JAVA题库-格林模拟试题三（上）

1、姓名：_ 班级：_ 学号：_-密-封 -线- java题库:格林模拟试题三（上）考试时间：120分钟 考试总分：100分题号一二三四五总分分数遵守考场纪律，维护知识尊严，杜绝违纪行为，确保考试结果公正。questions question1) whichofthefollowingarelegalstatements? 1)floatf=1/3; 2)inti=1/3; 3)floatf=1.01; 4)doubled=999d; question2) whichofthefollowingarejavakeywords? 1)null 2)new 3)instanceof 4)wend qu

2、estion3) whichofthefollowingarevalidstatements? 1)system.out.println(1+1); 2)inti=2+2; 3)strings=“on”+one; 4)byteb=255; question4) whichofthefollowingstatementsaretrue? 1)thegarbagecollectionalgorithminjavaisvendorimplemented 2)thesizeofprimitivesisplatformdependent 3)thedefaulttypeforanumericallite

3、ralwithdecimalcomponentisafloat. 4)youcanmodifythevalueinaninstanceoftheintegerclasswiththesetvaluemethod question5) whichofthefollowingaretruestatements? 1)i/oinjavacanonlybeperformedusingthelistenerclasses 2)therandomaccessfileclassallowsyoutomovedirectlytoanypointafile. 3)thecreationofanamedinsta

4、nceofthefileclasscreatesamatchingfileintheunderlyingoperatingsystemonlywhentheclosemethodiscalled. 4)thecharacteristicsofaninstanceofthefileclasssuchasthedirectoryseparator,dependonthecurrentunderlyingoperatingsystem question6) whichofthefollowingstatementsaretrue? 1)theinstanceofoperatorcanbeusedto

5、determineifareferenceisaninstanceofaclass,butnotaninterface. 2)theinstanceofoperatorcanbeusedtodetermineifareferenceisaninstanceofaparticularprimitivewrapperclass 3)theinstanceofoperatorwillonlydetermineifareferenceisaninstanceofaclassimmediatelyaboveinthehierarchybutnofurtheruptheinheritancechain 4

6、)theinstanceofoperatorcanbeusedtodetermineifonereferenceisofthesameclassasanotherreferencethus question7) whichofthefollowingstatementsaretrue? 1)aninterfacecanonlycontainmethodandnotvariables 2)interfacescannothaveconstructors 3)aclassmayextendonlyoneotherclassandimplementonlyoneinterface 4)interfa

7、cesarethejavaapproachtoaddressingitslackofmultipleinheritance,butrequireimplementingclassestocreatethefunctionalityoftheinterfaces. question8) whichofthefollowingarevalidstatements 1)publicclassmycalcextendsmath 2)math.max(s); 3)math.round(9.99,1); 4)math.mod(4,10); question9) whichofthefollowingare

8、methodsoftherunnableinterface 1)run 2)start 3)yield 4)stop转 question10) whichofthefollowingstatementsaretrue? 1)abytecanrepresentbetween-128to127 2)abytecanrepresentbetween-127to128 3)abytecanrepresentbetween-256to256 4)acharcanrepresentbetween-2x2pow162x2pow16-1 question11) whatwillhappenwhenyouatt

9、empttocompileandrunthefollowingcode classbase publicvoidbase() system.out.println(“base”); publicclassinextendsbase publicstaticvoidmain(stringargv) ini=newin(); 1)compiletimeerrorbaseisakeyword 2)compilationandnooutputatruntime 3)outputofbase 4)runtimeerrorbasehasnovalidconstructor question12) youh

10、aveapublicclasscalledmyclasswiththemainmethoddefinedasfollows publicstaticvoidmain(stringparm) system.out.println(parm0); ifyouattempttocompiletheclassandruntheprogramasfollows javamyclasshello whatwillhappen? 1)compiletimeerror,mainisnotcorrectlydefined 2)runtimeerror,mainisnotcorrectlydefined 3)co

11、mpilationandoutputofjava 4)compilationandoutputofhello question13) whichofthefollowingstatementsaretrue? 1)ifaclasshasanyabstractmethodsitmustbedeclaredabstractitself. 2)allmethodsinanabstractclassmustbedeclaredasabstract 3)whenappliedtoaclass,thefinalmodifiermeansitcannotbesub-classed 4)transientan

12、dvolatilearejavamodifiers question14) whichofthefollowingarevalidmethods? 1)publicstaticnativevoidamethod() 2)publicstaticvoidamethod() 3)privateprotectedvoidamethod() 4)staticnativevoidamethod(); question15) whichofthefollowingstatementsaretrue? 1)constructorscannothaveavisibilitymodifier 2)constru

13、ctorscanbemarkedpublicandprotected,butnotprivate 3)constructorscanonlyhaveaprimitivereturntype 4)constructorsarenotinheritedquestion16) whatwillhappenwhenyouattempttocompileandrunthefollowingclass? classbase base(inti) system.out.println(“base”); classsevernextendsbase publicstaticvoidmain(stringarg

14、v) severns=newsevern(); voidsevern() system.out.println(“severn”); 1)compilationandoutputofthestring”severn”atruntime 2)compiletimeerror 3)compilationandnooutputatruntime 4)compilationandoutputofthestring”base” question17) whichofthefollowingstatementsaretrue? 1)staticmethodsdonothaveaccesstotheimpl

15、icitvariablecalledthis 2)astaticmethodmaybecalledwithoutcreatinganinstanceofitsclass 3)astaticmethodmaynotbeoverridentobenon-static 4)astaticmethodmaynotbeoverloaded question18) whichofthefollowingwillcompilewithouterror? 1) charc=1; system.out.println(c1); 2) integeri=integer(“1”); system.out.print

16、ln(i1); 3) inti=1; system.out.println(i1); 4) inti=1; system.out.println(i1); question19) whichofthefollowingaretrue? 1)acomponentmayhaveonlyoneeventlistenerattachedatatime 2)aneventlistenermayberemovedfromacomponent 3)theactionlistenerinterfacehasnocorrespondingadapterclass 4)theprocessingofanevent

17、listenerrequiresatry/catchblockquestion20) whichofthefollowingarejavakeywords? 1)sizeof 2)main 3)transient 4)volatile question21) whichofthefollowingstatementsaretrue? 1)thedefaultconstructorhasareturntypeofvoid 2)thedefaultconstructortakesaparameterofvoid 3)thedefaultconstructortakesnoparameters 4)

18、thedefaultconstructorisnotcreatediftheclasshasanyconstructorsofitsown. question22) whichofthefollowingstatementsaretrue? 1)allofthevariablesinaninterfaceareimplicitlystatic 2)allofthevariablesinaninterfaceareimplicitlyfinal 3)allofthemethodsinaninterfaceareimplicitlyabstract 4)amethodinaninterfaceca

19、naccessclasslevelvariables question23) whichofthefollowingstatementsaretrue? 1)thestringclassisimplementedasachararray,elementsareaddressedusinglwhichofthefollowingstatementsaretrue? 1)amethodinaninterfacemustnothaveabody 2)aclassmayextendoneotherclassplusatmostoneinterface 3)aclassmayextendsatmosto

20、neotherclassplusimplementmanyinterfaces 4)anclassaccessesaninterfaceviathekeyworduses question25) whichofthefollowingstatementsaretrue? 1)thefollowingstatementwillproducearesultof1.system.out.println(-12); 2)performinganunsignedleftshift()onanegativenumberwillalwaysproduceanegativenumberresult 3)the

21、followingstatementwillproducearesultofzero,system.out.println(11); 4)allthejavaintegraltypesaresignednumbers question26) whichofthefollowingstatementsaretrue? 1)theelementsinajavaarraycanonlybeofprimitivetypes,notobjects 2)arrayselementsareinitializedtodefaultvalueswherevertheyarecreatedusingthekewo

22、rdnew 3)anarraymaybedynamicallyresizedusingthesetsizemethod 4)youcanfindoutthesizeofanarrayusingthesizemethod question27) giventhefollowingclass publicclassombersley publicstaticvoidmain(stringargv) booleanb1=true; if(b1=true)|place(true) system.out.println(“hellocrowle”); publicstaticbooleanplace(b

23、ooleanlocation) if(location=true) system.out.println(“borcetshire”); system.out.println(“powick”); returntrue; whatwillhappenwhenyouattempttocompileandrunit? 1)compiletimeerror 2)outputof”hellocrowle” 3)outputofborcetshireandpowickfollowedby”hellocrowle” 4)nooutput question28) youaregivenaclasshiera

24、rchywithaninstanceoftheclassdog.theclassdogisachildofmammalandtheclassmammalisachildoftheclassvertebrate.theclassvertebratehasamethodcalledmovewhichprintsoutthestring”move”.theclassmammaloverridesthismethodandprintsoutthestring”walks”.theclassdogoverridesthismethodandprintsoutthestring”walksonpaws”.givenaninstanceoftheclassdog,.howcanyouaccesstheance