C++复习资料.docx

C++复习资料.docx

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C++复习资料

Fillintheblanksineachofthefollowing:

a.Thecompanythatpopularizedpersonalcomputingwas_

b.Thecomputerthatmadepersonalcomputinglegitimateinbusinessand

industrywasthe__IBMPersonalComputer

c.Computersprocessdataunderthecontrolofsetsofinstructionscalled

computer__programs_______.

d.Thesixkeylogicalunitsofthecomputerarethe_inputunit_,__outputunit,

__memoryunit__,_arithmeticandlogicunit__,_centralprocessingunit__andthe__secondarystorageunit___

e.Thethreeclassesoflanguagesdiscussedinthechapterare_machinelanguages_,

_assemblylanguages_,and__high-levellanguages__.

f.Theprogramsthattranslatehigh-levellanguageprogramsintomachine

languagearecalled___compilers___.

g.Ciswidelyknownasthedevelopmentlanguageofthe_UNIX_operating

system.

h.The_Pascal__languagewasdevelopedbyWirthforteachingstructured

programming.

i.TheDepartmentofDefensedevelopedtheAdalanguagewithacapability

called,whichallowsprogrammerstospecifythatmanyactivitiescan

proceedinparallel.

FillintheblanksineachofthefollowingsentencesabouttheC++environment.

a.C++programsarenormallytypedintoacomputerusinga（n）

program.

b.InaC++system,a（n）__preprocessor__programexecutesbeforethecompiler's

translationphasebegins.

c.The_linker_programcombinestheoutputofthecompilerwithvarious

libraryfunctionstoproduceanexecutableimage.

d.TheprogramtransferstheexecutableimageofaC++programfrom

disktomemory.

Fillintheblanksineachofthefollowingstatements

a.Objectshavethepropertyof__informationhiding_althoughobjectsmayknowhowto

communicatewithoneanotheracrosswell-definedinterfaces,theynormally

arenotallowedtoknowhowotherobjectsareimplemented.

b.C++programmersconcentrateoncreating_classes_,whichcontaindata

membersandthememberfunctionsthatmanipulatethosedatamembersand

provideservicestoclients.

c.Classescanhaverelationshipswithotherclasses.Theserelationshipsarecalled

__associations___.

d.Theprocessofanalyzinganddesigningasystemfromanobject-orientedpoint

ofviewiscalled__object-orientedanalysisanddesign（OOAD）.___.

e.OODalsotakesadvantageof_inheritance__relationships,wherenewclassesof

objectsarederivedbyabsorbingcharacteristicsofexistingclasses,thenadding

uniquecharacteristicsoftheirown.

f.__TheUnifiedModelingLanguage（UML）__isagraphicallanguagethatallowspeoplewhodesignsoftware

systemstouseanindustry-standardnotationtorepresentthem.

g.Thesize,shape,colorandweightofanobjectareconsidered_attributes__ofthe

object.

Whyissomuchattentiontodayfocusedonobject-orientedprogrammingingeneralandC++inparticular

ANS1:

Object-orientedprogrammingenablestheprogrammertobuildreusable

softwarecomponentsthatmodelitemsintherealworld.Buildingsoftwarequickly,correctly,and

economicallyhasbeenanelusivegoalinthesoftwareindustry.Themodular,object-oriented

designandimplementationapproachhasbeenfoundtoincreaseproductivitywhilereducing

developmenttime,errors,andcost.

ANS2:

Inobject-orientedprogramming,thesourcecodeisorganizedinclassesandobjects,which

iseasytobemappingintotheitemsinphysicalworld.Itiseasytodesign,reuseandmaintain

suchkindofsoftwareinlargescalesoftwaredevelopment,whichisfavoredbythesoftware

industry.

【参考教材的答案】面向对象的编程让编程者可以建立可重用的软件组件，这些组件是现实

世界事物的抽象模型。

软件工业的目标是快速、正确、有效率的开发软件。

面向对象的设计

和实现方法模型已经被事实证明是可以提高生产效率和减少开发时间、错误和代价。

【参考讲义的答案】面向对象的编程方法中，以类和对象来组织源代码，可以方便的实现与

现实物理世界事物的映射。

采用这种方法，易于在大型软件开发中进行软件的设计、重用和

维护，因此受到软件行业的支持和采用。

Youareprobablywearingonyourwristoneoftheworld'smostcommontypesofobjectsawatch.Discusshoweachofthefollowingtermsandconceptsappliestothenotionofawatch:

object,attributes,behaviors,class,inheritance（consider,for

example,analarmclock）,abstraction,modeling,messages,encapsulation,interface,

informationhiding,datamembersandmemberfunctions.

可能现在你的手腕上就戴着世界上最普遍的对象类型之一——手表。

论述以下这些术

语和概念如何应用于手表这个概念上：

对象、属性、行为、类、继承（例如，考虑闹钟）、

封装、接口、信息隐藏、数据成员和成员函数。

ANS:

Theentirewatchisanobjectthatiscomposedofmanyotherobjects（suchasthemovingparts,theband,theface,etc.）Watchattributesaretime,color,band,style（digitaloranalog）,etc.Thebehaviorsofthewatchincludesettingthetimeandgettingthetime,Awatchcanbeconsideredaspecifictypeofclock（ascananalarmclock）,Withthatinmind,itispossiblethataclasscalledClockcouldexistfromwhichotherclassessuchaswatchandalarmclockcaninheritthebasicfeaturesintheclock.Thewatchisanabstractionofthemechanicsneededtokeeptrackofthetime.Theuserofthewatchdoesnotneedtoknowthemechanicsofthewatchinordertouseit;theuseronlyneedstoknowthatthewatchkeepsthepropertime.Inthissense,themechanicsofthewatchareencapsulated（hidden）insidethewatch.Theinterfacetothewatch（itsfaceandcontrolsforsettingthetime）allowstheusertosetandgetthetime.Theuserisnotallowedtodirectlytouchtheinternalmechanicsofthewatch.Allinteractionwiththeinternalmechanicsiscontrolledbytheinterfacetothewatch.Thedatamembersstoredinthewatcharehiddeninsidethewatchandthememberfunctions（lookingatthefacetogetthetimeandsettingthetime）providetheinterfacetothedata.

Fillintheblanksineachofthefollowing.

a.EveryC++programbeginsexecutionatthefunction_main_.

b.The__leftbrace（{）_beginsthebodyofeveryfunctionandthe__rightbrace（}）_endsthebodyofeveryfunction.

c.EveryC++statementendswitha（n）__semicolon_______.

d.Theescapesequence\nrepresentsthe__character,whichcausesthecursortopositiontothebeginningofthenextlineonthescreen.

e.The___statementisusedtomakedecisions.

Statewhethereachofthefollowingistrueorfalse.Iffalse,explainwhy.Assumethestatementusingstd:

:

cout;isused.

a.Commentscausethecomputertoprintthetextaftertheb.Theescapesequence\n,whenoutputwithcoutandthestreaminsertionoperator,

causesthecursortopositiontothebeginningofthenextlineonthescreen.

c.Allvariablesmustbedeclaredbeforetheyareused.

d.Allvariablesmustbegivenatypewhentheyaredeclared.

e.C++considersthevariablesnumberandNuMbErtobeidentical.

f.DeclarationscanappearalmostanywhereinthebodyofaC++function.

g.Themodulusoperator（%）canbeusedonlywithintegeroperands.

h.Thearithmeticoperators*,/,%,+andallhavethesamelevelofprecedence.

i.AC++programthatprintsthreelinesofoutputmustcontainthreestatementsusing

coutandthestreaminsertionoperator.

ANS:

a.False.Commentsdonotcauseanyactiontobeperformedwhentheprogramisexecuted.Theyareusedtodocumentprogramsandimprovetheirreadability.

b.True.c.True.d.True.e.False.C++iscasesensitive,sothesevariablesareunique.f.True.g.True.h.False.Theoperators*,/and%havethesameprecedence,andtheoperators+and–havealowerprecedence.i.False.Asinglecoutstatementwithmultiple\nescapesequencescanprintseverallines

WriteasingleC++statementtoaccomplisheachofthefollowing（assumethatusingdeclarationshavenotbeenused）:

a.Declarethevariablesc,thisIsAVariable,q76354andnumbertobeoftypeint.

b.Prompttheusertoenteraninteger.Endyourpromptingmessagewithacolon（:

）

followedbyaspaceandleavethecursorpositionedafterthespace.

c.Readanintegerfromtheuseratthekeyboardandstorethevalueenteredininteger

variableage.

d.Ifthevariablenumberisnotequalto7,print"Thevariablenumberisnotequalto7".

e.Printthemessage"ThisisaC++program"ononeline.

f.Printthemessage"ThisisaC++program"ontwolines.Endthefirstlinewith

C++.

g.Printthemessage"ThisisaC++program"witheachwordonaseparateline.

h.Printthemessage"ThisisaC++program"witheachwordseparatedfromthe

nextbyatab.

ANS;a.intc,thisIsAVariable,q76354,number;

b.std:

:

cout<<"Enteraninteger:

";

c.std:

:

cin>>age;

d.if（number!

=7）

std:

:

cout<<"Thevariablenumberisnotequalto7\n";

e.std:

:

cout<<"ThisisaC++program\n";

f.std:

:

cout<<"ThisisaC++\nprogram\n";

g.std:

:

cout<<"This\nis\na\nC++\nprogram\n";

h.std:

:

cout<<"This\tis\ta\tC++\tprogram\n";

Writeastatement（orcomment）toaccomplisheachofthefollowing（assumethatusingdeclarationshavebeenused）:

a.Statethataprogramcalculatestheproductofthreeintegers.

b.Declarethevariablesx,y,zandresulttobeoftypeint（inseparatestatements）.

c.Prompttheusertoenterthreeintegers.

d.Readthreeintegersfromthekeyboardandstoretheminthevariablesx,yandz.

e.Computetheproductofthethreeintegerscontainedinvariablesx,yandz,and

assigntheresulttothevariableresult.

f.Print"Theproductis"followedbythevalueofthevariableresult.

g.Returnavaluefrommainindicatingthattheprogramterminatedsuccessfully.

ANS:

a.intx;

inty;

intz;

intresult;

c.cout<<"Enterthreeintegers:

";

d.cin>>x>>y>>z;

e.result=x*y*z;

f.cout<<"Theproductis"<

g.return0;

UsingthestatementsyouwroteinExercise,writeacompleteprogramthatcalculatesanddisplaystheproductofthreeintegers.Addcommentstothecodewhereappropriate.[Note:

Youwillneedtowritethenecessaryusingdeclarations.]

ANS:

1if（c<7）;

cout<<"cislessthan7\n";

b.if（c=>7）

cout<<"cisequaltoorgreaterthan7\n";

ANS:

a.Error:

Semicolonaftertherightpa