C程序设计基础 英文版 课件 1.Chapter1 Introducing C

Chapter1IntroducingCFangWangOutlinesChapter1IntroducingC1.1WhyProgrammingisImportant1.2WhyShouldWeLearnC1.3HistoryofC1.4StrengthsandWeaknessesofC1.5HowDoWeLearnC21.1WhyProgrammingisImportant?BeusedtoCommunicateLanguage+ProgrammingCprogrammingLanguageisawidelyusedhighlevelcomputerlanguage.3Whatisit?ProgramminginCWriteprogramsMakecomputerworkforus.4WhyShouldWeLearnC?IsCtheonlyprogramminglanguage?52’’5WhyShouldWeLearnC?1+1indifferentlanguage6#include<stdio.h>intmain(){printf("%d\n",1+1);return0;}2.1WritingaSimpleProgramCompilingandLinkingBeforeaprogramcanbeexecuted,threestepsareusuallynecessary:Preprocessing.Thepreprocessorobeyscommandsthatbeginwith#(knownasdirectives)Compiling.Acompilerthentranslatestheprogramintomachineinstructions(objectcode).Linking.Alinker

combinestheobjectcodeproducedbythecompilerwithanyadditionalcodesneededtoyield

acompleteexecutableprogram.72.1WritingaSimpleProgramTheGCCCompilerGCCisoneofthemostpopularCcompilers.GCCissuppliedwithLinuxbutisavailableformanyotherplatformsaswell.82.1WritingaSimpleProgramIntegratedDevelopmentEnvironmentsAnintegrateddevelopmentenvironment(IDE)isasoftwarepackagethatmakesitpossibletoedit,compile,link,execute,anddebugaprogramwithoutleavingtheenvironment.9Howdoesitwork?WriteaprogramwithIDE（IntegratedDevelopmentEnvironment）Talk(xxx.corxxx.cpp)Compiletheprogramtoanexecutablefile–Translate(xxx.exe)Runtheexecutablefileoncomputer--Communicate101.3HistoryofCOriginsofCCisaby-productofUNIX,developedatBellLaboratoriesbyKenThompson,DennisRitchie,andothers.KenThompson

designedasmalllanguagenamedB,basedonBCPL.By1971,DennisRitchiebegantodevelopanextendedversionofB.HecalledhislanguageNB(“NewB”)atfirst.AsthelanguagebegantodivergemorefromB,hechangeditsnametoC.Thelanguagewasstableenoughby1973thatUNIXcouldberewritteninC.111.3HistoryofCStandardizationofC-------grammarK&RCDescribedinKernighanandRitchie,TheCProgrammingLanguage(1978)DefactostandardC89/C90ANSIstandardX3.159-1989(completedin1988;formallyapprovedinDecember1989)InternationalstandardISO/IEC9899:1990C99InternationalstandardISO/IEC9899:1999IncorporateschangesfromAmendment1(1995)121.3HistoryofCC-BasedLanguagesChasahugeinfluenceonmodern-dayprogramminglanguages.C++includesallthefeaturesofC,butaddsclassesandotherfeaturestosupportobject-orientedprogramming.JavaisbasedonC++andthereforeinheritsmanyCfeatures.C#isamorerecentlanguagederivedfromC++andJava.131.4StrengthsandWeaknessesofCStrengthsofCEasytocomprehendEfficiency:Cprogramcanrunquicklyandinlimitedamountsofmemory.CprogramsexecutemorequicklythanJavaandPythondo.Power:C’slargecollectionofdatatypesandoperatorshelpmakeitapowerfullanguage.

Portability:NottiedtoanyoneOperatingsystemormachineFlexibility:CimposesveryfewrestrictionsontheuseofitsfeaturesStandard

library:OneofC’sgreatstrengthsisitsstandardlibrary,whichcontainshundredsoffunctionsforinput/output,stringhandling,storageallocationandotherusefuloperations.141.2StrengthsandWeaknessesofCWeaknessesofCLackofobject-orientedprogrammingconceptsProgrammingskillsrequiredtolearn,sinceCProgramscanbeerror-prone.Programscanbedifficulttounderstand.Programscanbedifficulttomodify.LargeprogramswritteninCcanbehardtochangeiftheyhaven’tbeendesignedwithmaintenanceinmind.NotefficientascomparedtoPython.ThesyntaxofPythoniseasierAbsenceoftheconceptofnamespaceWithoutnamespaces,wecan’tdeclaretwofactors,likevariables,withthesamename.151.5Howtolearnit?PracticeisthemagicwordtolearnCKnowledge—learnthegrammar,keywordofC

programminglanguageSkill—learnhowtowrite,compileandrunC

program16Whenyoudon’tPRACTICECODEBLOCKSTheplacetowritethecode--codeblocksWheretowritethecode--codeblocksDownloadcodeblocksfromHowtouseit18Wheretowriteyourprogram------------CodeBlocks

1.Goto：/downloads2.Click“Downloadthebinaryrelease”3.

Pleaseselectasetuppackagedependingonyourplatform:

E.g.WeuseWINDOWS：

3.Pleaseselectasetuppackagedependingonyourplatform:E.g.WeuseWINDOWS：

Pleaseselect“codeblocks-20.03minGW-setup.exe”。ClickDownloadfrom"FossHUB"

or"S"(Theyarethesame).（IfyoucannotinstallCODEBLOCKS，thendownload“codeblocks-20.03mingw-nosetup.zip”.Youdon'thavetoinstallit,justdownloaditthenyoucanuseit.）

4.Afteryoudownloadthefiles,clickitandsetupCode::Blocks.Note：Code::Blockswillbeinstalledinthedefaultfolder“C:\ProgramFiles\CodeBlocks”.Youshouldchangetoanotherfolder.TheruleistoavoidusingSPACEorChinesecharactersintheinstallationpath.However,between“Program”and“Files”,thereisaspace.So,youshoulduseadifferentfolder.Click“Browse..."tochangethefolderyouinstallitin，E.g.Ichangetoc:\mysoftwareYoucaninstallitdirectlyattherootdirectoryofdiskCordiskD,etc.Youcanalsoinstallitinotherplaces.Forexample,youcancreateanewfoldercalled“mysoftware”onyourdiskDandinstallCode::Blocksinthisnewfolder.Click“Browse...”tochangethefolderyouwanttoinstallitin.Forexample,wecanchangeitto“C:\mysoftware\CodeBlocks”Nowyoucanusecoldclocks.

Ifyouinstallandunsetupitmanytimes,youmaymeetsomeerrorslike"Can'tfindtheGNUGCCCompiler".PleaseseemyAnnouncement”Can'tfindacompiler“232425Typethe

name

of

you