JAVA題庫(kù)-格林模擬試題二（上）

1、姓名：_ 班級(jí)：_ 學(xué)號(hào)：_-密-封 -線- java題庫(kù):格林模擬試題二（上）考試時(shí)間：120分鐘 考試總分：100分題號(hào)一二三四五總分分?jǐn)?shù)遵守考場(chǎng)紀(jì)律，維護(hù)知識(shí)尊嚴(yán)，杜絕違紀(jì)行為，確?？荚嚱Y(jié)果公正。question1) whatwillhappenwhenyouattempttocompileandrunthiscode? abstractclassbaseabstractpublicvoidmyfunc();publicvoidanother()system.out.println(“anothermethod”);publicclassabsextendsbasepublicstati

2、cvoidmain(stringargv)absa=newabs();a.amethod();publicvoidmyfunc()system.out.println(“myfunc”);publicvoidamethod()myfunc(); 1)thecodewillcompileandrun,printingoutthewords”myfunc” 2)thecompilerwillcomplainthatthebaseclasshasnonabstractmethods 3)thecodewillcompilebutcomplainatruntimethatthebaseclasshas

3、nonabstractmethods 4)thecompilerwillcomplainthatthemethodmyfuncinthebaseclasshasnobody,nobodyatalltoloooveit question2) whatwillhappenwhenyouattempttocompileandrunthiscode? publicclassmymainpublicstaticvoidmain(stringargv)system.out.println(“hellocruelworld”); 1)thecompilerwillcomplainthatmainisares

4、ervedwordandcannotbeusedforaclass 2)thecodewillcompileandwhenrunwillprintout”hellocruelworld” 3)thecodewillcompilebutwillcomplainatruntimethatnoconstructorisdefined 4)thecodewillcompilebutwillcomplainatruntimethatmainisnotcorrectlydefined question3) whichofthefollowingarejavamodifiers? 1)public 2)pr

5、ivate 3)friendly 4)transient 5)vagrant question4) whatwillhappenwhenyouattempttocompileandrunthiscode? classbaseabstractpublicvoidmyfunc();publicvoidanother()system.out.println(“anothermethod”);publicclassabsextendsbasepublicstaticvoidmain(stringargv)absa=newabs();a.amethod();publicvoidmyfunc()syste

6、m.out.println(“myfunc”);publicvoidamethod()myfunc(); 1)thecodewillcompileandrun,printingoutthewords”myfunc” 2)thecompilerwillcomplainthatthebaseclassisnotdeclaredasabstract. 3)thecodewillcompilebutcomplainatruntimethatthebaseclasshasnonabstractmethods 4)thecompilerwillcomplainthatthemethodmyfuncinth

7、ebaseclasshasnobody,nobodyatalltoloooveit question5) whymightyoudefineamethodasnative? 1)togettoaccesshardwarethatjavadoesnotknowabout 2)todefineanewdatatypesuchasanunsignedinteger 3)towriteoptimisedcodeforperformanceinalanguagesuchasc/c+ 4)toovercomethelimitationoftheprivatescopeofamethod question6

8、) whatwillhappenwhenyouattempttocompileandrunthiscode? classbasepublicfinalvoidamethod()system.out.println(“amethod”);publicclassfinextendsbasepublicstaticvoidmain(stringargv)baseb=newbase();b.amethod(); 1)compiletimeerrorindicatingthataclasswithanyfinalmethodsmustbedeclaredfinalitself 2)compiletime

9、errorindicatingthatyoucannotinheritfromaclasswithfinalmethods 3)runtimeerrorindicatingthatbaseisnotdefinedasfinal 4)successincompilationandoutputof”amethod”atruntime. question7) whatwillhappenwhenyouattempttocompileandrunthiscode? publicclassmodpublicstaticvoidmain(stringargv)publicstaticnativevoida

10、method(); 1)erroratcompilation:nativemethodcannotbestatic 2)erroratcompilationnativemethodmustreturnvalue 3)compilationbuterroratruntimeunlessyouhavemadecodecontainingnativeamethodavailable 4)compilationandexecutionwithouterror question8) whatwillhappenwhenyouattempttocompileandrunthiscode? privatec

11、lassbasepublicclassvistransientintival;publicstaticvoidmain(stringelephant) 1)compiletimeerror:basecannotbeprivate 2)compiletimeerrorindicatingthatanintegercannotbetransient 3)compiletimeerrortransientnotadatatype 4)compiletimeerrormalformedmainmethod question9) whathappenswhenyouattempttocompileand

12、runthesetwofilesinthesamedirectory? /filep1.javapackagemypackage;classp1voidafancymethod()system.out.println(“whatafancymethod”);/filep2.javapublicclassp2extendsp1publicstaticvoidmain(stringargv)p2p2=newp2();p2.afancymethod(); 1)bothcompileandp2outputs”whatafancymethod”whenrun 2)neitherwillcompile 3

13、)bothcompilebutp2hasanerroratruntime 4)p1compilescleanlybutp2hasanerroratcompiletime question10) youwanttofindoutthevalueofthelastelementofanarray.youwritethefollowingcode.whatwillhappenwhenyoucompileandrunit.? publicclassmyarpublicstaticvoidmain(stringargv)inti=newint;system.out.println(i); 1)anerr

14、oratcompiletime 2)anerroratruntime 3)thevalue0willbeoutput 4)thestring”null”willbeoutput question11) youwanttoloopthroughanarrayandstopwhenyoucometothelastelement.beingagoodjavaprogrammerandforgettingeverythingyoueverknewaboutc/c+youknowthatarrayscontaininformationabouttheirsize.whichofthefollowingc

15、anyouuse? 1)myarray.length(); 2)myarray.length; 3)myarray.size 4)myarray.size(); question12) whatbestdescribestheappearanceofanapplicationwiththefollowingcode? importjava.awt.*;publicclassflowapextendsframepublicstaticvoidmain(stringargv)flowapfa=newflowap();fa.setsize(400,300);fa.setvisible(true);f

16、lowap()add(newbutton(“one”);add(newbutton(“two”);add(newbutton(“three”);add(newbutton(“four”);/endofconstructor/endofapplication 1)aframewithbuttonsmarkedonetofourplacedoneachedge. 2)aframewithbuutonsmarkedonetofourrunningfromthetoptobottom 3)aframewithonelargebuttonmarkedfourinthecentre 4)anerrorat

17、runtimeindicatingyouhavenotsetalayoutmanager question13) howdoyouindicatewhereacomponentwillbepositionedusingflowlayout? 1)north,south,east,west 2)assignarow/columngridreference 3)passax/ypercentageparametertotheaddmethod 4)donothing,theflowlayoutwillpositionthecomponent question14) howdoyouchangeth

18、ecurrentlayoutmanagerforacontainer 1)usethesetlayoutmethod 2)oncecreatedyoucannotchangethecurrentlayoutmanagerofacomponent 3)usethesetlayoutmanagermethod 4)usetheupdatelayoutmethod question15) whichofthefollowingarefieldsofthegridbagconstraintsclass? 1)ipadx 2)fill 3)insets 4)width question16) whatm

19、ostcloselymatchestheappearancewhenthiscoderuns? importjava.awt.*;publicclasscomplayextendsframepublicstaticvoidmain(stringargv)complaycl=newcomplay();complay()panelp=newpanel();p.setbackground(color.pink);p.add(newbutton(“one”);p.add(l3)thebuttonswillnotbedisplayed 4)onlybuttonthreewillshowoccupying

20、alloftheframe question17) whichstatementsarecorrectabouttheanchorfield? 1)itisafieldofthegridbaglayoutmanagerforcontrollingcomponentplacement 2)itisafieldofthegridbagconstraintsclassforcontrollingcomponentplacement 3)avalidsettingfortheanchorfieldisgridbagconstraints.north 4)theanchorfieldcontrolsth

21、eheightofcomponentsaddedtoacontainer question18) whatwillhappenwhenyouattempttocompileandrunthefollowingcode? publicclassbgroundextendsthreadpublicstaticvoidmain(stringargv)bgroundb=newbground();b.run();publicvoidstart()for(inti=0;i10;i+)system.out.println(“valueofi=“+i); 1)acompiletimeerrorindicati

22、ngthatnorunmethodisdefinedforthethreadclass 2)aruntimeerrorindicatingthatnorunmethodisdefinedforthethreadclass 3)cleancompileandatruntimethevalues0to9areprintedout 4)cleancompilebutnooutputatruntime question19) isthefollowingstatementtrueorfalse? whenusingthegridbaglayoutmanager,eachnewcomponentrequ

23、iresanewinstanceofthegridbagconstraintsclass. 1)true 2)false question20) whichmostcloselymatchesadescriptionofajavamap? 1)avectorofarraysfora2dgeographicrepresentation 2)aclassforcontaininguniquearrayelements 3)aclassforcontaininguniquevectorelements 4)aninterfacethatensuresthatimplementingclassesca

24、nnotcontainduplicatekeys question21) howdoesthesetcollectiondealwithduplicateelements? 1)anexceptionisthrownifyouattempttoaddanelementwithaduplicatevalue 2)theaddmethodreturnsfalseifyouattempttoaddanelementwithaduplicatevalue 3)asetmaycontainelementsthatreturnduplicatevaluesfromacalltotheequalsmetho

25、d 4)duplicatevalueswillcauseanerroratcompiletime question22) whatcancauseathreadtostopexecuting? 1)theprogramexitsviaacalltosystem.exit(0); 2)anotherthreadisgivenahigherpriority 3)acalltothethreadsstopmethod. 4)acalltothehaltmethodofthethreadclassquestion23) foraclassdefinedinsideamethod,whatrulegov

26、ernsaccesstothevariablesoftheenclosingmethod? 1)theclasscanaccessanyvariable 2)theclasscanonlyaccessstaticvariables 3)theclasscanonlyaccesstransientvariables 4)theclasscanonlyaccessfinalvariables question24) underwhatcircumstancesmightyouusetheyieldmethodofthethreadclass 1)tocallfromthecurrentlyrunn

27、ingthreadtoallowanotherthreadofthesameorhigherprioritytorun 2)tocallonawaitingthreadtoallowittorun 3)toallowathreadofhigherprioritytorun 4)tocallfromthecurrentlyrunningthreadwithaparameterdesignatingwhichthreadshouldbeallowedtorun question25) whatwillhappenwhenyouattempttocompileandrunthefollowingco

28、de publicclasshopepublicstaticvoidmain(stringargv)hopeh=newhope();protectedhope()for(inti=0;i10;i+)system.out.println(i); 1)compilationerror:constructorscannotbedeclaredprotected 2)runtimeerror:constructorscannotbedeclaredprotected 3)compilationandrunningwithoutput0to10 4)compilationandrunningwithou

29、tput0to9 question26) whatwillhappenwhenyouattempttocompileandrunthefollowingcode publicclassmyswitchpublicstaticvoidmain(stringargv)myswitchms=newmyswitch();ms.amethod();publicvoidamethod()intk=10;switch(k)default:/putthedefaultatthebottom,notheresystem.out.println(“thisisthedefaultoutput”);break;ca

30、se10:system.out.println(“ten”);case20:system.out.println(“twenty”);break; 1)noneoftheseoptions 2)compiletimeerrortargetofswitchmustbeanintegraltype 3)compileandrunwithoutput”thisisthedefaultoutput” 4)compileandrunwithoutputofthesingleline”ten” question22) whatcancauseathreadtostopexecuting? 1)thepro

31、gramexitsviaacalltosystem.exit(0); 2)anotherthreadisgivenahigherpriority 3)acalltothethreadsstopmethod. 4)acalltothehaltmethodofthethreadclassquestion23) foraclassdefinedinsideamethod,whatrulegovernsaccesstothevariablesoftheenclosingmethod? 1)theclasscanaccessanyvariable 2)theclasscanonlyaccessstati

32、cvariables 3)theclasscanonlyaccesstransientvariables 4)theclasscanonlyaccessfinalvariables question24) underwhatcircumstancesmightyouusetheyieldmethodofthethreadclass 1)tocallfromthecurrentlyrunningthreadtoallowanotherthreadofthesameorhigherprioritytorun 2)tocallonawaitingthreadtoallowittorun 3)toal

33、lowathreadofhigherprioritytorun 4)tocallfromthecurrentlyrunningthreadwithaparameterdesignatingwhichthreadshouldbeallowedtorun question25) whatwillhappenwhenyouattempttocompileandrunthefollowingcode publicclasshopepublicstaticvoidmain(stringargv)hopeh=newhope();protectedhope()for(inti=0;i10;i+)system

34、.out.println(i); 1)compilationerror:constructorscannotbedeclaredprotected 2)runtimeerror:constructorscannotbedeclaredprotected 3)compilationandrunningwithoutput0to10 4)compilationandrunningwithoutput0to9 question26) whatwillhappenwhenyouattempttocompileandrunthefollowingcode publicclassmyswitchpubli

35、cstaticvoidmain(stringargv)myswitchms=newmyswitch();ms.amethod();publicvoidamethod()intk=10;switch(k)default:/putthedefaultatthebottom,notheresystem.out.println(“thisisthedefaultoutput”);break;case10:system.out.println(“ten”);case20:system.out.println(“twenty”);break; 1)noneoftheseoptions 2)compiletimeerrortargetofswitchmustbeanintegraltype 3)compileandrunwithoutput”thisisthedefaultoutput” 4)compileandrunwithoutputofthesingleline”ten” question27) whichofthefollowingisthecorrectsyntaxforsuggestingthatthejvmperformsgarbagecollection 1)system.free(); 2)system.setgarbagecollection(); 3)syste