u l-klassijiet ħafna oħrajn.

547
00:22:01,490 --> 00:22:04,940
Il-fatt li inti jew xi 3% ta 'inti taf li dan jeżisti

548
00:22:04,940 --> 00:22:07,240
tfisser li aħna nafu li dan jeżisti.

549
00:22:07,240 --> 00:22:09,340
Il-fatt li hemm websajts bħal dan fejn inti

550
00:22:09,340 --> 00:22:11,540
jistgħu jħallsu xi ħadd li fil-fatt jagħmlu settijiet problema tiegħek - dan kien

551
00:22:11,540 --> 00:22:13,450
każ attwali li ħarāu aħħar sena.

552
00:22:13,450 --> 00:22:15,790
Din hija website imsejjaħ odesk.com.

553
00:22:15,790 --> 00:22:20,090
U Tim kien l-isem tal-persuna hawn li kien kollokament fuq

554
00:22:20,090 --> 00:22:24,580
din il-websajt u talbu xi ħadd li jagħmel pset tiegħu 7 fil

555
00:22:24,580 --> 00:22:25,570
din partikolari il-każ.

556
00:22:25,570 --> 00:22:28,350
Ukoll, odesk.com huwa ħafna Google-kapaċi, u aħna wisq huma

557
00:22:28,350 --> 00:22:30,310
tajjeb ħafna fil Googling.

558
00:22:30,310 --> 00:22:32,360
Hawnhekk, ukoll, hemm siti - u dan wieħed pjuttost

559
00:22:32,360 --> 00:22:34,234
atroċi, franchement.

560
00:22:34,234 --> 00:22:38,050
[Daħk]

561
00:22:38,050 --> 00:22:39,610
DAVID J. Malan: Il-ħaġa umoristiċi dwar dan is-sit huwa jekk

562
00:22:39,610 --> 00:22:41,970
taqra l-paġna About, huma jitkellmu dwar korporattiva tagħhom

563
00:22:41,970 --> 00:22:44,390
servizz tal-klijent kultura u kemm hu tagħhom numru wieħed

564
00:22:44,390 --> 00:22:46,190
prijorità, biex tiżgura li assenjazzjonijiet tiegħek jiksbu

565
00:22:46,190 --> 00:22:47,890
kellu fil-ħin.

566
00:22:47,890 --> 00:22:50,580
>> Iżda fil-serjetà kollha, għal darb'oħra, il-fatt li dawn is-siti

567
00:22:50,580 --> 00:22:52,910
jeżistu, realizzata aħna, ukoll, huma Filwaqt li jirrikonoxxu

568
00:22:52,910 --> 00:22:53,730
dawn it-tipi ta 'siti.

569
00:22:53,730 --> 00:22:55,890
U biex jagħtuk sens ta 'dak li jagħmel din ġeneralment

570
00:22:55,890 --> 00:22:58,570
jieħu, aħna ġeneralment ma jkollhomx skandli kbar fejn in-nies

571
00:22:58,570 --> 00:23:01,080
qed jikkollaboraw fuq kwalunkwe tip ta 'skala kbira, iżda pjuttost

572
00:23:01,080 --> 00:23:04,540
huwa f'dawn il-mumenti tard bil-lejl ta 'dgħjufija, fejn għandek hekk

573
00:23:04,540 --> 00:23:07,550
ħafna x'isir, huwa 04:00, int eżawriti, u int

574
00:23:07,550 --> 00:23:09,770
taħseb li yourself, ukoll, let me biss tagħti ħarsa lejn tiegħi

575
00:23:09,770 --> 00:23:11,770
roommate jew kodiċi ħabib tiegħi jew simili.

576
00:23:11,770 --> 00:23:14,800
U l-manifestazzjonijiet ta 'dan sfortunatament jinvolvu Istudenti

577
00:23:14,800 --> 00:23:17,640
A ħaġa sottomissjoni bħal din u l-preżentazzjoni B Student

578
00:23:17,640 --> 00:23:20,370
xi ħaġa bħal din, li ċertament, fil-kompjuter

579
00:23:20,370 --> 00:23:23,830
klassi tax-xjenza, huwa tassew faċli għax-xjenzati tal-kompjuter

580
00:23:23,830 --> 00:23:25,690
għall-individwazzjoni ma 'software.

581
00:23:25,690 --> 00:23:28,410
Dan huwa pass ieħor paradigma komuni, fejn inti ħadthom tip ta '

582
00:23:28,410 --> 00:23:31,010
ilha taħdem flimkien ta 'xi ħadd, forsi jitkellem fil

583
00:23:31,010 --> 00:23:32,360
Ingliż, biss multa, pseudocode.

584
00:23:32,360 --> 00:23:35,080
Iżda mbagħad niġu żmien li attwalment jissottomettu, u l-psets

585
00:23:35,080 --> 00:23:37,910
biss tikseb skambjata permezz ta 'email jew Dropbox jew affarijiet simili.

586
00:23:37,910 --> 00:23:41,120
Iżda f'attentat biex jagħmilha inqas evidenti li din hija

587
00:23:41,120 --> 00:23:44,830
dak li ġara, allura dan hu dak li sottomessi.

588
00:23:44,830 --> 00:23:47,880
Dan, ukoll, ma vjaġġ sal sew bil-miktub biċċiet ta '

589
00:23:47,880 --> 00:23:50,360
softwer bħal għandna attwalment skoperti

590
00:23:50,360 --> 00:23:51,280
dawn it-tipi ta 'affarijiet.

591
00:23:51,280 --> 00:23:53,760
U fil-fatt dak li nagħmlu huwa softwer run li jqabbel kollha ta '

592
00:23:53,760 --> 00:23:55,540
sottomissjonijiet din is-sena kontra kollha ta 'l-aħħar sena

593
00:23:55,540 --> 00:23:57,380
sottomissjonijiet, kontra dak kollu li sibna fuq il-

594
00:23:57,380 --> 00:24:00,060
Internet, kontra kull website impjieg hemmhekk.

595
00:24:00,060 --> 00:24:01,710
Huwa kollha ħafna awtomatizzata.

596
00:24:01,710 --> 00:24:05,665
U hekk nagħmlu dan verament fil-ġustizzja kbira għall-97% li

597
00:24:05,665 --> 00:24:07,760
huma verament jaħdmu ħmir tagħhom off f'dan u fl-ieħor

598
00:24:07,760 --> 00:24:11,530
klassijiet u tqegħid fil kollha ta 'dak l-isforz sabiex il-ħidma

599
00:24:11,530 --> 00:24:13,030
dawn kienu finalment iressqu huwa tagħhom stess.

600
00:24:13,030 --> 00:24:14,220
U jien tista 'tmur fuq għall-etajiet.

601
00:24:14,220 --> 00:24:16,030
>> Dawn huma biss ftit każijiet sena li għaddiet.

602
00:24:16,030 --> 00:24:19,350
A istudenti ftit sottomessa dawn il-fajls identiku għal pset 2,

603
00:24:19,350 --> 00:24:22,460
pset 3, pset 4, pset 5, pset 6, pset 9.

604
00:24:22,460 --> 00:24:26,360
F'dan il-każ, dan kien kwizz 0 u fl-aħħar sena, fejn tnejn

605
00:24:26,360 --> 00:24:29,570
istudenti sottomessa identiku din is-sentenza fost ħafna

606
00:24:29,570 --> 00:24:32,210
oħrajn, "It-talba tat-tip -" dot, dot, dot.

607
00:24:32,210 --> 00:24:34,530
Allura anke fi klassi ta '600 ma aħna jiskopru dan

608
00:24:34,530 --> 00:24:36,310
fuq sottomessa kwizzijiet.

609
00:24:36,310 --> 00:24:39,080
Allura fil-qosor, dan - franchement, I hate wara dan it-tip ta '

610
00:24:39,080 --> 00:24:41,300
konverżazzjoni - iżda dan huwa verament sforz deliberat

611
00:24:41,300 --> 00:24:43,540
din is-sena biex tipprova nbaxxu dak in-numru.

612
00:24:43,540 --> 00:24:45,650
Minħabba li anke jekk aħna ngħidu dawn it-tipi ta 'affarijiet kull

613
00:24:45,650 --> 00:24:48,100
sena, naħseb li l-realtà ta 'wara dwelled fuqha għal ftit

614
00:24:48,100 --> 00:24:50,800
aktar sekonda mis-soltu u fil-fatt biss li fakkret

615
00:24:50,800 --> 00:24:53,600
li dak li jista 'jidher, eh, mhux tali big deal, mill-inqas

616
00:24:53,600 --> 00:24:56,390
naħseb lura għal dan il-mument partikolari, kemm l-ekwità li

617
00:24:56,390 --> 00:25:00,100
yourself u biex klassi tiegħek hawn.

618
00:25:00,100 --> 00:25:02,480
Mela jekk inti qatt xi mistoqsijiet dwar fejn il-linja

619
00:25:02,480 --> 00:25:04,290
huwa, jekk jogħġbok biss jilħqu lili personalment.

620
00:25:04,290 --> 00:25:07,190
Iżda l-tweġiba hija dejjem, kompletament enfasizzat fil-

621
00:25:07,190 --> 00:25:09,090
aħħar minuta, flus kontanti fil-jum tard.

622
00:25:09,090 --> 00:25:11,080
Jew jekk huwa kwistjoni ta 'ma jkollhomx xi jiem tard,

623
00:25:11,080 --> 00:25:12,900
onestament, email me personalment.

624
00:25:12,900 --> 00:25:14,110
Aħna ser figura xi ħaġa barra.

625
00:25:14,110 --> 00:25:17,480
Jekk jogħġbok ma jitqiegħdu ħin tiegħek hawn fil-Harvard f'riskju.

626
00:25:17,480 --> 00:25:18,570
>> Issa, ħsibt għandna jiħfief il-burdata, so I

627
00:25:18,570 --> 00:25:20,264
inkluż dan bħala l-slide li jmiss.

628
00:25:20,264 --> 00:25:22,770
[Daħk]

629
00:25:22,770 --> 00:25:23,630
DAVID J. Malan: Dan il-websajt kien kbir.

630
00:25:23,630 --> 00:25:24,820
I attwalment ltqajna ftit distratt.

631
00:25:24,820 --> 00:25:26,330
Hemm dan wieħed.

632
00:25:26,330 --> 00:25:29,590
U mbagħad dan wieħed kien aqwa.

633
00:25:29,590 --> 00:25:35,190
Okay, hekk naħseb ta 'dak kitten tard bil-lejl meta jagħmlu

634
00:25:35,190 --> 00:25:36,040
dawk id-deċiżjonijiet.

635
00:25:36,040 --> 00:25:40,110
Kull dritt, Jittieħed hekk lura għall-gost aktar u inqas serji, bħal

636
00:25:40,110 --> 00:25:40,780
kundizzjonijiet.

637
00:25:40,780 --> 00:25:43,900
>> Kull dritt, hekk aħna tkellimna fil-qosor dwar dawn.

638
00:25:43,900 --> 00:25:46,080
Din hija xi ħaġa li probabbilment pjuttost familjari minn

639
00:25:46,080 --> 00:25:47,260
-dinja ta 'Scratch.

640
00:25:47,260 --> 00:25:49,860
U fid-dinja tal Scratch, aħna għandna din il-ħtieġa kultant li

641
00:25:49,860 --> 00:25:51,110
jmorru jagħmlu frieket fit-triq.

642
00:25:51,110 --> 00:25:54,840
Jew tagħmel dan jew dak jew dan ħaġa oħra hawn.

643
00:25:54,840 --> 00:25:58,990
U meta rridu nagħmlu dan, aħna jistgħu jużaw, fis-C issa, dan jekk

644
00:25:58,990 --> 00:26:00,860
inkella jinbena.

645
00:26:00,860 --> 00:26:06,420
U allura hawnhekk għandna espressjonijiet Boolean.

646
00:26:06,420 --> 00:26:09,260
Per eżempju, l-espressjonijiet Boolean hawn, nistgħu JEW

647
00:26:09,260 --> 00:26:12,260
flimkien, fis-sens li aħna għandna din il-kundizzjoni JEW

648
00:26:12,260 --> 00:26:13,200
din il-kundizzjoni.

649
00:26:13,200 --> 00:26:15,100
Nistgħu U flimkien, fis-sens li rridu

650
00:26:15,100 --> 00:26:17,710
tivverifika din il-kundizzjoni U din il-kundizzjoni.

651
00:26:17,710 --> 00:26:22,440
U hawn aħna għandna dikjarazzjoni swiċċ issa, li mhuwiex tant

652
00:26:22,440 --> 00:26:26,040
simili sintattiku għal dawk tipi ta 'kundizzjonijiet, iżda

653
00:26:26,040 --> 00:26:30,160
jippermetti li jagħmlu l-ekwivalenti ta 'jekk, inkella jekk, inkella jekk, inkella

654
00:26:30,160 --> 00:26:34,990
jekk, u simili billi sempliċiment enumerazzjoni minnhom każ b'każ

655
00:26:34,990 --> 00:26:36,670
billi każ b'każ.

656
00:26:36,670 --> 00:26:38,370
Allura aħna raw dawk aħħar darba.

657
00:26:38,370 --> 00:26:40,430
U allura bdejna tintmiss affarijiet simili loops.

658
00:26:40,430 --> 00:26:42,070
Rajna wieħed minn dawn biss mument ilu.

659
00:26:42,070 --> 00:26:44,180
Iżda hemm dawn constructs looping oħra.

660
00:26:44,180 --> 00:26:46,370
>> Per eżempju, dan wieħed hawn.

661
00:26:46,370 --> 00:26:50,140
Għalhekk, filwaqt li (kundizzjoni), jagħmlu dan ħaġa ġdid u għal darb'oħra.

662
00:26:50,140 --> 00:26:53,070
Allura fundamentalment, dak li jidher li jkun differenti bejn din

663
00:26:53,070 --> 00:26:55,760
għal linja u dan loop filwaqt hawn?

664
00:27:00,810 --> 00:27:05,045
Dan għal loop u dan loop waqt.

665
00:27:05,045 --> 00:27:07,840
Yeah?

666
00:27:07,840 --> 00:27:08,800
X'hemm li?

667
00:27:08,800 --> 00:27:10,050
UDJENZA: [inaudible].

668
00:27:14,632 --> 00:27:15,120
DAVID J. Malan: Tajba.

669
00:27:15,120 --> 00:27:17,130
Allura billi fil-linja għall-kundizzjoni, hemm b'mod ċar

670
00:27:17,130 --> 00:27:17,940
aktar sintassi.

671
00:27:17,940 --> 00:27:20,560
Hemm din inizjalizzazzjoni, hemm dan l-aġġornament.

672
00:27:20,560 --> 00:27:23,820
Fi loop waqt, hemm biss din il-kundizzjoni.

673
00:27:23,820 --> 00:27:26,630
Għalhekk jidher li huwa ftit tqassar kontra l-għar

674
00:27:26,630 --> 00:27:28,770
loop, li jfisser li jekk irridu li jkollna varjabbli u rridu

675
00:27:28,770 --> 00:27:30,800
li jkollhom incrementation, għandna attwalment ikollhom

676
00:27:30,800 --> 00:27:32,500
tagħmel dan ħaġa nfusna.

677
00:27:32,500 --> 00:27:34,420
>> So let me go l quddiem u tiftaħ gedit.

678
00:27:34,420 --> 00:27:36,320
Let me jisswiċċja għall-appliance.

679
00:27:36,320 --> 00:27:38,110
U ejja biss tagħmel eżempju ftit malajr li

680
00:27:38,110 --> 00:27:40,550
tiddistingwi wieħed minn dawn mill-ieħor.

681
00:27:40,550 --> 00:27:42,490
U fil-dahar tal-moħħ tiegħi hawnhekk, I għandha tgħid ħaġa waħda.

682
00:27:42,490 --> 00:27:44,120
Jiena speċifikament imsemmija l-isem Tim.

683
00:27:44,120 --> 00:27:47,740
Tim kien effettivament xi ħadd li student ppruvaw isibu jagħmlu

684
00:27:47,740 --> 00:27:48,680
huiswerk tagħhom għalihom.

685
00:27:48,680 --> 00:27:51,280
Kellna l-ebda Tim f'dik is-sezzjoni partikolari.

686
00:27:51,280 --> 00:27:53,690
Allura realizzata, lest I żvelata student, ma kienx student.

687
00:27:53,690 --> 00:27:55,720
Kienet persuna każwali fuq l-Internet nagħmlu l-affarijiet

688
00:27:55,720 --> 00:27:57,180
mill-aħħar sena prokura.

689
00:27:57,180 --> 00:27:58,670
Allura insibu li, wisq.

690
00:27:58,670 --> 00:28:00,630
Allura f'dan il-każ hawnhekk, let me imorru quddiem u

691
00:28:00,630 --> 00:28:02,810
jiftħu fajl ġdid.

692
00:28:02,810 --> 00:28:04,800
File, New.

693
00:28:04,800 --> 00:28:06,050
Dan jagħti me a tab hawn.

694
00:28:06,050 --> 00:28:09,940
Let me imorru quddiem u ħlief bħala loop.c.

695
00:28:09,940 --> 00:28:11,810
Let me go u kklikkja Save.

696
00:28:11,810 --> 00:28:15,340
U mbagħad stabbiliti hawn, ejja imorru quddiem u tibda bil-miktub

697
00:28:15,340 --> 00:28:16,605
# Jinkludu <stdio.h>.

698
00:28:19,116 --> 00:28:20,520
Let me zoom pulzieri

699
00:28:20,520 --> 00:28:23,410
Issa aħna ser nagħmlu prinċipali int (vojt).

700
00:28:23,410 --> 00:28:30,020
Issa let me go quddiem u tagħmel għal (i int = 0; i <

701
00:28:30,020 --> 00:28:33,480
oh, 10; i + +).

702
00:28:33,480 --> 00:28:36,620
U issa jien se jimxi 'l quddiem u jagħmlu jistampaw l-istilla li jien

703
00:28:36,620 --> 00:28:37,890
għamlet qabel.

704
00:28:37,890 --> 00:28:39,390
U mbagħad fl-aħħar ta 'dan il-programm, aħna qed biss jmorru

705
00:28:39,390 --> 00:28:41,130
stampar ta 'linja ġdida, biss hekk li fil-pront tiegħi

706
00:28:41,130 --> 00:28:42,470
ma tfittex kollha messy.

707
00:28:42,470 --> 00:28:45,170
ritorn 0.

708
00:28:45,170 --> 00:28:47,610
Jidhru sintattikament korrett?

709
00:28:47,610 --> 00:28:48,040
S'issa.

710
00:28:48,040 --> 00:28:48,560
Mela ejja ara.

711
00:28:48,560 --> 00:28:51,290
>> So let me zoom out, mur fil tieqa terminal tiegħi.

712
00:28:51,290 --> 00:28:54,570
U let me imorru quddiem u run loop, minħabba I sejjaħ din

713
00:28:54,570 --> 00:28:55,690
loop.c. ħaġa

714
00:28:55,690 --> 00:28:56,780
Sabiex tagħmel loop.

715
00:28:56,780 --> 00:28:57,840
Jidher li jikkompilaw OK.

716
00:28:57,840 --> 00:29:00,210
Let me run loop, u issa Ikteb.

717
00:29:00,210 --> 00:29:01,820
U jidher li jkollhom stampat 10 istilel.

718
00:29:01,820 --> 00:29:03,780
Mela ejja biss jikkonvertu dan ma 'linja waqt u ara dak

719
00:29:03,780 --> 00:29:05,220
tipi ta 'kwistjonijiet aħna vjaġġ fuq.

720
00:29:05,220 --> 00:29:11,290
Allura minflok dan, let me go fil hawn u jgħidu filwaqt i hija

721
00:29:11,290 --> 00:29:12,760
inqas minn 10 -

722
00:29:12,760 --> 00:29:14,910
let me jeħles mill-linja ta '.

723
00:29:14,910 --> 00:29:17,170
OK, hekk aħna jkollhom ftit problemi diġà.

724
00:29:17,170 --> 00:29:21,110
Allura l-kundizzjoni huwa l-istess, imma jien ovvjament nieqsa l-

725
00:29:21,110 --> 00:29:21,680
inizjalizzazzjoni.

726
00:29:21,680 --> 00:29:23,840
I am nieqsa l-incrementation.

727
00:29:23,840 --> 00:29:28,020
Allura dak li għandu l-kumpilatur probabbli tell me meta nipprova li

728
00:29:28,020 --> 00:29:29,170
jiġbor dan il-programm?

729
00:29:29,170 --> 00:29:29,666
Yeah?

730
00:29:29,666 --> 00:29:31,154
UDJENZA: [inaudible].

731
00:29:31,154 --> 00:29:31,650
>> DAVID J. Malan: Tajba.

732
00:29:31,650 --> 00:29:34,180
Allura huwa għaddej biex ngħid xi ħaġa simili mhux dikjarat - f'dan il-

733
00:29:34,180 --> 00:29:35,280
każ, varjabbli i.

734
00:29:35,280 --> 00:29:37,980
U fil-fatt, l-użu ta 'identifikatur mhux iddikjarat i.

735
00:29:37,980 --> 00:29:40,960
U hekk dan huwa b'kuntrast ma 'lingwi bħal PHP u

736
00:29:40,960 --> 00:29:43,120
Python u Ruby, li magħhom xi wħud minnkom jista 'jkun familjari,

737
00:29:43,120 --> 00:29:44,820
fejn inti tista 'biss tip ta' start-użu varjabbli

738
00:29:44,820 --> 00:29:47,420
Willy-nilly u ma għandekx għalfejn tinkwieta dwar tiddikjarahom

739
00:29:47,420 --> 00:29:48,560
espliċitament dejjem.

740
00:29:48,560 --> 00:29:51,770
Fil Ċ u fil-lingwi bħal Java u C + +, inti għandek tkun

741
00:29:51,770 --> 00:29:53,020
super espliċitu.

742
00:29:53,020 --> 00:29:55,760
U jekk inti tixtieq varjabbli imsejjaħ i, inti għandek tgħidli

743
00:29:55,760 --> 00:29:57,360
liema tip ta 'varjabbli huwa.

744
00:29:57,360 --> 00:29:59,360
Allura aħna qed tmur biex ikollhom biex jiffissaw dan kif ġej.

745
00:29:59,360 --> 00:30:05,510
Jien ser ikollhom imorru up hawn u t-tip i int, għalhekk,

746
00:30:05,510 --> 00:30:07,860
I jkunu ddikjaraw varjabbli imsejjaħ i.

747
00:30:07,860 --> 00:30:09,180
Issa, stajt skipped pass wieħed.

748
00:30:09,180 --> 00:30:11,340
Stajt ovvjament mhux initialized dan, imma ejja ara jekk dak in

749
00:30:11,340 --> 00:30:13,650
inqas waqfa clang jagħmel tilmenta.

750
00:30:13,650 --> 00:30:15,770
So let me remake dan il-programm.

751
00:30:15,770 --> 00:30:16,770
>> Kull dritt, issa huwa biss tilmenta

752
00:30:16,770 --> 00:30:17,870
għal raġuni differenti.

753
00:30:17,870 --> 00:30:21,130
"Varjabbli" i "hija uninitialized meta jintuża hawnhekk." Kull dritt, hekk

754
00:30:21,130 --> 00:30:22,340
li pjuttost espliċita.

755
00:30:22,340 --> 00:30:25,510
Initialized ifisser biss li dan ikun iffissat ugwali għal valur.

756
00:30:25,510 --> 00:30:30,820
U konna ma għamlux dan, so let me jippruvaw ikun egwali għal 0.

757
00:30:30,820 --> 00:30:35,030
Issa ejja tipprova dan mill-ġdid u jerġa 'jsir clang.

758
00:30:35,030 --> 00:30:36,140
Miġbura dan iż-żmien.

759
00:30:36,140 --> 00:30:37,210
U jien ser run.

760
00:30:37,210 --> 00:30:43,120
Iżda big loop infinita qodma, għaliex jien ghamilt l-

761
00:30:43,120 --> 00:30:45,530
inizjalizzazzjoni, jien ghamilt il-kundizzjoni, imma stajt qatt ma jsir

762
00:30:45,530 --> 00:30:47,030
kwalunkwe tip ta 'incrementation.

763
00:30:47,030 --> 00:30:48,780
Allura kif nista 'nagħmel l-incrementation?

764
00:30:48,780 --> 00:30:51,170
Ukoll, fil-linja waqt, huwa jħoss simili jien ser ikollhom

765
00:30:51,170 --> 00:30:54,180
biex tagħmel dan ġewwa tal-linja, għaliex ħafna bħall-ewwel

766
00:30:54,180 --> 00:30:56,570
Eżempji ġimgħa ta 'kif isir constructs looping, bħal ma

767
00:30:56,570 --> 00:30:59,040
l-kalzetti u mal-awto-għadd, kellna biex jagħmlu

768
00:30:59,040 --> 00:31:01,550
xi ħaġa fl-aħħar nett, nixtieq mur lura għall-linja li jmiss.

769
00:31:01,550 --> 00:31:05,040
X'jigri jekk imorru quddiem u tagħmel dan i + + hawn?

770
00:31:05,040 --> 00:31:06,030
Ejja ma anki jiġbor dan.

771
00:31:06,030 --> 00:31:06,890
Qabda me diġà.

772
00:31:06,890 --> 00:31:09,704
X'hemm ħażin hawn?

773
00:31:09,704 --> 00:31:10,690
UDJENZA: [inaudible].

774
00:31:10,690 --> 00:31:11,770
>> DAVID J. Malan: Allura huwa definittivament mhux int.

775
00:31:11,770 --> 00:31:13,080
Huwa i.

776
00:31:13,080 --> 00:31:15,110
U l-braces kaboċċi, bħal qabel,

777
00:31:15,110 --> 00:31:16,800
indentazzjoni mhuwiex biżżejjed.

778
00:31:16,800 --> 00:31:18,410
Allura issa għandi dan jinbena.

779
00:31:18,410 --> 00:31:21,780
Għalhekk, filwaqt li i huwa inqas minn 10, stampar ta 'stilla,

780
00:31:21,780 --> 00:31:23,220
imbagħad inkrement i.

781
00:31:23,220 --> 00:31:25,680
U l-mod waqt xogħlijiet loop huwa li hekk kif inti laqat il-

782
00:31:25,680 --> 00:31:29,630
qiegħ tal-linja, li f'dan il-każ qisu linja 10,

783
00:31:29,630 --> 00:31:32,880
li għaddej biex tmur lura għal linja 6, f'liema punt l-

784
00:31:32,880 --> 00:31:34,400
kundizzjoni ser jerġgħu jiġu verifikati.

785
00:31:34,400 --> 00:31:37,500
U jekk i għadu inqas minn 10, aħna ser tagħmel linji 8 u

786
00:31:37,500 --> 00:31:41,250
allura 9, allura aħna ser hit 10, u jmorru lura sa 6, għal darb'oħra u

787
00:31:41,250 --> 00:31:45,580
ġdid u għal darb'oħra u għal darb'oħra, sakemm i huwa inqas minn 10.

788
00:31:45,580 --> 00:31:47,860
Mela ejja jerġa 'jsir jagħmlu hawn.

789
00:31:47,860 --> 00:31:48,940
>> Okay, aħna ve miġbura okay.

790
00:31:48,940 --> 00:31:50,300
Let me-ripetizzjoni loop.

791
00:31:50,300 --> 00:31:52,620
U issa fil-fatt jidher li qed jaħdem.

792
00:31:52,620 --> 00:31:55,100
Allura pluses u minuses hawn?

793
00:31:55,100 --> 00:31:58,910
Ukoll, s'issa hemm attwalment mhux kollha, ta 'PLO -

794
00:31:58,910 --> 00:31:59,420
hekk ħelu.

795
00:31:59,420 --> 00:32:01,870
Kull dritt, li kienet - ah, li kien inċident.

796
00:32:01,870 --> 00:32:05,200
Kull dritt, hekk ejja mmorru lura għall-għall-loop.

797
00:32:05,200 --> 00:32:07,530
Allura għal linji huma sbieħ għaliex qed super espliċitu.

798
00:32:07,530 --> 00:32:09,720
U anki jekk dawn qed ftit clunky li tikteb, huwa

799
00:32:09,720 --> 00:32:11,500
qawwija ħafna u li jippermettilek li tagħmel

800
00:32:11,500 --> 00:32:12,980
affarijiet multipli fuq darba.

801
00:32:12,980 --> 00:32:16,240
Filwaqt loops ma jidhirx li jkollhom ammont kbir ta 'valur biss

802
00:32:16,240 --> 00:32:18,500
iżda, għaliex iħoss bħal aħna biss għandhom jagħmlu iktar xogħol.

803
00:32:18,500 --> 00:32:20,670
Għandna tpoġġi l-inizjalizzazzjoni up hawn, il-

804
00:32:20,670 --> 00:32:23,480
jaġġornaw stabbiliti hawn, u għandna niftakru li tagħmel dak kollu.

805
00:32:23,480 --> 00:32:26,260
Allura aħna ser tara fil-ħin li loops filwaqt attwalment jsellef

806
00:32:26,260 --> 00:32:29,380
ruħhom għall biss f'kuntesti differenti, data differenti

807
00:32:29,380 --> 00:32:33,900
strutturi bħal-listi u tabelli hash, affarijiet aħna ser tingħata biex

808
00:32:33,900 --> 00:32:34,970
nofs l-semestru.

809
00:32:34,970 --> 00:32:37,900
Iżda għal issa, jafu li hemm dan it-tip 3 magħruf bħala do-

810
00:32:37,900 --> 00:32:38,480
filwaqt loop.

811
00:32:38,480 --> 00:32:39,540
U Rajna din qosor.

812
00:32:39,540 --> 00:32:41,830
U dan jista 'jkun utli super mal pset 1.

813
00:32:41,830 --> 00:32:45,570
Kwalunkwe ħin li inti trid tagħmel xi ħaġa u mbagħad tiċċekkja jekk

814
00:32:45,570 --> 00:32:48,940
l-utent ikkooperaw, u jekk dawn ma, jagħmlu mill-ġdid, ta 'do-

815
00:32:48,940 --> 00:32:51,460
filwaqt loop jippresta ruħu għal dan it-tip ta 'loġika.

816
00:32:51,460 --> 00:32:55,640
Minħabba li l-ordni minn fuq għal isfel hawn jissuġġerixxi,

817
00:32:55,640 --> 00:32:57,750
do litteralment tfisser tagħmel dan.

818
00:32:57,750 --> 00:32:59,830
U tagħmel dan mill-ġdid u għal darb'oħra, dak li jista 'jkun?

819
00:32:59,830 --> 00:33:03,000
Forsi dan ifisser GetInt sejħa jew GetString u mbagħad

820
00:33:03,000 --> 00:33:05,830
iċċekkjar il-valur ta GetInt jew GetString u mbagħad yelling

821
00:33:05,830 --> 00:33:08,260
lejn l-utent jekk dawn ma jkunux ikkooperaw billi talbithom

822
00:33:08,260 --> 00:33:10,100
ġdid u għal darb'oħra u għal darb'oħra.

823
00:33:10,100 --> 00:33:11,730
Fejn inti tixtieq li tagħmel xi ħaġa darba,

824
00:33:11,730 --> 00:33:13,210
mbagħad tiċċekkja xi kundizzjoni.

825
00:33:13,210 --> 00:33:14,110
>> Mela ejja jippruvaw dan.

826
00:33:14,110 --> 00:33:17,130
Let me fil-fatt tbiddel dan issa ma 'linja do-waqt.

827
00:33:17,130 --> 00:33:18,830
U jien ser jimxi 'l quddiem u jagħmel dan li ġej.

828
00:33:18,830 --> 00:33:21,830
Allura tagħmel dan li ġej.

829
00:33:21,830 --> 00:33:26,870
Ejja nagħmlu i int = GetInt (); imma ejja 1 tell-utent

830
00:33:26,870 --> 00:33:27,410
x'għandek tagħmel.

831
00:33:27,410 --> 00:33:29,050
Allura ftit differenti dan iż-żmien.

832
00:33:29,050 --> 00:33:31,270
"Agħti me int".

833
00:33:31,270 --> 00:33:32,910
So I ser tuża printf għal dak.

834
00:33:32,910 --> 00:33:35,740
U issa jien se jinżlu hawn, u jien ser tagħmel dan

835
00:33:35,740 --> 00:33:41,520
filwaqt li i huwa, ejja ngħidu, akbar minn -

836
00:33:41,520 --> 00:33:47,540
ejja ara, i huwa, ejja ngħidu, inqas minn 0, jew i huwa

837
00:33:47,540 --> 00:33:48,730
akbar minn 10.

838
00:33:48,730 --> 00:33:51,810
Fi kliem ieħor, nixtieq numru minn 1 sa 9, biss

839
00:33:51,810 --> 00:33:52,720
arbitrarju.

840
00:33:52,720 --> 00:33:55,290
Allura jien jużaw espressjoni Boolean magħquda hawn biex

841
00:33:55,290 --> 00:33:59,930
kun żgur li i huwa inqas minn 0 jew akbar minn 10, li fih

842
00:33:59,930 --> 00:34:02,530
każ I se tagħmel dan loop hawn darb'oħra.

843
00:34:02,530 --> 00:34:04,400
Għalhekk għal darb'oħra, tagħmel dan -

844
00:34:04,400 --> 00:34:08,480
filwaqt li i huwa inqas minn 0 jew i huwa akbar minn 10.

845
00:34:08,480 --> 00:34:11,440
>> Allura issa ejja imorru quddiem u tagħmel dan darba aħna ghamilt dan.

846
00:34:11,440 --> 00:34:13,270
Ejja biss tagħmel verifika sanità malajr.

847
00:34:13,270 --> 00:34:18,929
printf ("Grazzi, i huwa% d", i).

848
00:34:18,929 --> 00:34:21,350
Allura dan il-programm sempliċi jitlob lill-utent għal int,

849
00:34:21,350 --> 00:34:24,000
jagħmel ċert li huwa fi ħdan xi firxa, 1 sa 9 inklużi,

850
00:34:24,000 --> 00:34:26,280
u mbagħad jirringrazzja lill-utent billi jitfakkru minnhom dak li biss

851
00:34:26,280 --> 00:34:27,940
ittajpjat fil, biss bħala verifika sanità ftit.

852
00:34:27,940 --> 00:34:30,659
Imma ejja ara jekk din taħdem kif maħsub.

853
00:34:30,659 --> 00:34:34,533
Let me go ras stabbiliti hawn u jerġa 'jsir jagħmlu loop.

854
00:34:34,533 --> 00:34:35,350
Hmm.

855
00:34:35,350 --> 00:34:38,600
"Użu ta 'identifikatur mhux iddikjarat" i "". Li stramba.

856
00:34:38,600 --> 00:34:41,509
Ħsibt aħna solvuta din.

857
00:34:45,489 --> 00:34:47,560
Sintomu istess iżda kodiċi differenti.

858
00:34:47,560 --> 00:34:47,899
Yeah?

859
00:34:47,899 --> 00:34:50,191
UDJENZA: [inaudible] ġewwa l-tnejn, għandna biex

860
00:34:50,191 --> 00:34:52,639
[Inaudible].

861
00:34:52,639 --> 00:34:53,260
>> DAVID J. Malan: Eżattament.

862
00:34:53,260 --> 00:34:55,989
Allura dan fil-fatt iwassalna għal suġġett magħruf bħala skop.

863
00:34:55,989 --> 00:34:59,350
Jirriżulta li C, għal darb'oħra, li verament jieħu inti litteralment.

864
00:34:59,350 --> 00:35:02,970
U jekk inti tagħmel xi ħaġa bħal din fejn inti tiddikjara int

865
00:35:02,970 --> 00:35:06,120
u mbagħad tassenja din xi valur, iżda inti tagħmel dan ġewwa ta '

866
00:35:06,120 --> 00:35:09,840
par ta 'ċineg kaboċċi, dak Ċ ma huwa jassumi li inti

867
00:35:09,840 --> 00:35:14,800
jridux biss dawk bits 32 magħrufa bħala i li jeżistu fi ħdan il-

868
00:35:14,800 --> 00:35:18,200
kuntest ta 'dawk ċineg kaboċċi, fil-kuntest ta' linji

869
00:35:18,200 --> 00:35:22,420
6 sa 9. Hekk i huwa ddikjarat, u din tiġi assenjata

870
00:35:22,420 --> 00:35:26,530
valur fil-linja 8, iżda hekk kif ikollok barra ta '

871
00:35:26,530 --> 00:35:30,270
Linja 9 hawn taħt il-Brace kaboċċi, i m'għadhiex

872
00:35:30,270 --> 00:35:31,910
ambitu, biex ngħidu hekk.

873
00:35:31,910 --> 00:35:35,030
S-C-O-P-E. Huwa m'għadux fil-kuntest dritt.

874
00:35:35,030 --> 00:35:37,940
Allura issa m'hemm l-ebda i, dan huwa kif għalkemm kellna lanqas

875
00:35:37,940 --> 00:35:38,770
iddikjarat fil-livelli kollha.

876
00:35:38,770 --> 00:35:41,520
>> Allura x'hemm jiffissaw imbagħad għal xi ħaġa bħal din, jekk il-

877
00:35:41,520 --> 00:35:44,300
raġuni hija li i tkun saret fil-ċingi kaboċċi, li

878
00:35:44,300 --> 00:35:45,120
hija apparentement ħażina?

879
00:35:45,120 --> 00:35:45,410
Hawnhekk?

880
00:35:45,410 --> 00:35:46,820
UDJENZA: [inaudible].

881
00:35:46,820 --> 00:35:47,150
DAVID J. Malan: Yeah.

882
00:35:47,150 --> 00:35:48,710
Allura nistgħu initialize barra.

883
00:35:48,710 --> 00:35:53,530
So let me go l quddiem u jħassru l-partijiet tad-dikjarazzjoni li permezz tagħha

884
00:35:53,530 --> 00:35:55,820
I jispeċifikaw it-tip, u let me do it up here.

885
00:35:55,820 --> 00:36:00,220
Allura fil-linja 5, issa jgħid "Agħti me int." Sejħa hija i.

886
00:36:00,220 --> 00:36:03,400
Avviż f'konformità 9, Ma rridx li tagħmel dan, minħabba I

887
00:36:03,400 --> 00:36:04,830
diġà għandhom l-bits 32.

888
00:36:04,830 --> 00:36:06,140
Ma rridx li titlob lill-kompjuter għal

889
00:36:06,140 --> 00:36:07,630
bits 32 differenti.

890
00:36:07,630 --> 00:36:09,850
Irrid li jużaw dawk l-istess 32 bits.

891
00:36:09,850 --> 00:36:13,190
U issa għaliex i huwa ddikjarat fil-linja 5, huwa għadu leġittimu

892
00:36:13,190 --> 00:36:16,550
li jużawh fil-linja 11 u linja 12.

893
00:36:16,550 --> 00:36:19,310
>> So let me jippruvaw recompile dan u ara

894
00:36:19,310 --> 00:36:20,490
waqfiet clang jekk yelling.

895
00:36:20,490 --> 00:36:22,380
jagħmlu loop.

896
00:36:22,380 --> 00:36:25,470
Allura issa huwa "dikjarazzjoni impliċita tal-funzjoni

897
00:36:25,470 --> 00:36:29,880
"GetInt" huwa invalidu C99. "X'inhi din?

898
00:36:29,880 --> 00:36:30,400
Yeah?

899
00:36:30,400 --> 00:36:32,330
UDJENZA: [inaudible].

900
00:36:32,330 --> 00:36:32,690
DAVID J. Malan: Yeah.

901
00:36:32,690 --> 00:36:35,520
Allura issa li jien attwalment jużaw GetInt, din mhix xi ħaġa

902
00:36:35,520 --> 00:36:38,190
li biss jiġi ma C. Dan ġej minn CS50.

903
00:36:38,190 --> 00:36:39,890
Għalhekk għandna bżonn dan hawn.

904
00:36:39,890 --> 00:36:41,450
U let me jmorru lura għall-isfel fil-pront

905
00:36:41,450 --> 00:36:43,500
hawn u jerġa 'jsir jagħmlu.

906
00:36:43,500 --> 00:36:44,160
Okay, finalment.

907
00:36:44,160 --> 00:36:46,270
Issa aħna stajt solvuti li u l-iżball oħra.

908
00:36:46,270 --> 00:36:48,930
Let me issa run loop u tara x'jiġri.

909
00:36:48,930 --> 00:36:51,740
"Agħti me int." I ser tagħtiha 11.

910
00:36:51,740 --> 00:36:53,100
I ser tagħtiha -1.

911
00:36:53,100 --> 00:36:54,470
I ser tagħtiha foo.

912
00:36:54,470 --> 00:36:56,080
I ser tagħtiha 5.

913
00:36:56,080 --> 00:36:57,450
U issa tabilħaqq taħdem.

914
00:36:57,450 --> 00:36:59,410
Iżda l-pront mibdula għal raġuni hawn.

915
00:36:59,410 --> 00:37:02,800
Għaliex ma jgħidu retry waħda minn dawn iż-żminijiet, iżda tagħti me

916
00:37:02,800 --> 00:37:03,920
int l-oħra tliet darbiet?

917
00:37:03,920 --> 00:37:05,500
Għaliex huwa li l-imġiba differenti?

918
00:37:05,500 --> 00:37:06,980
UDJENZA: Taw dan string.

919
00:37:06,980 --> 00:37:07,830
DAVID J. Malan: Jiddispjacini?

920
00:37:07,830 --> 00:37:08,570
UDJENZA: You tatha string.

921
00:37:08,570 --> 00:37:08,990
DAVID J. Malan: Yeah.

922
00:37:08,990 --> 00:37:11,450
Allura aħna tatha string f'dan tielet tentattiv,

923
00:37:11,450 --> 00:37:12,490
meta I ittajpjat foo.

924
00:37:12,490 --> 00:37:13,200
Foo hija sekwenza.

925
00:37:13,200 --> 00:37:14,340
Huwa ovvjament mhux int.

926
00:37:14,340 --> 00:37:17,500
U l-mod li CS50 implimentat GetInt hija li aħna

927
00:37:17,500 --> 00:37:20,330
ma tivverifika xi ħaġa jekk inqas minn 0 jew akbar minn 10

928
00:37:20,330 --> 00:37:22,260
għalik, għaliex kif nafu minn qabel liema tip ta '

929
00:37:22,260 --> 00:37:23,130
int trid?

930
00:37:23,130 --> 00:37:25,880
Iżda nistgħu minimament jiċċekkja għalik, ma l-utent għall-inqas

931
00:37:25,880 --> 00:37:26,730
tip integer?

932
00:37:26,730 --> 00:37:30,500
U jekk dawn ma, aħna Yell fil-utent billi jittajpja "retry" fuq

933
00:37:30,500 --> 00:37:31,440
l-iskrin.

934
00:37:31,440 --> 00:37:34,210
>> Allura issa għandna programm li l-looping. Okay.

935
00:37:34,210 --> 00:37:37,070
Issa, liema minn dawn huwa tip tal-konstruzzjoni aħjar?

936
00:37:37,070 --> 00:37:39,060
Allura dan huwa fejn affarijiet tibda tikseb messy ftit, l-

937
00:37:39,060 --> 00:37:42,360
fatt li inti għandek tiftakar li tiddikjara varjabbli up here

938
00:37:42,360 --> 00:37:44,630
jekk inti tixtieq li tagħmel użu minnha ġewwa ta 'xi

939
00:37:44,630 --> 00:37:46,460
braces kaboċċi u barra.

940
00:37:46,460 --> 00:37:48,490
Iżda anke jekk dan jistenna ftit cryptic fl-ewwel

941
00:37:48,490 --> 00:37:50,750
t'għajn, biss għal darb'oħra, ftakar il-loġika sempliċi.

942
00:37:50,750 --> 00:37:54,630
Sabiex jużaw xejn C, jekk huwa funzjoni jew

943
00:37:54,630 --> 00:37:57,680
huwa varjabbli, ikollok biex jinkludih jekk huwa funzjoni

944
00:37:57,680 --> 00:37:59,770
f'xi librerija, jew għandek bżonn li tiddikjaraha.

945
00:37:59,770 --> 00:38:02,405
Imma issa inti jeħtieġ li tkun konxja żejda tal-fatt li

946
00:38:02,405 --> 00:38:04,940
int tiddikjara lilha fl-ambitu dritt.

947
00:38:04,940 --> 00:38:08,150
Int mhux tqegħid wisq sewwa ġewwa tal parentesi.

948
00:38:08,150 --> 00:38:09,410
>> So let me attwalment roll lura.

949
00:38:09,410 --> 00:38:12,660
Jekk immorru lura għall tagħna per eżempju mill-ewwel, u mmur

950
00:38:12,660 --> 00:38:19,245
lura għall-għall int, int i = 0; i <10; i + +, u jien

951
00:38:19,245 --> 00:38:26,370
do stilla printf, bħal dan, u mbagħad paren qrib, u issa

952
00:38:26,370 --> 00:38:30,410
printf i huwa issa -

953
00:38:30,410 --> 00:38:33,500
skond l-istess loġika, x'se jiġri meta nipprova li

954
00:38:33,500 --> 00:38:35,500
jiġbor dan il-programm?

955
00:38:35,500 --> 00:38:36,790
UDJENZA: identifikatur Invalid.

956
00:38:36,790 --> 00:38:38,560
DAVID J. Malan: Allura huwa ieħor identifikatur invalidi,

957
00:38:38,560 --> 00:38:39,470
mhux iddikjarat identifikatur.

958
00:38:39,470 --> 00:38:41,810
Issa, ir-raġuni l-ftit differenti.

959
00:38:41,810 --> 00:38:44,370
Hemm ovvjament l-ebda ċineg kaboċċi hawn, iżda l-istess

960
00:38:44,370 --> 00:38:46,790
idea, l-istess storja ta 'ambitu japplika.

961
00:38:46,790 --> 00:38:50,340
Jekk inti ddikjarajt varjabbli bħal i ġewwa ta '

962
00:38:50,340 --> 00:38:53,960
għal loop, anki jekk int ma espliċitament bil-miktub l-kaboċċi

963
00:38:53,960 --> 00:38:56,980
ċingi, think minnhom mentalment bħala li għadhom jkunu hemm, li fih

964
00:38:56,980 --> 00:39:00,310
każ i huwa biss ġewwa validu tal-linja għall.

965
00:39:00,310 --> 00:39:03,080
M'huwiex validu ladarba inti tikseb l-linja li jmiss, li

966
00:39:03,080 --> 00:39:05,090
F'dan il-każ issa huwa 10.

967
00:39:05,090 --> 00:39:09,060
Allura biss ftit kwistjonijiet ta 'ambitu u simili.

968
00:39:09,060 --> 00:39:12,620
Kull dritt, xi mistoqsijiet?

969
00:39:12,620 --> 00:39:15,310
>> Kull dritt, hekk li dan huwa tip ta 'programm ftit trivjali,

970
00:39:15,310 --> 00:39:17,450
istampar biss stilla ftit.

971
00:39:17,450 --> 00:39:20,400
Imma ejja ara jekk inti tiftakar dan il-kanzunetta hawn.

972
00:39:20,400 --> 00:39:22,530
Din hija kanzunetta oerhört annoying-gidjien se nijet fuq

973
00:39:22,530 --> 00:39:23,550
il-bus iskola u simili.

974
00:39:23,550 --> 00:39:25,990
Imma x'hemm sbieħ dwar dan hija li dan ikollu din il ċikli,

975
00:39:25,990 --> 00:39:27,910
fejn huwa "99 fliexken tal-birra fuq il-ħajt,

976
00:39:27,910 --> 00:39:28,520
99 fliexken tal-birra.

977
00:39:28,520 --> 00:39:31,030
Ħu waħda isfel, tgħaddiha madwar, 98 fliexken tal-birra fuq il-

978
00:39:31,030 --> 00:39:34,330
ħajt. "U allura l-kanzunetta jirrepeti l-97, imbagħad 96, imbagħad

979
00:39:34,330 --> 00:39:38,040
95, imbagħad 94, it-triq kollha sa 0 jekk inti fil-fatt qbilna li

980
00:39:38,040 --> 00:39:38,920
ferm fuq ix-xarabank.

981
00:39:38,920 --> 00:39:41,960
Allura dan huwa programm sbieħ li sort ta timplimenta, għax tiegħi

982
00:39:41,960 --> 00:39:43,650
Alla, jekk inti tista 'biss jimplimentaw dan bi ftit

983
00:39:43,650 --> 00:39:46,660
linji ta 'kodiċi, inti tista' bżiq l-lirika kollu għal dan

984
00:39:46,660 --> 00:39:48,240
kanzunetta pjuttost malajr.

985
00:39:48,240 --> 00:39:50,420
Imma tul it-triq, nistgħu jibdew issa tease apparti xi

986
00:39:50,420 --> 00:39:52,460
ta 'dawn constructs looping bażiċi u issa wkoll

987
00:39:52,460 --> 00:39:55,830
jintroduċu funzjonijiet li aħna tikteb lilna nfusna, jirritornaw valuri

988
00:39:55,830 --> 00:39:57,020
li aħna jgħaddu madwar.

989
00:39:57,020 --> 00:39:58,910
Iżda l-ewwel, għaliex ma we jimxi 'l quddiem u tieħu tagħna ta' ħames minuti

990
00:39:58,910 --> 00:39:59,320
break hawn?

991
00:39:59,320 --> 00:40:01,480
U meta aħna nikseb lura, aħna se nijet dan kanzunetta.

992
00:40:05,680 --> 00:40:08,760
>> Kull dritt, hekk aħna lura.

993
00:40:08,760 --> 00:40:11,850
U meta ngħid aħna issa se nijet dan kanzunetta, I tfisser

994
00:40:11,850 --> 00:40:13,250
programmatically, mhux verbalment.

995
00:40:13,250 --> 00:40:19,370
Allura hawnhekk għandna beer1.c, li hija waħda implementazzjoni ta 'din

996
00:40:19,370 --> 00:40:20,580
kanzunetta partikolari.

997
00:40:20,580 --> 00:40:23,110
U biss li jkunu ċari, għal dawk familjari ma 'dak

998
00:40:23,110 --> 00:40:24,460
dan il-ħaġa tidher qiesha, let me imorru quddiem

999
00:40:24,460 --> 00:40:27,070
u jagħmlu beer1, Ikteb.

1000
00:40:27,070 --> 00:40:30,400
Issa let me run beer1, u dak li aħna ser tara - kemm fliexken

1001
00:40:30,400 --> 00:40:31,140
tal-birra se jkun hemm?

1002
00:40:31,140 --> 00:40:33,240
I ser tip 99, bħall-kanzunetta jgħid.

1003
00:40:33,240 --> 00:40:34,040
Ikteb.

1004
00:40:34,040 --> 00:40:35,650
U issa jekk aħna iscroll permezz -

1005
00:40:35,650 --> 00:40:38,280
Oops - jekk aħna iscroll kollha permezz ta 'dan, aħna ser tara li

1006
00:40:38,280 --> 00:40:41,350
dan tabilħaqq tkanta l-kanzunetta kollu.

1007
00:40:44,050 --> 00:40:44,540
Stenna minuta.

1008
00:40:44,540 --> 00:40:46,240
Bar scroll My l-ftit messed up.

1009
00:40:46,240 --> 00:40:47,940
Ejja jużaw il-tieqa akbar.

1010
00:40:47,940 --> 00:40:53,500
Allura beer1, 99, hemm we go.

1011
00:40:53,500 --> 00:40:56,420
Allura hawnhekk għandna l-kanzunetta kollu, kantata ħafna aktar mgħaġġla mill-

1012
00:40:56,420 --> 00:40:58,450
kompjuter milli seta 'kien mill us.

1013
00:40:58,450 --> 00:41:00,340
Allura avviż, għalkemm, in-natura ċiklika hawn.

1014
00:41:00,340 --> 00:41:03,380
Hija tgħid 99, imbagħad 99, imbagħad "tieħu waħda isfel, tgħaddiha

1015
00:41:03,380 --> 00:41:04,740
madwar, "imbagħad 98.

1016
00:41:04,740 --> 00:41:06,640
U issa jirrepeti ġdid u għal darb'oħra.

1017
00:41:06,640 --> 00:41:08,840
>> Allura dan huwa attwalment opportunità perfetta għal xi tip ta '

1018
00:41:08,840 --> 00:41:10,400
looping jinbena.

1019
00:41:10,400 --> 00:41:12,950
Avviż li jien tip ta 'qtugħ kantuniera hawn.

1020
00:41:12,950 --> 00:41:15,960
Avviż li jien qal "98 fliexken tal-birra fuq il-ħajt,

1021
00:41:15,960 --> 00:41:19,010
97 fliexken tal-birra fuq il-ħajt, "u li kien biss hekk

1022
00:41:19,010 --> 00:41:21,640
li meta nikbru għal wieħed fliexken tal-birra, jien ma jkollhom

1023
00:41:21,640 --> 00:41:23,300
ma joqogħdu jinkwetaw dwar il-grammatika Ingliża.

1024
00:41:23,300 --> 00:41:25,790
Iżda nistgħu wkoll jiffissaw dan bi ftit ta 'jekk

1025
00:41:25,790 --> 00:41:26,910
kondizzjoni, forsi.

1026
00:41:26,910 --> 00:41:30,110
Jekk dan in-numru huwa singular, imorru quddiem u jgħidu "flixkun",

1027
00:41:30,110 --> 00:41:31,840
inkella jekk huwa plural, jgħidu "fliexken".

1028
00:41:31,840 --> 00:41:34,150
Iżda għal issa, jien kompletament tqattigħ li kantuniera.

1029
00:41:34,150 --> 00:41:35,520
Mela ejja ara dak li konna ltqajna hawn.

1030
00:41:35,520 --> 00:41:37,150
Allura konna ltqajna xi kummenti fil-quċċata.

1031
00:41:37,150 --> 00:41:39,450
Jien inklużi dawn libreriji 2, kif

1032
00:41:39,450 --> 00:41:41,140
konna komunement ġew.

1033
00:41:41,140 --> 00:41:43,610
U issa let me iscroll sal-1

1034
00:41:43,610 --> 00:41:44,990
linji attwali ta 'kodiċi.

1035
00:41:44,990 --> 00:41:47,020
Linja 17 kicks off prinċipali.

1036
00:41:47,020 --> 00:41:50,610
Linja 21 u 20 għandha kemm fliexken tal-birra se jkun hemm?

1037
00:41:50,610 --> 00:41:52,060
U mbagħad I call GetInt.

1038
00:41:52,060 --> 00:41:53,800
U issa għandi daqsxejn ta 'verifika sanità.

1039
00:41:53,800 --> 00:41:57,030
>> Allura dan huwa konvenzjoni li aħna ser issa tibda tadotta biex

1040
00:41:57,030 --> 00:41:59,620
b'mod iktar rigoruż tiċċekkja input l-utent.

1041
00:41:59,620 --> 00:42:01,710
Kultant inti biss ma jridux li twassalhom għal darb'oħra

1042
00:42:01,710 --> 00:42:02,630
u għal darb'oħra u għal darb'oħra.

1043
00:42:02,630 --> 00:42:05,620
Jekk l-utent viti up u ma tikkoperax, multa.

1044
00:42:05,620 --> 00:42:07,430
Nieqaf u biss ma jittrattaw magħhom.

1045
00:42:07,430 --> 00:42:08,990
U hekk dan huwa dak li qed nagħmel hawn.

1046
00:42:08,990 --> 00:42:12,520
Jekk n huwa inqas minn 1, jien biss ser Yell fil-utent,

1047
00:42:12,520 --> 00:42:14,330
"Jiddispjacini, li jagħmel ebda sens." U mbagħad jien ser

1048
00:42:14,330 --> 00:42:16,650
arbitrarjament ritorn 1.

1049
00:42:16,650 --> 00:42:18,550
Għalhekk għal darb'oħra, din hija biss konvenzjoni biex jidraw.

1050
00:42:18,550 --> 00:42:19,850
Għal issa, teħodha fuq fidi.

1051
00:42:19,850 --> 00:42:22,700
Imma sa issa, aħna dejjem kelli qed jirritornaw 0, għaliex

1052
00:42:22,700 --> 00:42:25,204
konna qal li jirritornaw 0 ifisser, liema?

1053
00:42:25,204 --> 00:42:26,000
UDJENZA: Suċċess.

1054
00:42:26,000 --> 00:42:27,320
DAVID J. Malan: Suċċess, li kollox.

1055
00:42:27,320 --> 00:42:29,740
Allura issa li aħna qed finalment jibdew jaħsbu dwar

1056
00:42:29,740 --> 00:42:31,330
mhux suċċessi -

1057
00:42:31,330 --> 00:42:33,760
fi kliem ieħor, il-każijiet kantuniera, kondizzjonijiet ta 'żball -

1058
00:42:33,760 --> 00:42:37,520
Issa I jkollhom provvista infinita, jew għall-inqas 4000000000

1059
00:42:37,520 --> 00:42:39,790
affarijiet possibbli li jistgħu imorru ħażin fil-programmi tiegħi.

1060
00:42:39,790 --> 00:42:42,300
U nista 'tibda tassenja magħhom numri individwali.

1061
00:42:42,300 --> 00:42:44,340
Issa, ġeneralment huwa biżżejjed li biss jirritorna

1062
00:42:44,340 --> 00:42:45,730
għajr 0 xi ħaġa.

1063
00:42:45,730 --> 00:42:48,040
Allura aħna qed tmur biex sempliċement lura 1 għal issa.

1064
00:42:48,040 --> 00:42:51,440
Iżda r-raġuni għar-ritorn 1 huwa li hekk kif inti tirritorna

1065
00:42:51,440 --> 00:42:55,110
1, raden dak li jiġri għall-bqija tal-programm?

1066
00:42:55,110 --> 00:42:55,720
Huwa jwaqqaf.

1067
00:42:55,720 --> 00:42:56,560
Li minnu.

1068
00:42:56,560 --> 00:42:59,150
Allura l-fatt li jien lura 1 hija effettivament

1069
00:42:59,150 --> 00:43:02,950
qasir circuiting esekuzzjoni dan il-programm sabiex

1070
00:43:02,950 --> 00:43:06,780
xejn taħt il-linja 27 se jkompli jeżegwixxi.

1071
00:43:06,780 --> 00:43:09,210
Hekk kif prospetti prinċipali, li huwa.

1072
00:43:09,210 --> 00:43:13,160
>> Kull dritt, hekk jekk l-utent ma jikkopera u nilħqu linja 30

1073
00:43:13,160 --> 00:43:15,680
minħabba li ittajpjat fil-numru leġittimu, hawnhekk huwa tiegħi

1074
00:43:15,680 --> 00:43:16,990
implimentazzjoni ta 'dan il-kanzunetta.

1075
00:43:16,990 --> 00:43:19,050
So I ewwel jistampa karattru newline, biss għall-

1076
00:43:19,050 --> 00:43:19,880
estetika.

1077
00:43:19,880 --> 00:43:21,500
I issa għandhom biex loop.

1078
00:43:21,500 --> 00:43:22,930
U l-avviż qed nagħmel l-affarijiet fi ftit

1079
00:43:22,930 --> 00:43:23,880
ta 'direzzjoni differenti.

1080
00:43:23,880 --> 00:43:26,210
I ma jkollhom jagħmlu inqas minn, jien ma jkollhom jagħmlu + +.

1081
00:43:26,210 --> 00:43:30,660
Nista 'ngħid minflok initialize varjabbli i, huwa stabbilit ugwali għal

1082
00:43:30,660 --> 00:43:35,080
n, in-numru l-utent ittajpjat fil, allura jagħmel dan li ġej, hekk

1083
00:43:35,080 --> 00:43:39,590
Sakemm i huwa akbar minn 0, allura i -

1084
00:43:39,590 --> 00:43:42,070
ladarba inti stajt lest iterazzjoni waħda ta 'dan loop.

1085
00:43:42,070 --> 00:43:44,310
Allura aħna jista 'joqgħod isfel bl-użu ta' għal loop ukoll.

1086
00:43:44,310 --> 00:43:47,520
Issa, dan huwa il-ġimgħa pjuttost 1 Jittieħed issa, ma printf.

1087
00:43:47,520 --> 00:43:51,770
Allura print "fliexken% d tal-birra fuq il-ħajt." Stampa d% "

1088
00:43:51,770 --> 00:43:54,990
fliexken tal-birra. "" Ħu 1 isfel, tgħaddiha madwar. "Stampa

1089
00:43:54,990 --> 00:43:58,880
"% Fliexken tal-birra d fuq il-ħajt." Allura huwa għadu d%, imma

1090
00:43:58,880 --> 00:44:02,770
tinnota li l-argument li printf qed tinbidel.

1091
00:44:02,770 --> 00:44:05,840
Wara l-virgola, għandi i, għaliex nixtieq ngħid 99.

1092
00:44:05,840 --> 00:44:08,590
Wara dan comma, għandi i, għaliex nixtieq ngħid 99.

1093
00:44:08,590 --> 00:44:14,030
Wara dan comma, għandi i - 1, għaliex nixtieq ngħid 98 fl

1094
00:44:14,030 --> 00:44:16,260
dan ewwel iterazzjoni, u oħrajn.

1095
00:44:16,260 --> 00:44:18,520
U issa stabbiliti hawn, I biss ikollhom xi kumment ftit stupid.

1096
00:44:18,520 --> 00:44:22,270
U mbagħad linja 42, I-ritorn 0 b'konvenzjoni, li jfisser li

1097
00:44:22,270 --> 00:44:23,650
kollox huwa okay.

1098
00:44:23,650 --> 00:44:24,490
>> Allura dak li jekk jien goofed?

1099
00:44:24,490 --> 00:44:26,350
Liema jista 'żball komuni hawn jkun?

1100
00:44:26,350 --> 00:44:29,200
Ukoll, jekk dak I aċċidentalment qal ukoll, I do jridu għadd

1101
00:44:29,200 --> 00:44:31,640
isfel għal 0, nixtieq 0 fliexken tal-birra fuq il-ħajt?

1102
00:44:31,640 --> 00:44:34,620
So I say, i huwa akbar minn jew ugwali għal 0.

1103
00:44:34,620 --> 00:44:38,920
X'qed jiġri li jkun il-sintomu li I issa tara jekk I recompile

1104
00:44:38,920 --> 00:44:41,173
beer1 u run?

1105
00:44:41,173 --> 00:44:42,120
UDJENZA: negattiva.

1106
00:44:42,120 --> 00:44:43,590
DAVID J. Malan: Yeah, huwa gonna go negattiv.

1107
00:44:43,590 --> 00:44:45,950
Dan huwa żball off mill-wieħed, oerhört

1108
00:44:45,950 --> 00:44:47,270
żball komuni tagħmel.

1109
00:44:47,270 --> 00:44:48,960
Ejja fil-fatt imorru lura għall-tieqa terminal u tagħmel dan

1110
00:44:48,960 --> 00:44:50,620
hawn, hekk nistgħu naraw aktar fi żmien.

1111
00:44:50,620 --> 00:44:53,280
Daħħal, 99 fliexken tal-birra.

1112
00:44:53,280 --> 00:44:56,580
Agħlaq, imma aħna marru dejjem hekk ftit wisq.

1113
00:44:56,580 --> 00:45:00,500
Aħna kanta l-kanzunetta wisq isfel, tali li aħna issa laqat il-

1114
00:45:00,500 --> 00:45:01,510
negattiv numru.

1115
00:45:01,510 --> 00:45:03,680
Għalhekk ma pjuttost xogħol.

1116
00:45:03,680 --> 00:45:06,450
>> Kull dritt, sabiex inkunu nistgħu faċilment jistabbilixxu li billi tmur lura għall-

1117
00:45:06,450 --> 00:45:07,650
mod kif kienet darba.

1118
00:45:07,650 --> 00:45:10,360
Imma liema huma xi opportunitajiet issa għal

1119
00:45:10,360 --> 00:45:11,190
titjib?

1120
00:45:11,190 --> 00:45:17,200
Well, let me miftuħa beer2.c u iscroll isfel hawn u tagħti

1121
00:45:17,200 --> 00:45:19,310
ħarsa lejn din il-verżjoni.

1122
00:45:19,310 --> 00:45:21,370
X'hemm-ewwel ħaġa li jumps fil inti bħala differenti

1123
00:45:21,370 --> 00:45:23,715
f'dan il-verżjoni hawn?

1124
00:45:23,715 --> 00:45:24,190
UDJENZA: [inaudible].

1125
00:45:24,190 --> 00:45:26,510
DAVID J. Malan: Yeah, sabiex l-ebda aktar i, minħabba li ġara

1126
00:45:26,510 --> 00:45:29,350
me inti taf liema, jien titlob lill-utent għal n, u allura jien

1127
00:45:29,350 --> 00:45:33,580
iffissar i ugwali għal n, u mbagħad jien jinbidlu i, imma jien qatt ma

1128
00:45:33,580 --> 00:45:34,590
jmissu n-ġdid.

1129
00:45:34,590 --> 00:45:37,390
Allura dak l-Heck kien il-punt ta 'inti-allokazzjoni ieħor 32

1130
00:45:37,390 --> 00:45:45,210
bits imsejħa i biss sabiex I jista 'jkollhom varjabbli differenti?

1131
00:45:45,210 --> 00:45:47,960
Allura f'dan il-każ, I tip ta 'irrikonoxxa li mhux meħtieġa

1132
00:45:47,960 --> 00:45:49,190
karatteristika tad-disinn.

1133
00:45:49,190 --> 00:45:52,730
U jien issa se ngħid filwaqt n hija akbar minn 0, mur

1134
00:45:52,730 --> 00:45:56,180
quddiem u jistampaw il-kanzunetta istess, jgħaddu n għall printf bħala l-

1135
00:45:56,180 --> 00:46:00,210
tieni argument, u n - 1 hekk kif it-tieni argument stabbiliti hawn.

1136
00:46:00,210 --> 00:46:02,930
U mbagħad fuq kull iterazzjoni ta 'dan loop, imorru quddiem u biss

1137
00:46:02,930 --> 00:46:05,080
decrement n innifsu.

1138
00:46:05,080 --> 00:46:06,960
Issa, funzjonalment, dan il-programm

1139
00:46:06,960 --> 00:46:08,010
se tkun identika.

1140
00:46:08,010 --> 00:46:10,730
Jekk I tip 99, n jibda fil 99.

1141
00:46:10,730 --> 00:46:12,890
I decrement, decrement, decrement, decrement.

1142
00:46:12,890 --> 00:46:15,875
Jien ser tikseb it-triq kollha sa "Waħda flixkun tal-birra fuq

1143
00:46:15,875 --> 00:46:16,740
il-ħajt, wieħed flixkun tal-birra.

1144
00:46:16,740 --> 00:46:18,020
Ħu waħda isfel, tgħaddiha madwar.

1145
00:46:18,020 --> 00:46:21,480
0 fliexken tal-birra fuq il-ħajt. "Il-end, minħabba I ma

1146
00:46:21,480 --> 00:46:23,200
jiksbu l-kundizzjoni korretta.

1147
00:46:23,200 --> 00:46:24,280
Huwa akbar minn 0.

1148
00:46:24,280 --> 00:46:26,220
I ma tagħmel dan l-iżball.

1149
00:46:26,220 --> 00:46:28,470
>> Allura li hija aħjar, verżjoni waħda jew verżjoni 2?

1150
00:46:31,380 --> 00:46:33,480
So I smajt mazz ta 'murmurings għal tnejn.

1151
00:46:33,480 --> 00:46:34,730
Għaliex tnejn?

1152
00:46:37,210 --> 00:46:38,225
X'hemm li?

1153
00:46:38,225 --> 00:46:39,215
UDJENZA: [inaudible].

1154
00:46:39,215 --> 00:46:40,070
DAVID J. Malan: Oh, okay.

1155
00:46:40,070 --> 00:46:42,870
Għalhekk mhux se jmorru taħt iż-0, iżda tiftakar, fil-verżjoni waħda, l-

1156
00:46:42,870 --> 00:46:45,870
verżjoni korretta oriġinali ma tmurx taħt iż-0 lanqas.

1157
00:46:45,870 --> 00:46:48,340
Mela ftakar li dan huwa l-verżjoni korretta.

1158
00:46:48,340 --> 00:46:51,630
Mela ejja s-inqas jqabblu l-żewġ verżjonijiet korretta.

1159
00:46:51,630 --> 00:46:53,300
X'hemm argument favur verżjoni

1160
00:46:53,300 --> 00:46:55,146
2 benessri, MMM, aħjar?

1161
00:46:55,146 --> 00:46:55,642
Yeah?

1162
00:46:55,642 --> 00:46:57,630
UDJENZA: Hija tuża l-ispazju inqas.

1163
00:46:57,630 --> 00:46:59,530
DAVID J. Malan: Okay, hekk dan juża l-ispazju inqas, id-dritt?

1164
00:46:59,530 --> 00:47:02,900
Billi verżjoni waħda użata 32 bits għal n, u mbagħad ieħor

1165
00:47:02,900 --> 00:47:07,680
32 bits għal i.

1166
00:47:07,680 --> 00:47:10,060
Verżjoni 2 biss użi 32 bits għal n, sabiex

1167
00:47:10,060 --> 00:47:11,700
jidher li jkun plus.

1168
00:47:11,700 --> 00:47:12,950
Ħsibijiet oħra?

1169
00:47:18,070 --> 00:47:21,520
Hawn xi ħadd tixtieq li jargumentaw favur wieħed?

1170
00:47:21,520 --> 00:47:22,070
Yeah?

1171
00:47:22,070 --> 00:47:25,240
UDJENZA: Inti għandek tuża linja żejda ta 'kodiċi għal n -.

1172
00:47:25,240 --> 00:47:26,090
>> DAVID J. Malan: Okay, żgur.

1173
00:47:26,090 --> 00:47:26,960
Allura li huwa ġust.

1174
00:47:26,960 --> 00:47:29,040
Allura dan biss, għall-inqas lili -

1175
00:47:29,040 --> 00:47:31,940
I mean, dan fil-fatt iħoss Messier ftit, il-fatt li

1176
00:47:31,940 --> 00:47:35,120
I ma jistgħux sort ta jirrappreżentaw kollha ta 'loġika tiegħi f'wieħed

1177
00:47:35,120 --> 00:47:38,030
linja sbieħ, il-linja għal, bħala l-linja ta 'bott.

1178
00:47:38,030 --> 00:47:40,240
Hawnhekk, I tip ta 'jkollha tindi fuq dan n -

1179
00:47:40,240 --> 00:47:41,120
fl-aħħar tal-linja, għax

1180
00:47:41,120 --> 00:47:42,550
huwa loġikament meħtieġa.

1181
00:47:42,550 --> 00:47:45,190
Iżda tip ta rubs me-mod żbaljat, sempliċement minħabba li

1182
00:47:45,190 --> 00:47:48,260
jidher separat mill-loġika ta 'l hawn, minkejja li,

1183
00:47:48,260 --> 00:47:49,430
għal darb'oħra, huwa neċessarju.

1184
00:47:49,430 --> 00:47:50,990
Ħsibijiet oħra?

1185
00:47:50,990 --> 00:47:51,490
Yeah?

1186
00:47:51,490 --> 00:47:52,740
UDJENZA: [inaudible].

1187
00:47:57,990 --> 00:47:58,350
>> DAVID J. Malan: Yeah.

1188
00:47:58,350 --> 00:48:00,730
Allura dak li jekk inti minflok, fl-aħħar tal-kanzunetta, riedu

1189
00:48:00,730 --> 00:48:02,950
jistampa mill-ġdid l-isem tal-kanzunetta?

1190
00:48:02,950 --> 00:48:05,660
Bħal "Grazzi għall-logħob 99 fliexken tal-birra", jew xi ħaġa

1191
00:48:05,660 --> 00:48:06,690
iblah bħal dik?

1192
00:48:06,690 --> 00:48:09,750
Iżda l-punt huwa, int riedu aċċess għall-valur oriġinali.

1193
00:48:09,750 --> 00:48:13,180
Il-fatt li inti stajt għaddew minn mutazzjoni jew mibdula n fuq kull

1194
00:48:13,180 --> 00:48:16,330
iterazzjoni u għalhekk meqruda valur oriġinali tiegħu

1195
00:48:16,330 --> 00:48:18,650
ifisser li inti biss ma tistax tagħmel dan fl-aħħar.

1196
00:48:18,650 --> 00:48:20,660
Issa, forsi, aħna kjarament ma trid tagħmel

1197
00:48:20,660 --> 00:48:21,450
li f'dan il-programm.

1198
00:48:21,450 --> 00:48:22,350
Allura quién?

1199
00:48:22,350 --> 00:48:23,630
Imma dak li ħafna punt validu.

1200
00:48:23,630 --> 00:48:25,520
U biex ikunu onesti, hemm verament ebda waħda

1201
00:48:25,520 --> 00:48:26,630
dritt risposta hawn.

1202
00:48:26,630 --> 00:48:28,740
Huma qed kemm ugwalment korretti.

1203
00:48:28,740 --> 00:48:30,210
I tista 'tiġi konvinta jew mod.

1204
00:48:30,210 --> 00:48:33,310
Jien se ngħid li, b'mod ġenerali, huwa prinċipju tajba jekk inti

1205
00:48:33,310 --> 00:48:36,030
talab lill-utent għal xi valur u inti maħżuna varjabbli

1206
00:48:36,030 --> 00:48:38,730
bħall n, biss tip ta 'fuq il-prinċipju, huwa probabbilment tajjeb

1207
00:48:38,730 --> 00:48:40,160
li jżomm li madwar.

1208
00:48:40,160 --> 00:48:43,400
U xi informazzjoni li inti tixtieq li jgħaddu minn mutazzjoni għal darb'oħra u għal darb'oħra, biss

1209
00:48:43,400 --> 00:48:46,030
tagħti lilek innifsek kopja ta 'dak il-varjabbli, biss sabiex inti

1210
00:48:46,030 --> 00:48:47,830
jkollhom aċċess għall-oriġinali.

1211
00:48:47,830 --> 00:48:51,040
Inti huma l-infiq 32 bits aktar, iżda r-realtà hija din

1212
00:48:51,040 --> 00:48:53,490
kompjuter, bħal, 2 gigabytes ta 'RAM dawn il-jiem,

1213
00:48:53,490 --> 00:48:55,310
u aħna qed quibbling aktar minn 32 bits?

1214
00:48:55,310 --> 00:48:56,320
Verament mhux tali big deal.

1215
00:48:56,320 --> 00:48:58,550
U anke fuq dan il-mezz hawn, ma 'nofs GIG jew

1216
00:48:58,550 --> 00:49:01,700
gigabyte ta 'RAM, 32 bit versus 64 bits,

1217
00:49:01,700 --> 00:49:02,920
mhux tali big deal.

1218
00:49:02,920 --> 00:49:05,890
Ċertament illum, li għaddej biex tkun mod megħlub mill-daqs

1219
00:49:05,890 --> 00:49:08,400
tal-programm innifsu, li se tkun diversi mijiet

1220
00:49:08,400 --> 00:49:10,890
kilobytes, jekk mhux megabytes ftit, dawn il-jiem.

1221
00:49:10,890 --> 00:49:13,550
>> Tħassib Allura raġonevoli, ebda waħda risposta dritt.

1222
00:49:13,550 --> 00:49:15,490
Imma l-anqas dawk huma l-ħsibijiet li għandhom jibdew

1223
00:49:15,490 --> 00:49:16,790
jgħaddu moħħok?

1224
00:49:16,790 --> 00:49:19,600
Minħabba fil pset 0, anke jekk aħna verament biss mistennija

1225
00:49:19,600 --> 00:49:22,340
korrettezza, jew għall-inqas jiċħad bugs varji li

1226
00:49:22,340 --> 00:49:25,440
inti jista 'jkollok ltaqgħu magħhom, kif aħna nimxu' l quddiem hu d-disinn,

1227
00:49:25,440 --> 00:49:27,910
se tkun aspett ieħor importanti, kemm tal-kitba kodiċi

1228
00:49:27,910 --> 00:49:29,770
u wkoll tagħna evalwazzjoni kodiċi.

1229
00:49:29,770 --> 00:49:32,310
U dan bl-inqas jagħtu maħsub li affarijiet bħal dan.

1230
00:49:32,310 --> 00:49:35,590
U biss minħabba xogħlijiet xi ħaġa ma jfissirx li huwa tajjeb,

1231
00:49:35,590 --> 00:49:37,130
ma jfissirx li huwa mfassla tajjeb.

1232
00:49:37,130 --> 00:49:38,820
U dan huwa wieħed mill-affarijiet l-inkarigati mir-tagħlim u

1233
00:49:38,820 --> 00:49:41,990
settijiet problema se tgħinna tease part matul iż-żmien.

1234
00:49:41,990 --> 00:49:45,020
>> Ukoll, dak dwar, ejja ngħidu, din il-verżjoni hawn?

1235
00:49:45,020 --> 00:49:49,090
Let me jagħmlu xi ħaġa ftit sexy hawn fil-mument.

1236
00:49:49,090 --> 00:49:50,740
Ewwel let me teħles minn dan.

1237
00:49:50,740 --> 00:49:54,120
U issa ejja tiffissa din il-kwistjoni grammatikali.

1238
00:49:54,120 --> 00:49:58,780
Allura f'dan il-verżjoni, nixtieq li jiffissaw il-grammatika sabiex,

1239
00:49:58,780 --> 00:50:02,460
aktar milli biss jgħidu i parenthetical, bħal "flixkun"

1240
00:50:02,460 --> 00:50:03,360
jew "fliexken" -

1241
00:50:03,360 --> 00:50:04,900
Ma rridx li tnaqqas dak kantuniera -

1242
00:50:04,900 --> 00:50:08,350
Nixtieq ukoll li dinamikament jistampa l-kelma "fliexken"

1243
00:50:08,350 --> 00:50:12,820
jew "flixkun", waqt li tuża placeholders dawn% s illum.

1244
00:50:12,820 --> 00:50:16,550
So I bżonn biex kundizzjonalment jiċċekkjaw liema huwa l-valur ta 'i.

1245
00:50:16,550 --> 00:50:19,590
U jekk huwa 1, nixtieq ngħid "flixkun", u jekk xejn huwa

1246
00:50:19,590 --> 00:50:23,115
inkella, nixtieq ngħid "fliexken". Mela ejja jipprova jagħmel dan.

1247
00:50:23,115 --> 00:50:31,340
Mela jekk i == 1, allura let me imorru quddiem u tiddikjara -

1248
00:50:31,340 --> 00:50:34,080
I ħtieġa string, so let me do s1 spag, għaliex dan huwa l-

1249
00:50:34,080 --> 00:50:36,070
string ewwel I kura dwar id-dritt issa.

1250
00:50:36,070 --> 00:50:40,980
Jien se ngħid "flixkun". U mbagħad, ejja ara, spag

1251
00:50:40,980 --> 00:50:43,110
s2 - u jien ser jispjegaw fejn jien ser fil-mument -

1252
00:50:43,110 --> 00:50:47,650
"Fliexken." Allura jfakkru li, f'din il-kanzunetta, għandna bżonn li jkunu kapaċi

1253
00:50:47,650 --> 00:50:50,580
li jistampaw affarijiet, żewġ kelmiet differenti potenzjalment.

1254
00:50:50,580 --> 00:50:53,590
Mela jekk inħarsu lura hawn, tinnota li meta nikbru biex

1255
00:50:53,590 --> 00:50:56,440
dan l-eżempju hawn, "żewġ fliexken tal-birra fuq il-ħajt,

1256
00:50:56,440 --> 00:50:59,490
żewġ fliexken tal-birra, tieħu waħda isfel, tgħaddiha madwar ", nixtieq

1257
00:50:59,490 --> 00:51:02,380
din il-linja 4 sa issa ngħid "1 flixkun tal-birra fuq il-

1258
00:51:02,380 --> 00:51:04,900
ħajt ". So I bżonn biex tiddeċiedi, ma nixtieq ngħid" fliexken "jew

1259
00:51:04,900 --> 00:51:07,780
"Flixkun"? Allura jien ser ngħid b'mod arbitrarju, id-dritt,

1260
00:51:07,780 --> 00:51:10,530
Jien ser issa tiddikjara varjabbli imsejjaħ s1, spag

1261
00:51:10,530 --> 00:51:13,830
waħda, li għaddej biex tikseb pplaggjat fil hawn u wkoll hawnhekk,

1262
00:51:13,830 --> 00:51:16,070
għaliex dawn il-kliem huma dejjem identiċi, biss minħabba l-

1263
00:51:16,070 --> 00:51:17,290
natura tal-kanzunetta.

1264
00:51:17,290 --> 00:51:20,100
U jien ser sejħa s2 kwalunkwe kelma nixtieq

1265
00:51:20,100 --> 00:51:21,560
eventwalment jidhru stabbiliti hawn.

1266
00:51:21,560 --> 00:51:25,530
Issa, litteralment, 99 darbiet minn 100, li għaddej biex tkun l-

1267
00:51:25,530 --> 00:51:28,820
istess fiż-żewġ ta 'dawn il-każijiet, għax 3 huwa plural, 2 huwa

1268
00:51:28,820 --> 00:51:30,200
plural, 4 huwa plural.

1269
00:51:30,200 --> 00:51:34,640
Iżda f'dan il-każ kantuniera, fejn irridu jiksbu għal 2 u mbagħad 1, jew

1270
00:51:34,640 --> 00:51:37,250
anki 1 u mbagħad 0, I bżonn din il-loġika.

1271
00:51:37,250 --> 00:51:41,020
So I jkollu jonfoq xi żmien fil-kodiċi tiegħi jkollna dan id-dritt.

1272
00:51:41,020 --> 00:51:47,530
Mela jekk jien tagħmel dan, jekk i == 1, imbagħad s1 stabbiliti ugwali għal "flixkun"

1273
00:51:47,530 --> 00:51:52,010
u s2 ugwali għal "fliexken", għaliex dan se jkun għal 1

1274
00:51:52,010 --> 00:51:56,340
flixkun, u dan se jkun għal 0 fliexken.

1275
00:51:56,340 --> 00:51:58,250
U dan hawn, dak ma dan jirrappreżenta?

1276
00:51:58,250 --> 00:51:59,780
Just biex ikunu ċari.

1277
00:51:59,780 --> 00:52:00,620
Dan huwa biss kumment.

1278
00:52:00,620 --> 00:52:03,730
Allura l-fatt li inti jista 'jkollhom waħda linja kummenti ifisser li inti

1279
00:52:03,730 --> 00:52:06,110
jistgħu jikkummentaw kodiċi tiegħek bħal dan, iżda ieħor komuni

1280
00:52:06,110 --> 00:52:09,050
paradigma, ukoll, hija li jekk inti għandek frażi super-qasir li

1281
00:52:09,050 --> 00:52:11,410
inti tixtieq li tqiegħed lilek innifsek u huwa biss aktar tinqara biex

1282
00:52:11,410 --> 00:52:13,270
dan id-dritt fl-aħħar tal-linja ta 'kodiċi, inti tista'

1283
00:52:13,270 --> 00:52:15,230
assolutament tagħmel xi ħaġa bħal din.

1284
00:52:15,230 --> 00:52:20,150
>> Allura issa dak li jekk nagħmel dan? Else jekk i ma tkunx ugwali għal 1.

1285
00:52:20,150 --> 00:52:21,620
Allura bang ugwali -

1286
00:52:21,620 --> 00:52:23,150
punt exclamation huwa magħruf bħala "bang".

1287
00:52:23,150 --> 00:52:25,080
Allura bang = 1.

1288
00:52:25,080 --> 00:52:28,530
Mela jekk i ma tkunx ugwali għal 1, x'għandi nagħmel minflok trid tagħmel?

1289
00:52:28,530 --> 00:52:31,700
Ukoll, l-ewwel kelma nixtieq li jkun dak li?

1290
00:52:34,620 --> 00:52:40,030
Allura string 1 għandu jkun "fliexken" għall-fliexken plural,

1291
00:52:40,030 --> 00:52:42,440
u allura dan se jkun "fliexken" plural kif ukoll, għal issa.

1292
00:52:42,440 --> 00:52:43,800
U aħna ser tara jekk din attwalment gets ahna

1293
00:52:43,800 --> 00:52:44,870
fejn irridu imorru.

1294
00:52:44,870 --> 00:52:47,680
Allura issa jekk jien iscroll stabbiliti hawn, avviż li jien fejn jitwaħħal fil

1295
00:52:47,680 --> 00:52:50,170
mhux biss i, imma s1.

1296
00:52:50,170 --> 00:52:51,860
Jien fejn jitwaħħal fl-i u s1.

1297
00:52:51,860 --> 00:52:54,440
U mbagħad stabbiliti hawn, jien minus 1, li hija l-istess bħal

1298
00:52:54,440 --> 00:52:55,920
qabel, iżda. s2

1299
00:52:55,920 --> 00:52:58,730
Fi kliem ieħor, I jridu li l-kelma Ingliża għall-bidla li hi bbażata

1300
00:52:58,730 --> 00:52:59,930
fuq din il-loġika.

1301
00:52:59,930 --> 00:53:03,310
Issa, hemm diġà xi problemi f'dan il-kodiċi.

1302
00:53:03,310 --> 00:53:08,460
X'inhu maqsuma diġà barra tal-bieb hawn?

1303
00:53:08,460 --> 00:53:10,796
Yeah?

1304
00:53:10,796 --> 00:53:13,210
UDJENZA: [inaudible].

1305
00:53:13,210 --> 00:53:13,800
>> DAVID J. Malan: Eżattament.

1306
00:53:13,800 --> 00:53:16,030
Allura stajt diġà kisru l-lezzjoni ta 'ambitu.

1307
00:53:16,030 --> 00:53:19,610
Allura stajt iddikjarat s1 u s2, imma jien ghamilt dan ġewwa tal

1308
00:53:19,610 --> 00:53:22,980
ċineg kaboċċi, li jfisser yeah, dan il-kodiċi se taħdem up

1309
00:53:22,980 --> 00:53:27,430
sakemm linja 42, iżda hekk kif I hit-linja 43, raden liema l-ebda

1310
00:53:27,430 --> 00:53:28,900
jkunx għadu jeżisti?

1311
00:53:28,900 --> 00:53:32,600
Ukoll, raden x'hemm m'għadhomx fl-iskop - la s1 jew s2.

1312
00:53:32,600 --> 00:53:33,780
Allura aħna għandna biex jiffissaw dan.

1313
00:53:33,780 --> 00:53:36,180
So let me tħassar id-dikjarazzjonijiet.

1314
00:53:36,180 --> 00:53:39,320
U jien ser iħallu l-ismijiet varjabbli u ħassar dan hawn

1315
00:53:39,320 --> 00:53:40,120
u ħassar dan hawn.

1316
00:53:40,120 --> 00:53:43,557
U f'liema linji għandhom I really niddikjara dawn l-affarijiet?

1317
00:53:43,557 --> 00:53:44,960
UDJENZA: [inaudible].

1318
00:53:44,960 --> 00:53:45,410
DAVID J. Malan: Yeah, hekk probabbilment

1319
00:53:45,410 --> 00:53:46,850
dritt up hawn, 33-ish.

1320
00:53:46,850 --> 00:53:50,670
Allura s1 spag u mbagħad string s2.

1321
00:53:50,670 --> 00:53:51,950
U jirriżulta, I tista 'tagħmel dan.

1322
00:53:51,950 --> 00:53:54,260
Jekk int tiddikjara żewġ varjabbli ta 'l-istess tip,

1323
00:53:54,260 --> 00:53:57,420
inti tista 'attwalment biss użu virgola u tagħmel dan fi C. Kollha

1324
00:53:57,420 --> 00:53:58,970
dritt, hekk issa għandi żewġ varjabbli -

1325
00:53:58,970 --> 00:53:59,860
s1 u s2.

1326
00:53:59,860 --> 00:54:02,000
Jien assenjat lilhom valuri f'dawn

1327
00:54:02,000 --> 00:54:04,210
kondizzjonijiet hawn, jew fil hawn.

1328
00:54:04,210 --> 00:54:06,690
U mbagħad jien jużaw them down hawn taħt.

1329
00:54:06,690 --> 00:54:10,960
Kif ukoll dan huwa issa sejjer jaħdem?

1330
00:54:10,960 --> 00:54:12,740
>> Ukoll, huwa għadu Buggy ftit, imma ejja mill-inqas tara

1331
00:54:12,740 --> 00:54:13,730
kemm aħna ħadthom gotten.

1332
00:54:13,730 --> 00:54:16,500
So let me go quddiem u jagħmlu beer3.

1333
00:54:16,500 --> 00:54:17,695
Huwa dan beer3?

1334
00:54:17,695 --> 00:54:19,410
Yep, dan huwa beer3.

1335
00:54:19,410 --> 00:54:21,510
U issa let me imorru quddiem u run beer3.

1336
00:54:21,510 --> 00:54:23,820
399 99.

1337
00:54:23,820 --> 00:54:25,840
Nistgħu probabbilment skip ħafna minnhom.

1338
00:54:25,840 --> 00:54:29,100
U stabbiliti hawn, tħares lejn dak.

1339
00:54:29,100 --> 00:54:31,110
"Waħda flixkun tal-birra fuq il-ħajt, wieħed flixkun tal-birra, jieħdu

1340
00:54:31,110 --> 00:54:34,306
1 isfel, tgħaddiha madwar, 0 fliexken tal-birra fuq il-ħajt. "

1341
00:54:34,306 --> 00:54:37,570
Imma jien tiġbed l-attenzjoni tiegħek għal biss nofs tas-soluzzjoni.

1342
00:54:37,570 --> 00:54:39,620
Tip ta 'invitat up here.

1343
00:54:39,620 --> 00:54:43,030
Għalhekk jidher li l-każijiet kantuniera jinqalgħu meta i ugwali liema

1344
00:54:43,030 --> 00:54:44,030
żewġ valuri?

1345
00:54:44,030 --> 00:54:45,020
UDJENZA: 2, 1.

1346
00:54:45,020 --> 00:54:46,190
DAVID J. Malan: 2 u 1.

1347
00:54:46,190 --> 00:54:48,180
Mhuwiex 1 u mhux 1.

1348
00:54:48,180 --> 00:54:51,890
Huwa tassew biss dawn l-aħħar żewġ dramm ta 'dan il-kanzunetta.

1349
00:54:51,890 --> 00:54:53,890
Mela xi do I minflok trid tagħmel?

1350
00:54:53,890 --> 00:54:58,890
So I jidhru li qabdu l-każ fejn jekk i hija == għal 1,

1351
00:54:58,890 --> 00:55:02,240
allura l-ewwel kelma hija "flixkun", iżda l-kelma 2

1352
00:55:02,240 --> 00:55:07,230
huwa "fliexken". Iżda hawnhekk, nixtieq li tibdel dan ikun == 2.

1353
00:55:07,230 --> 00:55:08,570
U jekk dan huwa l-każ, dak li nixtieq l-

1354
00:55:08,570 --> 00:55:09,620
ewwel kelma li tkun?

1355
00:55:09,620 --> 00:55:10,430
UDJENZA: "Fliexken".

1356
00:55:10,430 --> 00:55:12,890
DAVID J. Malan: "Fliexken", hekk għal żewġ fliexken.

1357
00:55:12,890 --> 00:55:14,690
U allura din il-kelma hawnhekk għandhom ikunu -

1358
00:55:14,690 --> 00:55:15,340
UDJENZA: "Flixkun".

1359
00:55:15,340 --> 00:55:17,316
DAVID J. Malan: "Flixkun", singular.

1360
00:55:20,430 --> 00:55:25,160
>> Kull dritt, ejja zoom out, mur lura hawn fuq, mill-ġdid run jagħmlu,

1361
00:55:25,160 --> 00:55:28,590
-ripetizzjoni beer3, tip 99 darb'oħra.

1362
00:55:28,590 --> 00:55:30,710
Okay, "Segmentazzjoni tort (qalba mormi)."

1363
00:55:30,710 --> 00:55:32,780
What jiena jsir ħażin?

1364
00:55:36,050 --> 00:55:38,722
UDJENZA: Inti ma jkollhom valur [inaudible].

1365
00:55:38,722 --> 00:55:40,480
DAVID J. Malan: Ah, punt eċċellenti.

1366
00:55:40,480 --> 00:55:43,310
Kull dritt, hekk x'hemm ħażin hawn?

1367
00:55:43,310 --> 00:55:45,450
Allura tort segmentazzjoni, u aħna qed attwalment għaddejjin biex tara

1368
00:55:45,450 --> 00:55:49,020
dan pjuttost ftit drabi fil-futur, deliberatament.

1369
00:55:49,020 --> 00:55:51,030
Iżda għal issa, dak ma dan fil-fatt jfisser?

1370
00:55:51,030 --> 00:55:53,620
A tort segmentazzjoni kważi dejjem ifisser li inti għandek

1371
00:55:53,620 --> 00:55:56,760
b'xi ppruvat taċċessa, memorja RAM fil-kompjuter tiegħek,

1372
00:55:56,760 --> 00:56:00,600
li inti ma stess, li inti ma attwalment staqsa lill-

1373
00:56:00,600 --> 00:56:02,050
sistema operattiva għal.

1374
00:56:02,050 --> 00:56:04,440
Allura f'dan il-każ, l-avviż dak li jien ghamilt, li huwa

1375
00:56:04,440 --> 00:56:05,870
difettuż fil-loġika tiegħi.

1376
00:56:05,870 --> 00:56:09,500
Għandi assenjati s1 u s2 valur jekk i huwa ugwali għal 1.

1377
00:56:09,500 --> 00:56:11,590
Stajt ukoll isir li jekk i ugwali 2.

1378
00:56:11,590 --> 00:56:13,710
Imma jien ma sar fin-numru infinit ta 'oħrajn

1379
00:56:13,710 --> 00:56:14,690
possibbiltajiet -

1380
00:56:14,690 --> 00:56:17,940
b'mod partikolari, 3 jew 4 jew dot, dot, dot, 99.

1381
00:56:17,940 --> 00:56:20,100
Allura wieħed jiffissaw għal dan jista 'jkun biss ejja

1382
00:56:20,100 --> 00:56:22,190
ikollhom kundizzjoni ieħor.

1383
00:56:22,190 --> 00:56:26,780
U let me go fil hawn u ngħid s1 ugwali -

1384
00:56:26,780 --> 00:56:28,180
liema għandu jkun hawn?

1385
00:56:28,180 --> 00:56:28,750
UDJENZA: [inaudible].

1386
00:56:28,750 --> 00:56:30,460
>> DAVID J. Malan: "Fliexken", minħabba li fil-każ komuni,

1387
00:56:30,460 --> 00:56:32,020
huwa biss l-istess ħaġa.

1388
00:56:32,020 --> 00:56:35,580
Allura ugwali, kwotazzjoni unquote, "fliexken." Allura għal plural

1389
00:56:35,580 --> 00:56:41,010
fliexken, u mbagħad up hawn, għall-fliexken plural.

1390
00:56:41,010 --> 00:56:44,580
Okay, hekk issa let me jmorru lura għall-tieqa terminal tiegħi,

1391
00:56:44,580 --> 00:56:47,200
recompile, ri-run.

1392
00:56:47,200 --> 00:56:48,440
99.

1393
00:56:48,440 --> 00:56:49,150
Whew.

1394
00:56:49,150 --> 00:56:50,610
U ejja tagħmel verifika sanità malajr.

1395
00:56:50,610 --> 00:56:52,400
Teknikament, aħna'd tixtieq li taqra kollha ta 'dawn biex tiżgura

1396
00:56:52,400 --> 00:56:53,370
dawn qed korretti, imma ejja nħarsu lejn

1397
00:56:53,370 --> 00:56:54,640
inqas l-ħatja magħrufa.

1398
00:56:54,640 --> 00:56:57,370
3 fliexken, 2 fliexken, 2 fliexken, 1

1399
00:56:57,370 --> 00:57:00,380
flixkun, flixkun 1, 0 fliexken.

1400
00:57:00,380 --> 00:57:03,080
Aħna jidhru li għall-inqas iffissat għal issa.

1401
00:57:03,080 --> 00:57:06,010
Iżda l-qabda hawnhekk hija li dak mess god orribbli li dan huwa

1402
00:57:06,010 --> 00:57:07,470
biss biex issolvi stupid

1403
00:57:07,470 --> 00:57:09,540
one-karattru grammatikali dettall.

1404
00:57:09,540 --> 00:57:11,150
Allura hemm tip ta 'raġuni li I cut dan kantuniera

1405
00:57:11,150 --> 00:57:14,090
qabel, għaliex dan huwa biss kompletament annoying li jkollhom biex

1406
00:57:14,090 --> 00:57:15,020
jikteb dan il-kodiċi ħafna.

1407
00:57:15,020 --> 00:57:17,530
Iżda jirriżulta li hemm modi ftit aktar eleganti ta '

1408
00:57:17,530 --> 00:57:20,110
jesprimi l-istess ħaġa eżatt.

1409
00:57:20,110 --> 00:57:22,040
U nistgħu nagħmlu dan kif ġej.

1410
00:57:22,040 --> 00:57:23,890
>> Let me leave dan fuq l-iskrin għal mument u

1411
00:57:23,890 --> 00:57:27,320
jintroduċu xi ħaġa magħrufa bħala operatur tenarji.

1412
00:57:27,320 --> 00:57:29,600
Dan huwa tip ta 'one-liner li jinsab biss maħsub biex jagħmlu tagħna

1413
00:57:29,600 --> 00:57:31,880
jgħix sexier ftit, kif imwiegħed.

1414
00:57:31,880 --> 00:57:33,130
U jien ser tagħmel dan kif ġej.

1415
00:57:33,130 --> 00:57:35,810
Agħti me string imsejjaħ s1, u let me

1416
00:57:35,810 --> 00:57:37,200
tassenja dan kif ġej.

1417
00:57:37,200 --> 00:57:39,900
(I == 1)?

1418
00:57:39,900 --> 00:57:47,820
"Flixkun", inkella "fliexken". String s2 gets (i == 2)?

1419
00:57:47,820 --> 00:57:52,670
"Flixkun", inkella "fliexken".

1420
00:57:52,670 --> 00:57:57,050
Allura x'inhi allura huwa d-differenza hawn?

1421
00:57:57,050 --> 00:57:59,370
Dawn iż-żewġ linji ta 'kodiċi, I jargumentaw, jista

1422
00:57:59,370 --> 00:58:02,200
tissostitwixxi dan mess kollu.

1423
00:58:02,200 --> 00:58:04,280
So I sejħa hija mess, sempliċement minħabba li tip ta 'rubs lili il-

1424
00:58:04,280 --> 00:58:05,940
mod żbaljat li huwa linji tant ta 'kodiċi.

1425
00:58:05,940 --> 00:58:06,650
Mhux ħażin.

1426
00:58:06,650 --> 00:58:07,700
Mhuwiex disinn ħażin.

1427
00:58:07,700 --> 00:58:10,140
Bħal, dan huwa perfettament korrett u perfettament multa.

1428
00:58:10,140 --> 00:58:12,970
Iżda kodifikazzjoni gets tedious jekk ikollok li tesprimi lilek innifsek sabiex

1429
00:58:12,970 --> 00:58:15,530
kkritikat b'mod speċifiku għal darb'oħra u għal darb'oħra u għal darb'oħra ma 'sempliċi

1430
00:58:15,530 --> 00:58:16,620
Xenarju bħal dan.

1431
00:58:16,620 --> 00:58:19,470
Allura C għandha xi shortcuts, bħal dan.

1432
00:58:19,470 --> 00:58:24,270
Allura dan essenzjalment huwa qal jiddikjara string imsejjaħ s1 u

1433
00:58:24,270 --> 00:58:32,610
tassenja dan jew dan il-valur jew dan il-valur jekk i huwa == -

1434
00:58:32,610 --> 00:58:35,290
sorry, I għandha tgħid dan b'mod aktar ċar.

1435
00:58:35,290 --> 00:58:41,680
Tiddikjara a s1 varjabbli, tassenja dan il-valur, jekk dan huwa veru.

1436
00:58:41,680 --> 00:58:44,280
Inkella, tassenja dan il-valur.

1437
00:58:44,280 --> 00:58:47,220
Allura fi kliem ieħor, dan huwa tip ta 'mod wieħed linja ta'

1438
00:58:47,220 --> 00:58:51,490
qal jekk inkella iżda jagħmlu l-assenjazzjoni tul it-triq.

1439
00:58:51,490 --> 00:58:55,540
Mela jekk i huwa 1, imbagħad imorru quddiem u sejħa dan "flixkun". U

1440
00:58:55,540 --> 00:58:59,830
allura din inkella, sejħa hija "fliexken". Sadanittant, s2, il-

1441
00:58:59,830 --> 00:59:04,060
tieni kelma li għandna bżonn biex jiddefinixxu, jekk i ugwali 2, aħna ser

1442
00:59:04,060 --> 00:59:08,350
stabbiliti s2 għal "flixkun". Inkella, tistabbilixxi li "fliexken". U liema

1443
00:59:08,350 --> 00:59:11,460
dan ifisser issa huwa I tista 'tmur permezz ta' dan u ħassar kollha ta '

1444
00:59:11,460 --> 00:59:12,860
dawk il-linji ta 'kodiċi.

1445
00:59:12,860 --> 00:59:17,220
U meta ngħid, xi ftit ridiculously, li issa din hija

1446
00:59:17,220 --> 00:59:20,060
sexier, huwa sexier fil-tip ta 'sens stilistiċi.

1447
00:59:20,060 --> 00:59:22,660
Il-fatt li funzjonalment, dan il-kodiċi huwa attwalment għaddejjin biex

1448
00:59:22,660 --> 00:59:24,610
jagħmlu l-istess ħaġa eżatt.

1449
00:59:24,610 --> 00:59:26,890
U anki jekk jista 'tfittex ftit cryptic fl-ewwel

1450
00:59:26,890 --> 00:59:29,250
t'għajn, għaliex aħna stajt ma rajt dan tibni qabel, I d

1451
00:59:29,250 --> 00:59:31,850
jargumentaw li huwa finalment se tkun daqstant aktar

1452
00:59:31,850 --> 00:59:34,820
tinqara u għalhekk ħafna aktar faċli għall aħna bnedmin li tip ta '

1453
00:59:34,820 --> 00:59:36,830
jifhmu, għaliex issa inti tista 'biss taqra l-

1454
00:59:36,830 --> 00:59:38,830
kodiċi kollha fuq linja waħda.

1455
00:59:38,830 --> 00:59:41,550
Huwa għadu simili fl-ispirtu għal l-jekk, meta dan ikun

1456
00:59:41,550 --> 00:59:44,920
kundizzjoni u allura dan huwa x'hemm ġewwa l-jekk u dan

1457
00:59:44,920 --> 00:59:46,480
huwa x'hemm ġewwa l-ieħor.

1458
00:59:46,480 --> 00:59:49,450
Iżda nistgħu nagħmlu dan biss ħafna aktar elegantly.

1459
00:59:49,450 --> 00:59:52,650
>> U jekk I issa mur lura għall-terminal tiegħi, wara li titħassar kull

1460
00:59:52,650 --> 00:59:55,530
ta 'dawk il-linji u sostitwiti bl biss dawn iż-żewġ,

1461
00:59:55,530 --> 01:00:00,150
recompile, ri-run fliexken tal-birra ma '99, avviż li tiegħi

1462
01:00:00,150 --> 01:00:03,350
grammatika hija, fil-fatt, xorta korretta.

1463
01:00:03,350 --> 01:00:06,160
Għalhekk għal darb'oħra, xi ħaġa biex tibda.

1464
01:00:06,160 --> 01:00:08,840
2 fliexken tal-birra, 1 flixkun tal-birra.

1465
01:00:08,840 --> 01:00:09,370
Jistenna dritt.

1466
01:00:09,370 --> 01:00:10,100
Yeah.

1467
01:00:10,100 --> 01:00:13,900
Allura hemm għandna soluzzjoni konċiża ħafna aktar.

1468
01:00:13,900 --> 01:00:16,020
Allura dan, wisq, kif ikollok aktar komda ma 'C, mhux

1469
01:00:16,020 --> 01:00:18,630
neċessarjament ma 'l-pset ewwel jew saħansitra tieni, iżda

1470
01:00:18,630 --> 01:00:21,170
jirrealizzaw li dawn constructs jistgħu jippermettu magħna biex tagħmel affarijiet li qatt

1471
01:00:21,170 --> 01:00:22,810
aktar elegantly.

1472
01:00:22,810 --> 01:00:25,200
Issa ejja tagħmel ħaġa waħda oħra hawn.

1473
01:00:25,200 --> 01:00:31,460
Let me imorru quddiem u tiftaħ return1.c.

1474
01:00:31,460 --> 01:00:34,340
Issa ejja nibdew biex isolvu problema oħra b'mod li

1475
01:00:34,340 --> 01:00:37,140
jippermetti li jikteb il-kodiċi aktar sofistikati.

1476
01:00:37,140 --> 01:00:39,960
>> Allura hawnhekk programm ftit sempliċi li l-għan fil-ħajja

1477
01:00:39,960 --> 01:00:41,870
huwa li inkrement valuri.

1478
01:00:41,870 --> 01:00:43,100
U fil-fatt, ejja jieħu pass lura.

1479
01:00:43,100 --> 01:00:44,400
Let me tagħmel dan manwalment.

1480
01:00:44,400 --> 01:00:52,200
Let me do jinkludu u int prinċipali (vojt).

1481
01:00:52,200 --> 01:00:53,450
U let me sejħa dan increment.c.

1482
01:00:57,150 --> 01:00:58,570
U dak li nixtieq do?

1483
01:00:58,570 --> 01:01:02,240
Jien ser jimxi 'l quddiem u ngħid xi ħaġa simili -

1484
01:01:02,240 --> 01:01:04,280
se nitolbu-numri l-istess -

1485
01:01:04,280 --> 01:01:04,980
x int.

1486
01:01:04,980 --> 01:01:13,670
Allura x int gets 2; x printf hija% d, linja ġdida, x.

1487
01:01:13,670 --> 01:01:16,780
Allura jien ittajpjar malajr, iżda tip ta 'għalf familjari issa.

1488
01:01:16,780 --> 01:01:18,830
Imbagħad jien ser tagħmel x + +.

1489
01:01:18,830 --> 01:01:21,710
Imbagħad jien ser jistampaw din is-sentenza istess mill-ġdid.

1490
01:01:21,710 --> 01:01:24,550
U mbagħad jien ser jirritorna 0 biss biex nieqaf-programm.

1491
01:01:24,550 --> 01:01:25,960
Kull dritt, hekk li dan huwa programm li

1492
01:01:25,960 --> 01:01:26,960
inkrementi numru.

1493
01:01:26,960 --> 01:01:29,830
Huwa 1 ser initialize xi ħaġa għal 2, u allura huwa

1494
01:01:29,830 --> 01:01:33,470
se inkrement dan u jistampaw mill-ġdid.

1495
01:01:33,470 --> 01:01:36,930
>> Mela ejja jimxu inkrement, programm oerhört sempliċi.

1496
01:01:36,930 --> 01:01:40,940
Imma ejja ngħidu issa li nixtieq li kubu il-valur, sabiex jagħmlu

1497
01:01:40,940 --> 01:01:42,490
kemmxejn arbitrarja xi ħaġa.

1498
01:01:42,490 --> 01:01:45,140
U jien fil-fatt tixtieq li tagħmel x gets-kubu ta 'dan.

1499
01:01:45,140 --> 01:01:47,570
So I jistgħu jużaw dak li jissejjaħ il-funzjoni Pow, imma jien ma

1500
01:01:47,570 --> 01:01:48,650
verament jafu fejn dan ikun għadu.

1501
01:01:48,650 --> 01:01:50,580
Allura jien ser jagħmlu dan il-mod ta 'dari.

1502
01:01:50,580 --> 01:01:54,550
x drabi din hija ugwali għal x drabi x-ħinijiet x.

1503
01:01:54,550 --> 01:01:56,880
Allura jien cubing il-valur, multiplikat bl nnifisha mill-ġdid

1504
01:01:56,880 --> 01:02:00,440
u għal darb'oħra u għal darb'oħra, sabiex inkunu jiksbu l-poter

1505
01:02:00,440 --> 01:02:02,050
tat-3 f'dan il-każ.

1506
01:02:02,050 --> 01:02:06,000
Allura issa n-numri I għandhom jistampaw għandhom ikunu, kif Ser naraw

1507
01:02:06,000 --> 01:02:08,450
hawn - jagħmlu inkrement, dan huwa attwalment mhux verament inkrement

1508
01:02:08,450 --> 01:02:10,260
aktar, iżda aħna ser tħalli l-isem biss -

1509
01:02:10,260 --> 01:02:11,590
2 u mbagħad 8.

1510
01:02:11,590 --> 01:02:17,670
Issa, aħna għandna l-bidu ta 'opportunità għall-irfinar

1511
01:02:17,670 --> 01:02:21,570
hawn, fejn dan il-ħaġa cubing ta multiplikazzjoni numru

1512
01:02:21,570 --> 01:02:24,680
minnu stess waħedha minnu stess iħoss bħal dan jista 'jkun biss

1513
01:02:24,680 --> 01:02:27,920
utli li jkollhom bħala funzjoni, iddeċieda xi ħadd ferm simili

1514
01:02:27,920 --> 01:02:30,430
snin ilu - taf, it-tip ta utli jekk wieħed minna tiltaqa stabbiliti

1515
01:02:30,430 --> 01:02:33,120
u jikteb printf sabiex il-bqija tad-dinja tista 'tagħmel użu minnha,

1516
01:02:33,120 --> 01:02:36,160
għaliex ma we joqogħdu bilqegħda u jiktbu funzjoni msejħa kubu

1517
01:02:36,160 --> 01:02:39,250
li ma dan cubing għalina hekk aħna ma jkollhomx għalfejn manwalment

1518
01:02:39,250 --> 01:02:41,500
timplimenta l-kunċett ta 'cubing valuri hawn?

1519
01:02:41,500 --> 01:02:44,040
>> Allura eżempju sempliċi, imma ejja imorru quddiem u l-użu dan huwa bħala

1520
01:02:44,040 --> 01:02:46,280
opportunità li jiktbu funzjoni tagħna stess.

1521
01:02:46,280 --> 01:02:49,110
Allura s'issa, konna biss użati prinċipali, u konna użati b'mod ieħor

1522
01:02:49,110 --> 01:02:51,780
funzjonijiet tan-nies, iżda aħna ma miktub tagħna stess.

1523
01:02:51,780 --> 01:02:52,650
Allura here we go.

1524
01:02:52,650 --> 01:02:56,330
Jien ser jimxi 'l quddiem u jiktbu funzjoni msejħa kubu.

1525
01:02:56,330 --> 01:02:58,490
U jien se jkollhom dan jieħu input.

1526
01:02:58,490 --> 01:03:02,070
Allura input tagħha se tkun numru sħiħ.

1527
01:03:02,070 --> 01:03:03,570
U dak hu li se jagħmlu?

1528
01:03:03,570 --> 01:03:08,500
Huwa ser tiddikjara output int = input ħinijiet input

1529
01:03:08,500 --> 01:03:09,880
ħinijiet input.

1530
01:03:09,880 --> 01:03:12,190
U allura huwa se jirritorna l-output.

1531
01:03:12,190 --> 01:03:14,500
U mbagħad I għandhom ikunu speċifiċi issa.

1532
01:03:14,500 --> 01:03:16,820
Din il-funzjoni se terġa 'lura int.

1533
01:03:16,820 --> 01:03:19,130
Allura hawnhekk allura huwa kif youd tikteb funzjonijiet tiegħek.

1534
01:03:19,130 --> 01:03:20,850
Inti l-ewwel tiddeċiedi x'inhu l-isem tal tiegħek

1535
01:03:20,850 --> 01:03:21,720
funzjoni se tkun.

1536
01:03:21,720 --> 01:03:23,964
U ġeneralment, xi ħaġa ta 'spjegazzjoni hija tajba, so I ser

1537
01:03:23,964 --> 01:03:25,060
sejħa hija kubu.

1538
01:03:25,060 --> 01:03:27,180
Imbagħad għandek tispeċifika dak li għaddej biex jirritornaw, x'hemm

1539
01:03:27,180 --> 01:03:28,240
produzzjoni tagħha se tkun.

1540
01:03:28,240 --> 01:03:29,595
U aħna ma jkollhom għażliet li ħafna għadhom.

1541
01:03:29,595 --> 01:03:32,260
Int, char, float, bool, sekwenza.

1542
01:03:32,260 --> 01:03:34,260
Għal issa, jien ser twaħħal ma 'int, minħabba I jriduhom

1543
01:03:34,260 --> 01:03:35,880
li jirritorna numru sħiħ.

1544
01:03:35,880 --> 01:03:38,770
Imbagħad għandek tispeċifika liema inputs tiegħu, jekk ikun hemm, ikunu.

1545
01:03:38,770 --> 01:03:41,570
U jekk kubu jieħu l-argument, jieħu xi ħaġa bejn

1546
01:03:41,570 --> 01:03:44,970
parentesi, inti għandek tagħti dan l-argument isem b'tali mod li

1547
01:03:44,970 --> 01:03:47,860
inti tista 'sejħa hija xi ħaġa int implimentazzjoni jew bil-miktub

1548
01:03:47,860 --> 01:03:50,550
din il-funzjoni, u inti għandek tagħtiha tip, li f'dan il-

1549
01:03:50,550 --> 01:03:51,810
każ se tkun int.

1550
01:03:51,810 --> 01:03:54,690
Allura fil-qosor, kubu huwa funzjoni li jieħu numru sħiħ

1551
01:03:54,690 --> 01:03:57,560
bħala input u l-prospetti ta 'numru sħiħ bħala output.

1552
01:03:57,560 --> 01:03:59,240
>> Allura dak li ma tagħmel ma 'dak l-input?

1553
01:03:59,240 --> 01:04:03,710
Ukoll, f'konformità 14, niddikjara output varjabbli imsejħa, u jien

1554
01:04:03,710 --> 01:04:07,410
tassenja din il-valur, il-ħinijiet input input ħinijiet input.

1555
01:04:07,410 --> 01:04:11,490
U mbagħad I ritorn output.

1556
01:04:11,490 --> 01:04:14,890
Allura kif nista jużaw dan allura?

1557
01:04:14,890 --> 01:04:19,210
What do I jibdlu dawn il-karattri enfasizzati fuq il-linja

1558
01:04:19,210 --> 01:04:21,006
7 li, do you think?

1559
01:04:21,006 --> 01:04:21,800
UDJENZA: [inaudible].

1560
01:04:21,800 --> 01:04:25,570
DAVID J. Malan: Yeah, hekk kubu ta 'x.

1561
01:04:25,570 --> 01:04:28,290
Allura x hija varjabbli, li jfisser li żżomm xi valur.

1562
01:04:28,290 --> 01:04:30,190
Fortunatament, huwa ta 'numru sħiħ tip.

1563
01:04:30,190 --> 01:04:34,280
U minħabba x hija int, li jfisser nista 'għaddih fil kubu.

1564
01:04:34,280 --> 01:04:39,500
U anki jekk jien prevalenti l-valur ta 'x bil-valur

1565
01:04:39,500 --> 01:04:42,780
ta 'x kubi, kif kien il-każ s'issa, kull meta tagħmel

1566
01:04:42,780 --> 01:04:46,150
jkollhom sinjal ugwali u linja ta 'kodiċi, l-għalf fuq il-lemin

1567
01:04:46,150 --> 01:04:49,090
gets esegwita u mbagħad gets assenjati lill-

1568
01:04:49,090 --> 01:04:50,150
valur fuq ix-xellug.

1569
01:04:50,150 --> 01:04:52,950
Allura l-ordni ta 'operazzjonijiet huwa kif aħna nittamaw.

1570
01:04:52,950 --> 01:04:56,620
Allura ma dan ix-xogħol?

1571
01:04:56,620 --> 01:04:58,410
Well, let me jinżlu hawn.

1572
01:04:58,410 --> 01:04:59,970
Let me tiftaħ tieqa terminal tiegħi.

1573
01:04:59,970 --> 01:05:03,610
Let me do jagħmlu inkrement, Ikteb.

1574
01:05:03,610 --> 01:05:07,140
"Dikjarazzjoni impliċiti ta 'kubu" funzjoni huwa invalidu

1575
01:05:07,140 --> 01:05:13,700
C99. "Bħala twarrib, C99 jirreferi għall-C-lingwa kif kien

1576
01:05:13,700 --> 01:05:16,790
definit fl-1999, li kienet aġġornament fuq il-verżjoni minn

1577
01:05:16,790 --> 01:05:19,360
1989, li huwa aġġornament fuq l-oriġinali.

1578
01:05:19,360 --> 01:05:21,740
Allura dak kollu li tfisser.

1579
01:05:21,740 --> 01:05:24,250
>> Allura dak ma jfisser li "dikjarazzjoni impliċita ta '

1580
01:05:24,250 --> 01:05:26,790
"kubu" funzjoni huwa invalidu? "Huwa dritt hawn.

1581
01:05:26,790 --> 01:05:28,430
Huwa hemm dritt fil-linja 12.

1582
01:05:28,430 --> 01:05:30,460
UDJENZA: [inaudible].

1583
01:05:30,460 --> 01:05:30,730
DAVID J. Malan: X'hemm li?

1584
01:05:30,730 --> 01:05:32,470
UDJENZA: Mhuwiex qabel.

1585
01:05:32,470 --> 01:05:33,540
DAVID J. Malan: Mhuwiex qabel.

1586
01:05:33,540 --> 01:05:34,740
Allura dan huwa l-ħaġa.

1587
01:05:34,740 --> 01:05:38,190
C huwa tip ta 'stupid, jew kompilaturi Ċ huma tip ta' stupid.

1588
01:05:38,190 --> 01:05:41,060
Huma verament biss tagħmel dak li jgħidulhom li jagħmlu.

1589
01:05:41,060 --> 01:05:44,770
U huma, b'mod partikolari, biss aqra top kodiċi tiegħek għal isfel,

1590
01:05:44,770 --> 01:05:45,620
xellug għal-lemin.

1591
01:05:45,620 --> 01:05:49,140
Allura jekk il-kumpilatur, clang, huwa qari kodiċi tiegħek, linja 1,

1592
01:05:49,140 --> 01:05:50,120
ċifri kif għandek tagħmel dan.

1593
01:05:50,120 --> 01:05:50,940
Oh, hawn taqa prinċipali.

1594
01:05:50,940 --> 01:05:53,000
Okay, let me imorru quddiem u tiddikjara x varjabbli.

1595
01:05:53,000 --> 01:05:54,160
Let me jistampaw xi ħaġa.

1596
01:05:54,160 --> 01:05:55,890
Linja 7, dak l-Heck huwa kubu?

1597
01:05:55,890 --> 01:05:58,230
Mhuwiex iddikjarat stdio.h.

1598
01:05:58,230 --> 01:06:00,950
Hija ma jiġu mal C. Għandi l-ebda idea x'għandek tagħmel.

1599
01:06:00,950 --> 01:06:03,960
U hekk clang biss bails u quits ma dak il-messaġġ ta 'żball.

1600
01:06:03,960 --> 01:06:05,850
Allura nistgħu jiffissaw dan fi ftit ta 'modi.

1601
01:06:05,850 --> 01:06:10,530
Nistgħu jgħallmu clang dak kubu huwa billi sempliċiment jiċċaqalqu fejn il-

1602
01:06:10,530 --> 01:06:11,820
dikjarazzjoni.

1603
01:06:11,820 --> 01:06:14,640
So I maqtugħa u pasted hija atop prinċipali.

1604
01:06:14,640 --> 01:06:17,770
Issa tirrealizza li sempliċiment għaliex prinċipali m'għadux l-ewwel, huwa

1605
01:06:17,770 --> 01:06:19,150
xorta esegwiti mill-kontumaċja.

1606
01:06:19,150 --> 01:06:20,060
Main hija ewlieni.

1607
01:06:20,060 --> 01:06:21,022
Hu l-isem funzjoni default.

1608
01:06:21,022 --> 01:06:22,930
Ma jimpurtax fejn fil-fajl.

1609
01:06:22,930 --> 01:06:26,910
Imma l-anqas issa clang rat kubu qabel I użu.

1610
01:06:26,910 --> 01:06:28,500
Mela ejja ara jekk clang huwa kuntenti issa.

1611
01:06:28,500 --> 01:06:31,410
Għamla inkrement, hija ma tiġbor dan iż-żmien.

1612
01:06:31,410 --> 01:06:33,060
>> Let me run inkrement.

1613
01:06:33,060 --> 01:06:34,810
U fil-fatt, jidher li tkun qed taħdem.

1614
01:06:34,810 --> 01:06:36,810
Issa, inti tista 'toħroġ bi xenarji eventwalment fejn

1615
01:06:36,810 --> 01:06:38,650
mhuwiex fattibbli li tqiegħed kull funzjoni

1616
01:06:38,650 --> 01:06:39,740
hawn fuq kull funzjoni oħra.

1617
01:06:39,740 --> 01:06:42,140
Int ser jeħlu f'dan loop infinita fir-realtà,

1618
01:06:42,140 --> 01:06:43,480
fejn dan Guy jixtieq li jkun hawn imma dan

1619
01:06:43,480 --> 01:06:44,390
Guy jeħtieġ li jkun hemm.

1620
01:06:44,390 --> 01:06:45,830
Allura li ma dejjem xogħol.

1621
01:06:45,830 --> 01:06:49,020
Allura Thankfully, C tkun soluzzjoni aktar eleganti.

1622
01:06:49,020 --> 01:06:50,790
Jien ser tpoġġi din lura fejn kien, biss minħabba I

1623
01:06:50,790 --> 01:06:53,390
jippreferu, bħala kwistjoni ta 'prinċipju, li ewlieni dejjem ikunu

1624
01:06:53,390 --> 01:06:55,550
fil-quċċata, għaliex huwa biss sbieħ biex tara dak li dan il-programm

1625
01:06:55,550 --> 01:06:56,920
ma b'mankanza.

1626
01:06:56,920 --> 01:06:58,950
U dak li jien ser tagħmel up hawnhekk huwa jiddikjara dak li sejjaħ

1627
01:06:58,950 --> 01:07:00,250
prototip.

1628
01:07:00,250 --> 01:07:05,730
Jien ser terġa 'tiddikjara funzjoni kubu tiegħi mill litteralment

1629
01:07:05,730 --> 01:07:07,180
ikkupjar u pasta.

1630
01:07:07,180 --> 01:07:08,290
Attwalment, li mhux litteralment.

1631
01:07:08,290 --> 01:07:13,060
Allura litteralment ikkupjar u pasta linja 15

1632
01:07:13,060 --> 01:07:15,160
up fuq linja 6.

1633
01:07:15,160 --> 01:07:17,010
Ma jimpurtax liema linja dan jispiċċa fuq.

1634
01:07:17,010 --> 01:07:18,380
Dan jiġri li jkun fuq il-linja 4.

1635
01:07:18,380 --> 01:07:19,950
Iżda dan ma għandhom ikunu qabel prinċipali.

1636
01:07:19,950 --> 01:07:21,150
Iżda avviż-differenza.

1637
01:07:21,150 --> 01:07:24,100
Linja 4 truf bil-punto virgola, li jfisser ħej,

1638
01:07:24,100 --> 01:07:27,510
Clang, tieħu kelma tiegħi għaliha li teżisti funzjoni

1639
01:07:27,510 --> 01:07:31,350
imsejħa kubu li jieħu int u jirritorna int.

1640
01:07:31,350 --> 01:07:33,020
Imma jien ma gonna jgħidlek dak li hu għadu.

1641
01:07:33,020 --> 01:07:35,180
Biss jafu li I wegħda li jgħidlek eventwalment.

1642
01:07:35,180 --> 01:07:38,490
U fil-fatt, issa huwa okay li dan huwa stabbiliti hawn taħt.

1643
01:07:38,490 --> 01:07:41,275
>> Allura dan huwa ġeneralment aħjar, għaliex imbagħad fil-quċċata tal-

1644
01:07:41,275 --> 01:07:44,240
fajl tiegħek, inti tista 'sempliċement Rattle off, rapidu-nar, linja waħda

1645
01:07:44,240 --> 01:07:46,470
kull wieħed, dak li l-ismijiet ta 'funzjonijiet tiegħek huma, liema tagħhom

1646
01:07:46,470 --> 01:07:49,120
inputs huma, liema riżultati tagħhom huma.

1647
01:07:49,120 --> 01:07:52,210
U biex ikunu aktar ċari, input ġeneralment tfisser argument jew

1648
01:07:52,210 --> 01:07:54,110
parametru, sinonimi.

1649
01:07:54,110 --> 01:07:56,890
Output ifisser il-valur tar-ritorn, dak ma

1650
01:07:56,890 --> 01:07:58,700
idejn lura lili.

1651
01:07:58,700 --> 01:08:03,420
Allura f'dan il-każ hawnhekk, kubi ġiet iddikjarata fil-quċċata, iżda

1652
01:08:03,420 --> 01:08:06,940
definiti, magħrufa wkoll bħala implimentati, fil-qiegħ.

1653
01:08:06,940 --> 01:08:09,620
Allura issa ejja mmorru lura hawn u jerġa 'jsir dan.

1654
01:08:09,620 --> 01:08:13,430
Allura issa let me go quddiem u jerġa 'jsir jagħmlu, jerġa' jsir inkrement.

1655
01:08:13,430 --> 01:08:16,500
U issa jidher li qed jaħdem biss multa.

1656
01:08:16,500 --> 01:08:19,450
Allura issa nistgħu jimxi 'l quddiem u fattur barra xi ħaġa bħall-

1657
01:08:19,450 --> 01:08:23,720
birra eżempju fis din il-verżjoni 4.

1658
01:08:23,720 --> 01:08:25,590
So let me iscroll hawn.

1659
01:08:25,590 --> 01:08:28,149
U avviż li jien tip ta 'ħa din il-lezzjoni lill-qalb heure.

1660
01:08:28,149 --> 01:08:31,140
Il-fatt li I kien kant stanza istess mill-ġdid u

1661
01:08:31,140 --> 01:08:34,130
ġdid u għal darb'oħra, il-linja kor istess fil-kanzunetta, feltru

1662
01:08:34,130 --> 01:08:36,439
simili għaliex ma I fattur li minn ġo funzjoni?

1663
01:08:36,439 --> 01:08:38,470
U fil-fatt, dan għandu jkun wieħed mill-motivazzjonijiet.

1664
01:08:38,470 --> 01:08:40,960
Minbarra l-fatt li xi ħadd ieħor fid-dinja tista 'tixtieq

1665
01:08:40,960 --> 01:08:42,390
li tuża l-funzjoni kubu -

1666
01:08:42,390 --> 01:08:44,560
li l-raġuni tajba għall-fattur xi ħaġa u jiktbu tiegħek

1667
01:08:44,560 --> 01:08:45,720
funzjoni custom stess -

1668
01:08:45,720 --> 01:08:48,720
jekk hemm blokki ta 'kodiċi fil-programm tiegħek li biss jagħmel

1669
01:08:48,720 --> 01:08:51,370
sens kunċettwali, li inti tip ta 'tixtieq li tagħtiha

1670
01:08:51,370 --> 01:08:53,740
isem - bħal f'dan il-każ, kor -

1671
01:08:53,740 --> 01:08:57,380
allura inti tista 'bl-istess mod jikteb dik bħala funzjoni separata.

1672
01:08:57,380 --> 01:08:59,560
Inti ma għandekx li tikteb kollox prinċipali jekk hija biss

1673
01:08:59,560 --> 01:09:02,609
iħoss aktar nodfa li tissepara dan jitwettaq u tagħtiha isem.

1674
01:09:02,609 --> 01:09:05,529
>> Allura f'dan il-każ hawnhekk, avviż li għandi kumment atop

1675
01:09:05,529 --> 01:09:06,859
din il-funzjoni li biss sings dwar il-

1676
01:09:06,859 --> 01:09:08,630
numri speċifiċi ta 'fliexken.

1677
01:09:08,630 --> 01:09:10,609
Avviż hawnhekk li jien ma bżonn tirrikorri dawn

1678
01:09:10,609 --> 01:09:12,520
affarijiet input u output.

1679
01:09:12,520 --> 01:09:16,090
Fil-fatt, din id-darba I biss imsejħa b input tiegħi għall-flixkun.

1680
01:09:16,090 --> 01:09:19,960
U l-avviż hawn, null jissuġġerixxi liema?

1681
01:09:19,960 --> 01:09:21,309
Dan kor -

1682
01:09:21,309 --> 01:09:22,660
UDJENZA: Ma lura.

1683
01:09:22,660 --> 01:09:23,870
DAVID J. Malan: Ma jerġax lura għal valur.

1684
01:09:23,870 --> 01:09:26,800
U fil-fatt, il-funzjonijiet ma jkollhomx għalfejn jirritornaw valuri.

1685
01:09:26,800 --> 01:09:28,060
Huma biss tista 'tagħmel xi ħaġa.

1686
01:09:28,060 --> 01:09:30,270
Huma jista 'jkollhom liema huma msejħa effetti sekondarji, li f'dan il-

1687
01:09:30,270 --> 01:09:33,109
każ huwa biss mazz sħiħ ta 'l-istampar fuq l-iskrin.

1688
01:09:33,109 --> 01:09:36,580
Allura avviż li dan il-kodiċi hawn, I litteralment biss seraq minn

1689
01:09:36,580 --> 01:09:37,680
ta 'qabel eżempju.

1690
01:09:37,680 --> 01:09:39,930
L-unika differenza hija minflok tintuża i kif tiegħi

1691
01:09:39,930 --> 01:09:42,890
varjabbli, jien issa jużaw b bħala varjabbli tiegħi.

1692
01:09:42,890 --> 01:09:45,880
So I jkollhom b stabbiliti hawn, għandi b stabbiliti hawn, għandi b

1693
01:09:45,880 --> 01:09:47,109
minus 1 stabbiliti hawn.

1694
01:09:47,109 --> 01:09:49,279
Iżda l-kodiċi huwa eżattament l-istess.

1695
01:09:49,279 --> 01:09:52,529
Iżda biss biex turi li inti issa kif nistgħu nużaw dan, let me go

1696
01:09:52,529 --> 01:09:56,780
quddiem u fil-fatt tbiddel din tkun għal loop.

1697
01:09:56,780 --> 01:10:03,850
għal (i int = n; i> n; i -).

1698
01:10:03,850 --> 01:10:06,230
>> Allura stajt misruqa li minn eżempju preċedenti tagħna.

1699
01:10:06,230 --> 01:10:08,970
Preċedentement, huwa konformi 37 li jiena bdew

1700
01:10:08,970 --> 01:10:10,640
kant dan kanzunetta tedjanti.

1701
01:10:10,640 --> 01:10:15,810
Iżda minflok, jien biss ser issa jitolbu kor ta 'i.

1702
01:10:15,810 --> 01:10:16,870
Magħmul.

1703
01:10:16,870 --> 01:10:20,260
Allura issa f'kull iterazzjoni ta 'dan loop, I call dan ieħor

1704
01:10:20,260 --> 01:10:22,220
, il-funzjoni kor, li I ġara li tikteb.

1705
01:10:22,220 --> 01:10:24,110
Ma kienx miktub minn xi ħadd ieħor sena ilu.

1706
01:10:24,110 --> 01:10:27,930
Iżda kor, sadanittant, użi printf għall-istampar

1707
01:10:27,930 --> 01:10:29,840
out dawn il-linji 4.

1708
01:10:29,840 --> 01:10:32,720
Imma l-fatt li jien ssejjaħ kor ġdid u għal darb'oħra fil-

1709
01:10:32,720 --> 01:10:35,900
loop ifisser li jien ser tikseb, fl-aħħar nett, il-

1710
01:10:35,900 --> 01:10:39,310
kanzunetta istess eżatt kif jien s'issa.

1711
01:10:39,310 --> 01:10:42,130
Allura fil-qosor, issa jekk I ħarsa lura lejn il-kodiċi tiegħi, anki jekk

1712
01:10:42,130 --> 01:10:44,240
funzjonalment din hija ekwivalenti, avviż li huwa

1713
01:10:44,240 --> 01:10:46,020
tibda tikseb saħansitra aktar leġġibbli.

1714
01:10:46,020 --> 01:10:48,410
I do not know kif eżattament GetInt

1715
01:10:48,410 --> 01:10:49,250
hija implimentata.

1716
01:10:49,250 --> 01:10:52,050
Franchement, I do not know kif kor tiġi implimentata.

1717
01:10:52,050 --> 01:10:52,970
Imma ma jimpurtax lili.

1718
01:10:52,970 --> 01:10:55,620
I ma 'kura, għax issa nista sort ta', bħala bniedem, moqri

1719
01:10:55,620 --> 01:10:57,050
din qiegħ minn fuq għal.

1720
01:10:57,050 --> 01:10:59,950
U minħabba l-funzjonijiet huma msemmija skond dak li

1721
01:10:59,950 --> 01:11:02,910
do, kodiċi tiegħi huwa dejjem tinqara.

1722
01:11:02,910 --> 01:11:05,190
U kif il-programmi tagħna jiksbu ħafna aktar kumpless -

1723
01:11:05,190 --> 01:11:07,220
sa tmiem is-semestru, inti ser tkun bil-miktub mijiet ta 'linji

1724
01:11:07,220 --> 01:11:10,970
tal-kodiċi fil-lingwi bħal PHP u JavaScript u simili -

1725
01:11:10,970 --> 01:11:13,550
inti ser issib li huwa daqstant faċli milli biex iżommu kont ta '

1726
01:11:13,550 --> 01:11:14,080
dak li inti ghamilt.

1727
01:11:14,080 --> 01:11:15,810
U meta tibda jikkollabora ma 'ħbieb jew

1728
01:11:15,810 --> 01:11:19,010
imsieħba jew kollegi, inti ser tkun tista 'tikteb ħafna aktar

1729
01:11:19,010 --> 01:11:22,910
programmi massivi billi jibdew jeżerċitaw dawn bażika

1730
01:11:22,910 --> 01:11:23,990
building blocks.

1731
01:11:23,990 --> 01:11:25,550
>> Allura ma 'dak imsemmi, għaliex ma aħna sejħa hija ta' kuljum?

1732
01:11:25,550 --> 01:11:27,190
U aħna se tara inti nhar l-Erbgħa.

1733
01:11:27,190 --> 01:11:33,611
[Applause]