雨课堂学堂在线学堂云《Java Programming（浙江工业大学）》单元测试考核答案

JavaProgramming第1题Javaisredesignedandimprovedfromthe()language.AAdaBCCPascalDBasic第2题WhichofthefollowingisnotafeatureoftheJavalanguage?APlatformindependenceBObject-orientedCSupportspointertypesDGarbagecollectionmechanism第1题Whichofthefollowingisavalidvariabledeclarationidentifier?()A&ABVariableBC+CD-D第2题WhichofthefollowingisavalidJavaidentifier?()AcatB5booksC+staticD-3.14159第3题WhichofthefollowingisaprimitivedatatypeinJava?AStringBIntegerCintDFloat第4题Whichofthefollowingoperatorsislegal?A&Bc.CifD:=第5题breakstatement()AOnlyinterruptstheinnermostloopBOnlyinterruptstheoutermostloopCWiththehelpoflabels,caninterruptanyouterloopDOnlyinterruptsacertainlayerofloop第6题Whichstatementisusedtoterminatethecurrentloopandexittheouterloop?AbreakBcontinueCexitDreturn第7题WhichofthefollowingcanbeusedasacorrectvariablenameinJava?()A3DBnameCextendsDimplements第8题DefinethestringStrings1="hello";:Whichofthefollowingdescriptionsoftheprogramiscorrect?if(s1=="hello"){System.out.println("s1="hello"");}else{System.out.println("s1!=hello");}AOutputs1!=helloBOutputs1="hello"CGeneratecompilationerrorDCompilescorrectlybutrunswitherrortest第1题WhichofthefollowingdefinitionsofclassMyClassiscorrect?()ApublicclassMyClassextendsClass1,Class2BpublicclassMyClassextendsInterface1implementsClass1CpublicclassMyClassextendsInterface1,Interface2DpublicclassMyClassimplementsInterface1,Interface2第2题Whichofthefollowingisnotallowedasanaccesscontrolmodifierforclassesandclassmembers?()ApublicBprivateCstaticDprotected第3题Whenisaconstructorcalled?()AWhentheclassisdefinedBWhenanobjectiscreatedCWhenanobjectmethodiscalledDWhenanobject'svariableisused第4题ToconstructaninstanceoftheArrayListclass,whichmethodiscorrect?AArrayListmyList=newObject();BArrayListmyList=newArrayList();CmyList=newObject();DmyList=newArrayList();第5题Whichofthefollowingstatementsaboutconstructorsisincorrect?()AJavalanguagestipulatesthattheconstructornamemustbethesameastheclassnameBJavalanguagestipulatesthatconstructorshavenoreturnvalueandarenotdeclaredwithvoidCJavalanguagestipulatesthatconstructorscannotbeoverloadedDJavalanguagestipulatesthatconstructorscanonlybeautomaticallycalledthroughnew第6题Thecorrectdescriptionofthefinalkeywordis().Afinalcanmodifyclasses,methodsandvariablesBfinalcanonlymodifyvariablesCfinalcanonlymodifymethodsDfinalcanonlymodifyclasses第7题Whatistheoutputresultofthefollowingcode?(Understandingofthethiskeyword)classTest{intx;Test(intx){this.x=x;}voidshow(){System.out.println("x="+x);}publicstaticvoidmain(String[]args){Testt1=newTest(10);Testt2=newTest(20);t1.show();t2.show();}}Ax=10x=20Bx=10x=10Cx=20x=20Dx=0x=0第8题RegardingtheuseofthestatickeywordinJava,thecorrectstatementis:AUsedtodeclarethatamethodisstaticBUsedtodeclarethataclassisstaticCUsedtodeclarethatanobjectisstaticDUsedtodeclarethataconstructorisstatic第9题ThepackagethatprovidesJavawiththeabilitytoaccessdatabasesis:Ajava.sqlBjava.awtCjava.langDjava.swingtest第1题Whichofthefollowingstatementsaboutinheritanceiscorrect?()AInJava,aclasscaninheritfromoneclassandoneinterfaceatthesametimeBInJava,aninterfacecaninheritfrommultipleinterfacesatthesametimeCAsubclasscanonlyinheritthepublicmethodsandattributesofitsparentclassDAsubclasscanonlyinheritthemethodsofitsparentclass,nottheattributes第2题Giventhefollowingcode,howtomakethemembervariablembedirectlyaccessedbythemethodfun()?classTest{privateintm;publicstaticvoidfun(){}}AChangeprivateintmtoprotectedintmBChangeprivateintmtopublicintmCChangeprivateintmtostaticintmDChangeprivateintmtointm第3题WhichofthefollowingdescriptionsaboutthesuperkeywordinJavaiscorrect?()AsupercanbeusedtoaccessmembersofthesubclassBsuperisusedtoaccesstheconstructoroftheparentclassCsupercannotaccesstheprivatemembersoftheparentclassDsupercanreplacethistocallmembersofthecurrentclass第4题Ifthemethodmymethod()inasubclassoverridesthemethodmymethod()initsparentclass,andtheparentclassmethodisdefinedasfollows:voidmymethod(inta),whichofthefollowingdefinitionsofthesubclassmethodisillegal?()Apublicvoidmymethod(inta)Bprotectedvoidmymethod(inta)Cprivatevoidmymethod(inta)Dvoidmymethod(inta)第5题Whichofthefollowingisacorrectdescriptionofmethodoverloading?()AThereturnvaluetypesofoverloadedmethodsmustbedifferentBTheparameternamesofoverloadedmethodsmustbedifferentCThemodifiersofoverloadedmethodsmustbedifferentDTheparametersofoverloadedmethodsmustbedifferent(parametertype,numberofparameters,ororderofparametertypes)第6题Whichkeywordcanbeusedtopreventamethodfrombeingoverriddenbyasubclass?()AabstractBstaticCfinalDvolatile第7题Whichofthefollowingstatementsaboutabstractclassesandinterfacesiscorrect?()AAnabstractclasscanbeusedtodefineaninterfaceBAllmethodsinanabstractclassareconcrete(withimplementations)CAnabstractclasscanbeanimplementationofaninterfaceDTheabstractkeywordisrequiredwhendefininganabstractclass第8题InJava,whichinterfaceistheparentinterfaceofallcollectionclasses?()ACollectionBSetCListDIterable第9题Giventhefollowinginterfacedefinition:publicinterfaceA{StringDEFAULT_GREETING="HelloWorld";publicvoidmethod1();}Whichofthefollowingclassorinterfacedefinitionsiscorrect?()AabstractclassBimplementsA{abstractprotectedvoidmethod1();}BpublicinterfaceBextendsA{}CpublicinterfaceBimplementsA{}DclassBextendsA{publicvoidmethod1(){return;}}第10题ClassAderivesasubclassB,andBderivesasubclassC.Forthefollowing3linesofJavacode,whichstatementiscorrect?()Aa1=newA();Aa2=newB();Aa3=newC();ALines1,2,and3allcompilesuccessfully,butlines2and3throwerrorsduringruntimeBOnlyline1compilessuccessfullyCLines1and2compilesuccessfully,butline3failstocompileDThedeclarationsinlines1,2,and3areallcorrecttest第1题Whichofthefollowingstatementsaboutarraysiscorrect?()AThearraytypebelongstoprimitivetypesBAfteranarrayiscreated,itslengthcanbechangedCArrayelementscannotbeobjectsDOnceanarrayiscreated,itslengthcannotbemodified第2题Whichofthefollowingarraydeclarationsisincorrect?()Aint[]arry=newint[100];Bint[3]arry={1,2,3};Cint[]arry=newint[]{1,2,3};Dint[][]arry=newint[3][];第3题Whichofthefollowingarraydefinitionsfailstocompile?()Aint[]scores={80,85,87};Bint[][]scores={82,87,96},{92,83,45};CStringcats[]={"Fluffy","Spot","Zeus"};DIntegerresults[]={1,2,newInteger(3)};第4题InJava,whichmethodisusedtocomparewhetherthecontentsoftwostringsareequal?()A==BcompareTo()Cequals()Dcompare()第5题Thefollowingcodeisusedtocalculatethelengthofastring.Whichcodeshouldbefilledintheblank?()publicclassMain{publicstaticvoidmain(String[]args){Stringstr="HelloWorld!";intlength=0;//<insertcode>System.out.println("Length="+length);}}Alength=str.length();Blength=str.charAt(str.length());Clength=str.size();Dlength=str.length()-1;第6题Whichofthefollowingdefinitionsofatwo-dimensionalarrayiscorrect?()Aint[][]a=newint[][]Bint[][]a=newint[][5]Cinta[][]=newint[3][]Dinta[2][3]={{1,2,3},{4,5,6}}test第1题Regardingtheimportjava.utilpackage,whichofthefollowingstatementsisincorrect?()ATheVectorclassbelongstothejava.utilpackageBTheVectorclassislocatedinthe…/java/util/directoryCTheVectorclassisstoredinthejava.utilfileDTheVectorclassisaproductofSunMicrosystems第2题WhichpackageisimportedbydefaultbytheJavaVirtualMachine()?()Ajava.appletBjava.langCjava.ioDjava.awttest第1题Whichofthefollowingstatementsaboutexceptionsiscorrect?()AOnceanexceptionoccurs,theprogramexecutionterminatesimmediatelyBIfamethoddeclaresthatitwillthrowacertainexception,itmustactuallythrowthatexceptionCMatchingexceptionsinthecatchclauseisanexactmatchDMethodsthatmaythrowsystemexceptionsdonotneedtodeclaretheexceptions第2题WhichofthefollowingstatementsaboutJavaexceptionhandlingiscorrect?()AExceptionclassesarederivedfromtheThrowableclassBWhencatchingexceptions,multiplecatchblockscanbeused,buttherecanonlybeonefinallyblockCthrowisusedtodeclareexceptionsDthrowsisusedtothrowexceptions第3题Regardingtheexceptionhandlingstatementtry…catch…finally,whichofthefollowingstatementsiscorrect?()AtrycanbeusedaloneBIftherearemultiplecatchstatements,eachcatchthatmeetstheconditionswillbeexecutedonceCWhenanexceptionoccursintheprogram,afterfindingthecatchthatmeetstheconditions,thesubsequentcatchblockswillnotbeexecutedDOncethecatchblockisexecutedintheprogram,thefinallyblockwillnotbeexecuted第4题InJava,whichofthefollowingisthecorrectorderofexceptionhandlingkeywords?()Atry→catch→finallyBcatch→finally→tryCfinally→catch→tryDtry→finally→catch第5题Whattypeofexceptionoccursafterthefollowingcoderuns?()publicclassTest{publicstaticvoidmain(String[]args){for(inti=0;i<2;i++){System.out.println(args[i]);}}}Runningcommand:javaTesthelloAFirstoutputhello,thenanexceptionoccurs,andtheexceptiontypeisArithmeticExceptionBAnexceptionoccurs,andtheexceptiontypeisIOExceptionCFirstoutputhello,thenanexceptionoccurs,andtheexceptiontypeisArrayIndexOutOfBoundsExceptionDTheprogramoutputstheinformationhellonormallytest第1题Whichofthefollowingstreamsbelongstothecharacterstream?()AInputStreamBFileInputStreamCDataInputStreamDFileReader第2题RegardingJavainputandoutputstreams,whichofthefollowingstatementsiscorrect?()ABothFileReaderandFileInputStreamreaddatabybytesBBothFileReaderandFileInputStreamreaddatabycharactersCFileReaderreadsdatabybytes,whileFileInputStreamreadsdatabycharactersDFileReaderreadsdatabycharacters,whileFileInputStreamreadsdatabybytes第3题WhenreadingthecharacterfileEmployee.dat,whichclassusesthisfileasaparameter?()ABufferedReaderBDataInputStreamCDataOutputStreamDFileInputStream第4题Whichofthefollowingfilereadingandwritingclassessupportsthe"encodingmethod"parameterinitsconstructor?()ABufferedInputStreamBBufferedOutputStreamCInputStreamReaderDFileOutputStream第5题Supposethecontentofthefilec:/a.txtis"abcd".Whatistheresultofexecutingthefollowingcode?()importjava.io.*;publicclassTest{publicstaticvoidmain(Stringargs[])throwsIOException{FileInputStreamfis=newFileInputStream("c:/a.txt");intdata=fis.read();System.out.println(data);fis.close();}}A97BaC-1DCompilationerror第6题Whichofthefollowingfilereadingandwritingclassessupportsthe"encodingmethod"parameterinitsconstructor?()ABufferedInputStreamBBufferedOutputStreamCInputStreamReaderDFileOutputStreamtest第1题Afteracontainerisresized,thecomponentsinthecontainerofwhichlayoutmanagerdonotchangesizewiththecontainer'ssize?()AFlowLayoutBBoxLayoutCBorderLayoutDGridLayout第2题WhichofthefollowingJavacomponentsisacontainercomponent?()AListboxJListBDrop-downlistboxJComboBoxCPanelJPanelDCommandmenuitemJMenuItem第3题Acomponentchangessizehorizontallybutremainsthesamesizevertically.Whichpositionshoulditbeplacedin?()ANorthorSouthpositionofBorderLayoutBEastorWestpositionofBorderLayoutCCenterpositionofBorderLayoutDInGridLayout第4题RegardingJava'seventhandlingmechanism,whichofthefollowingstatementsiscorrect?()AEverycomponentcantriggeranytypeofeventBTheeventhandlingmechanismhasthreeelements:eventsource,listener,andeventhandlinginterfaceCAlistenerdoesnotneedtoimplementallmethodsintheinterface;itcanonlyimplementoneorseveralrequiredmethodsDForeventsgeneratedbyanycomponent,aneventadaptercanbedefinedtohandlethem第5题Whichofthefollowingdescriptionsaboutgraphicaluserinterface()elementsisincorrect?()AThejavax.swingpackagecontainsvariouscomponentsofGUIBThecontainerclass(Container)isasubclassofthecomponentclass(Component)CComponentscanbeaddedtoacontainer,butcontainerscannotbeaddedtoacontainerDThearrangementofcomponentsinacontainerisdeterminedbythelayoutmanagerclasstest第1题WhichofthefollowingstatementsaboutJavathreadsiscorrect?()AAthreadcanonlyrunonceBThestateofathreadismanagedbytheoperatingsystemCAthreadcanbestartedbycallingthestart()methodDTherun()methodofathreadmustbecalledinthemainthread第2题Regardingdaemonthreads(backgroundthreads),whichofthefollowingstatementsisincorrect?()AThreadscreatedinadaemonthreadmustalsobedaemonthreadsBDaemonthreadswillautomaticallyterminateafteralluserthreadsfinishrunningCDaemonthreadsareusuallyusedtoprovideservicesforuserthreadsDThemethodtosetathreadtasadaemonthreadis:t.setDaemon(true);第3题Whichofthefollowingstatementsaboutthreadsisincorrect?()AThethreadbody(dataandexecutioninstructionsequence)canbeimplementedbyinheritingtheThreadclassorimplementingtheRunnableinterfaceBThreadsarescheduledforexecutionbypriority;threadswithhigherprioritywillbeexecutedfirstCThepurposeofmulti-threadsynchronizationistoallowmultiplethreadstoworkconcurrentlyinacoordinatedmannerDWhenmultiplethreadsexecuteconcurrently,therelativeexecutionorderofthreadsisdeterminedbytheorderinwhichthethreadsarestarted第4题WhichofthefollowingstatementsaboutthreadsinJavaisincorrect?()ACallingthejoin()methodmaythrowanInterruptedExceptionBThesleep()methodisastaticmethodoftheThreadclassCCallingthesleep()methodoftheThreadclasscanterminateathreadobjectDThecodeexecutedbyathreadafteritisstartedisplacedinitsrunmethod第5题Iftisathreadobject,whichofthefollowingstatementsisincorrect?()At.start()willstartthreadttoparticipateinthreadschedulingBt.sleep(1)willmakethreadtsleepfor1secondCThet.run()statementwilldirectlyruntherun()methodinsteadofstartingthreadttoparticipateinschedulingDAfterthethreadisstarted,oncetherun()methodfinishesrunning,threadtwillalsodie第6题ThefollowingcodesnippetusestheThreadcl