高级语言程序设计

2024/1/23BUPT-PRF1Lecture1

Introduction:Computers&Programming万岩2024/1/23BUPT-PRF2ContentComputerHistory&HardwareHistoryHardwareBits&BytesComponentsComputerSoftware&ProgrammingLanguageDevelopmentofC(Textbook1.1,1.2)2024/1/23BUPT-PRF3HistoryAtanasoff-BerryComputer(ABC,1937)HumanoperatormanipulatedexternalwiringElectricalNumericalIntegratorandComputer(ENIAC,1946)Vacuumtubes（电子管）MarkI(1944)Mechanicalrelayswitches（继电器开关）ElectronicDelayedStorageAutomaticComputer(EDSAC,1949)IncorporatedaformofmemoryTheprinciplewasdevelopedbyJohnVonNeumann2024/1/23BUPT-PRF4History：ElectricalNumericalIntegratorandComputer(ENIAC,1946)

-Vacuumtubes2024/1/23BUPT-PRF51.1ComputerHardwareComputersareconstructedfromphysicalcomponentsreferredtoasHardwareHardwarefacilitatesthestorageandprocessingofdataunderthedirectionofastoredprogram–

SoftwareComputerhardwaredoesnotstoredatausingthesamesymbolsthathumansdo2024/1/23BUPT-PRF61.2Components2024/1/23BUPT-PRF7CentralProcessingUnit(CPU)Controlunit:directsandmonitorstheoveralloperationofthecomputerKeepstrackofwherethenextinstructionresidesIssuesthesignalsneededtobothreaddatafromandwritedatatootherunitsinthesystemExecutesallinstructionsArithmeticandLogicUnit(ALU):performsallofthecomputations,suchasaddition,subtraction,comparisons,andsoon,thatacomputerprovidesCPUsareconstructedasasinglemicrochip,whichisreferredtoasamicroprocessor2024/1/23BUPT-PRF8Microprocessor2024/1/23BUPT-PRF9MainMemoryUnitStoresdataandinstructionsassequenceofbytesAprogrammustresideinmainmemoryifitistooperateonthecomputerConstructedasRandomAccessMemory(RAM)EverysectionofmemorycanbeaccessedrandomlyasquicklyasanyothersectionDataislostwhenpoweristurnedoffSizeisusuallyspecifiedinbytes(MBorGB)2024/1/23BUPT-PRF10SecondaryStorageUsedaspermanentstorageforprogramsanddataMagnetictape,magneticdisks,andCD-ROMsDirectaccessstoragedevice(DASD):allowsacomputertoreadorwriteanyonefileorprogramindependentofitspositiononthestoragemediumMagneticharddiskconsistsofrigidplattersthatspintogetheronacommonspindleInitially,themostcommonmagneticdiskstoragedevicewastheremovablefloppydisk2024/1/23BUPT-PRF11Input/OutputUnitTheinput/output(I/O)unitprovidesaccesstothecomputer,allowingittoinputandoutputdataItistheinterfacetowhichperipheraldevices(外围设备),suchaskeyboards,console(控制台)screens,andprinters,areattached2024/1/23BUPT-PRF121.ComputerHardware:SummaryHaveyouusedcomputersbefore?When?Forwhatpurpose?Hardware:(describeyourcomputer)CentralProcessingUnit(CPU):ALU,controlMemory:primarystorageSecondarystorage:harddisk,floppydisk,flashingdisk,compactdiskI/Odevices:keyboard,mouse,monitor,projector,printer,scanner…,etc.2024/1/23BUPT-PRF131.3Bits(位)andBytes(字节)ThesmallestandmostbasicdataiteminacomputerisabitOpenorclosedswitch0or1Thegroupingof8bitstoformalargerunitisreferredtoasabyteCanrepresentanyoneof256distinctpatternsThecollectionsofpatternsconsistingof0sand1susedtorepresentletters,singledigits,andothersinglecharactersarecalledcharactercodes(字符码),suchasASCII.2024/1/23BUPT-PRF142.ComputerSoftware&ProgrammingLanguagesSoftware:OperatingSystem(OS,操作系统),Tools,Applicationsoftware,etc.Programming:writinginstructionsinalanguagethatthecomputercanrespondtoandthatotherprogrammerscanunderstandProgramminglanguage:setofinstructionsthatcanbeusedtoconstructaprogram2024/1/23BUPT-PRF152.ComputerSoftware&ComputerLanguagesComputerprogramminglanguagearedesigned(1)tomaketheprogrammingprocesseasier;(2)tocapitalizeonaspecialfeatureofthehardware;(3)tomeetaspecialrequirementofanapplicationDifferentlevelsHighlevellanguageLowlevellanguageAssemblylanguageMachineLanguageThefirstprogramminglanguagetolearnisC,ahighlevellanguage.2024/1/23BUPT-PRF16MachineLanguage

(机器语言)Executableprogram(可执行程序):programthatcanoperateacomputerExecutableprogramsarewrittenwithbinarynumbers,whichisacomputer’sinternallanguage(machinelanguage)Anexampleofasimplemachinelanguageprogramcontainingtwoinstructionsis:01000000000010(+)10000000000011(-)2024/1/23BUPT-PRF17AssemblyLanguage

(汇编语言)Machine

languageismachinedependableandtimeconsumingtowriteAssemblylanguage:

usesthesubstitutionofword-likesymbolsfortheoperation,anddecimalnumbersandlabelsformemoryaddressesLOADfirstADDsecondMULfactorSTOREanswer2024/1/23BUPT-PRF18AssemblyLanguage(continued)2024/1/23BUPT-PRF19Low-andHigh-LevelLanguagesMachineandassemblylanguagesarelow-levellanguagesbecausetheybothuseinstructionsthataredirectlytiedtoonetypeofcomputerAHighlevellanguageusesinstructionsthatresemblehumanlanguages,suchasEnglish,andcanberunonallcomputers.CisaHigh-levellanguageAnswer=(first+second)*factorAFirstBookofANSIC,FourthEdition20Low-andHigh-LevelLanguagesProgramswritteninacomputerlanguagearereferredtoassourceprogramsandsourcecodeWheneachstatementinahigh-levelsourceprogramistranslatedindividuallyandexecutedimmediatelyupontranslation,theprogramminglanguageiscalledaninterpretedlanguageInterpreter:programthattranslateseachstatementinahigh-levelsourceprogramandexecutesitimmediatelyupontranslation2024/1/23BUPT-PRF21Low-andHigh-LevelLanguages(continued)Compiledlanguage:thestatementsinahigh-levelsourceprogramaretranslatedasacompleteunitbeforeanyindividualstatementisexecutedCompilerTheoutputproducedbythecompileriscalledanobjectprogram(目标程序)Linker:combinesadditionalmachinelanguagecodewiththeobjectprogramtocreateafinalexecutableprogram2024/1/23BUPT-PRF22Low-andHigh-LevelLanguages(continued)2024/1/23BUPT-PRF23

CompilationProcess:SummaryCompilationprocessistotranslateahigh-levelprogramminglanguagetolower-levelmachinelanguage(seefigure).Edit(编辑)

asourcefile;Compile(编译)thesourcefile(transferahighlevelprogramminglanguagetothelowerlevelmachinelanguage);Link(链接)compiledobjectfilestoanexecutablefiles;Debug(调试)process:syntaxerrors,logicerrorsTerms:Edit,compile,linkSourcefile(),objectfile,executablefileFilename,sourcefile,rootname,extensionAFirstBookofANSIC,FourthEdition24ProceduralandObject-OrientedLanguagesProcedurallanguage:instructionsareusedtocreateself-containedunits,calledproceduresProcedure:acceptsdataasinputandtransformsitinsomemannertoproduceaspecificresultasoutputAlsocalledfunctionormethodProceduresconformingtostructureguidelinesareknownasstructuredproceduresAFirstBookofANSIC,FourthEdition25ProceduralandObject-OrientedLanguages(continued)Structuredlanguage:high-levelprocedurallanguage(e.g.,C)thatenforcesstructuredproceduresObject-orientedlanguages:languageswithobjectorientationsuchasC++,Java,VisualBasic,andC#AFirstBookofANSIC,FourthEdition26ProceduralandObject-OrientedLanguages(continued)AFirstBookofANSIC,FourthEdition27ApplicationandSystemSoftwareApplicationsoftware:programswrittentoperformparticulartasksrequiredbyusersSystemsoftware:collectionofprogramsthatmustbereadilyavailabletoanycomputersystemtoenablethecomputertooperateAFirstBookofANSIC,FourthEdition28ApplicationandSystemSoftware(continued)Operatingsystem:setofsystemprogramsusedtooperateandcontrolacomputerMultiusersystem:handlesmultipleusersconcurrentlyOperatingsystemsthatpermiteachusertorunmultipleprogramsarereferr