SCJP Mock Exam 2.docx

SCJP Mock Exam 2.docx

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SCJPMockExam2

Question1）

Whichofthefollowingarelegalstatements?

1）floatf=1/3;

2）inti=1/3;

3）floatf=1.01;

4）doubled=999d;

AnswertoQuestion1）

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Question2）

WhichofthefollowingareJavakeywords?

1）NULL

2）new

3）instanceOf

4）wend

AnswertoQuestion2）

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Question3）

Whichofthefollowingarevalidstatements?

1）System.out.println（1+1）;

2）inti=2+'2';

3）c

4）byteb=255;

AnswertoQuestion3）

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Question4）

Whichofthefollowingstatementsaretrue?

1）ThegarbagecollectionalgorithminJavaisvendorimplemented

2）Thesizeofprimitivesisplatformdependent

3）Thedefaulttypeforanumericalliteralwithdecimalcomponentisafloat.

4）YoucanmodifythevalueinanInstanceoftheIntegerclasswiththesetValuemethod

AnswertoQuestion4）

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Question5）

Whichofthefollowingaretruestatements?

1）I/OinJavacanonlybeperformedusingtheListenerclasses

2）TheRandomAccessFileclassallowsyoutomovedirectlytoanypointafile.

3）ThecreationofanamedinstanceoftheFileclasscreatesamatchingfileintheunderlyingoperatingsystemonlywhentheclosemethodiscalled.

4）ThecharacteristicsofaninstanceoftheFileclasssuchasthedirectoryseparator,dependonthecurrentunderlyingoperatingsystem

AnswertoQuestion5）

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Question6）.

Whichofthefollowingstatementsaretrue?

1）Theinstanceofoperatorcanbeusedtodetermineifareferenceisaninstanceofaclass,butnotaninterface.

2）Theinstanceofoperatorcanbeusedtodetermineifareferenceisaninstanceofaparticularprimitivewrapperclass

3）Theinstanceofoperatorwillonlydetermineifareferenceisaninstanceofaclassimmediatelyaboveinthehierarchybutnofurtheruptheinheritancechain

4）Theinstanceofoperatorcanbeusedtodetermineifonereferenceisofthesameclassasanotherreferencethus

AnswertoQuestion6）

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Question7）

Whichofthefollowingstatementsaretrue?

1）Aninterfacecanonlycontainmethodandnotvariables

2）Interfacescannothaveconstructors

3）Aclassmayextendonlyoneotherclassandimplementonlyoneinterface

4）InterfacesaretheJavaapproachtoaddressingitslackofmultipleinheritance,butrequireimplementingclassestocreatethefunctionalityoftheInterfaces.

AnswertoQuestion7）

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Question8）

Whichofthefollowingarevalidstatements

1）publicclassMyCalcextendsMath

2）Math.max（s）;

3）Math.round（9.99,1）;

4）Math.mod（4,10）;

AnswertoQuestion8）

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Question9）

WhichofthefollowingaremethodsoftheRunnableinterface

1）run

2）start

3）yield

4）stop

AnswertoQuestion9）

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Question10）

Whichofthefollowingstatementsaretrue?

1）Abytecanrepresentbetween-128to127

2）Abytecanrepresentbetween-127to128

3）Abytecanrepresentbetween-256to256

4）Acharcanrepresentbetween-2x2pow162x2pow16-1

AnswertoQuestion10）

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Question11）

Whatwillhappenwhenyouattempttocompileandrunthefollowingcode

classBase{

publicvoidBase（）{

System.out.println（"Base"）;

}

}

publicclassInextendsBase{

publicstaticvoidmain（Stringargv[]）{

Ini=newIn（）;

}

}

1）CompiletimeerrorBaseisakeyword

2）Compilationandnooutputatruntime

3）OutputofBase

4）RuntimeerrorBasehasnovalidconstructor

AnswertoQuestion11）

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Question12）

Youhaveapublicclasscalledmyclasswiththemainmethoddefinedasfollows

publicstaticvoidmain（Stringparm[]）{

System.out.println（parm[0]）;

}

Ifyouattempttocompiletheclassandruntheprogramasfollows

javamyclasshello

Whatwillhappen?

1）Compiletimeerror,mainisnotcorrectlydefined

2）Runtimeerror,mainisnotcorrectlydefined

3）Compilationandoutputofjava

4）Compilationandoutputofhello

AnswertoQuestion12）

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Question13）

Whichofthefollowingstatementsaretrue?

1）Ifaclasshasanyabstractmethodsitmustbedeclaredabstractitself.

2）Allmethodsinanabstractclassmustbedeclaredasabstract

3）Whenappliedtoaclass,thefinalmodifiermeansitcannotbesub-classed

4）transientandvolatileareJavamodifiers

AnswertoQuestion13）

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Question14）

Whichofthefollowingarevalidmethods?

1）publicstaticnativevoidamethod（）{}

2）publicstaticvoidameticnativevoidamethod（）{}

3）privateprotectedvoidamethod（）{}

4）staticnativevoidamethod（）;

AnswertoQuestion14）

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Question15）

Whichofthefollowingstatementsaretrue?

1）Constructorscannothaveavisibilitymodifier

2）Constructorscanbemarkedpublicandprotected,butnotprivate

3）Constructorscanonlyhaveaprimitivereturntype

4）Constructorsarenotinherited

AnswertoQuestion15）

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Question16）

Whatwillhappenwhenyouattempttocompileandrunthefollowingclass?

classBase{

Base（inti）{

System.out.println（"Base"）;

}

}

classSevernextendsBase{

publicstaticvoidmain（Stringargv[]）{

Severns=newSevern（）;

}

voidSevern（）{

System.out.println（"Severn"）;

}

}

1）Compilationandoutputofthestring"Severn"atruntime

2）Compiletimeerror

3）Compilationandnooutputatruntime

4）Compilationandoutputofthestring"Base"

AnswertoQuestion16）

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Question17）

Whichofthefollowingstatementsaretrue?

1）staticmethodsdonothaveaccesstotheimplicitvariablecalledthis

2）Astaticmethodmaybecalledwithoutcreatinganinstanceofitsclass

3）Astaticmethodmaynotbeoverridentobenon-static

4）Astaticmethodmaynotbeoverloaded

Answertoquestion17）

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Question18）

Whichofthefollowingwillcompilewithouterror?

1）

charc='1';

System.out.println（c>>1）;

2）

Integeri=Integer（"1"）;

System.out.println（i>>1）;

3）

inti=1;

System.out.println（i<<<1）;

4）

inti=1;

System.out.println（i<<1）;

AnswertoQuestion18）

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Question19）

Whichofthefollowingaretrue?

1）Acomponentmayhaveonlyoneeventlistenerattachedatatime

2）Aneventlistenermayberemovedfromacomponent

3）TheActionListenerinterfacehasnocorrespondingAdapterclass

4）Theprocessingofaneventlistenerrequiresatry/catchblock

AnswertoQuestion19）

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Question20）

WhichofthefollowingareJavakeywords?

1）sizeof

2）main

3）transient

4）volatile

AnswertoQuestion20）

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Question21）

Whichofthefollowingstatementsaretrue?

1）Thedefaultconstructorhasareturntypeofvoid

2）Thedefaultconstructortakesaparameterofvoid

3）Thedefaultconstructortakesnoparameters

4）Thedefaultconstructorisnotcreatediftheclasshasanyconstructorsofitsown.

AnswertoQuestion21）

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Question22）

Whichofthefollowingstatementsaretrue?

1）Allofthevariablesinaninterfaceareimplicitlystatic

2）Allofthevariablesinaninterfaceareimplicitlyfinal

3）Allofthemethodsinaninterfaceareimplicitlyabstract

4）Amethodinaninterfacecanaccessclasslevelvariables

AnswertoQuestion22）

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Question23）

Whichofthefollowingstatementsaretrue?

1）TheStringclassisimplementedasachararray,elementsareaddressedusingthestringname[]convention

2）The+operatorisoverloadedforconcatenationfortheStringclass

3）StringsareaprimitivetypeinJavaandtheStringBufferisusedasthematchingwrappertype

4）Thesizeofastringcanberetrievedusingthelengthproperty

AnswertoQuestion23）

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Question24）

Whichofthefollowingstatementsaretrue?

1）Amethodinaninterfacemustnothaveabody

2）Aclassmayextendoneotherclassplusatmostoneinterface

3）Aclassmayextendsatmostoneotherclassplusimplementmanyinterfaces

4）Anclassaccessesaninterfaceviathekeyworduses

AnswertoQuestion24）

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Question25）

Whichofthefollowingstatementsaretrue?

1）Thefollowingstatementwillproducearesultof1.System.out.println（-1>>>2）;

2）Performinganunsignedleftshift（<<<）on