SSD3单选.docx

SSD3单选.docx

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SSD3单选

1.1.1

1.ThenameofaJavasourcefile（d）

（a）mustbethesameastheclassitdefines,ignoringcase

（b）mustusetheextension.class

（c）hasnorestrictions

（d）mustbethesameastheclassitdefines,respectingcase

2.WhichmethodmustexistineveryJavaapplication?

（a）

（a）main

（b）paint

（c）init

（d）begin

1.1.3

1.Giventhefollowingcode,howmanytokenswillbeoutput?

（b）

StringTokenizerst=newStringTokenizer（"thisisatest"）;

while（st.hasMoreTokens（））{

stdOut.println（st.nextToken（））;

}

（a）1（b）4（c）0（d）3

2.ClassesfromwhichofthefollowingpackagesareimplicitlyimportedintoeveryJavaprogram?

（d）

（a）java.awt

（b）java.io

（c）java.util

（d）java.lang

3.Whatisthenameofthewrapperclassforthetypeint?

（d）

（a）integer

（b）Int

（c）INT

（d）Integer

4.ClassesfromwhichofthefollowingpackagesareimplicitlyimportedintoeveryJavaprogram?

（c）

（a）java.util

（b）java.awt

（c）java.lang

（d）java.io

5.Thetermwrapperclassesrefersto（a）

（a）acollectionofJavaclassesthat"wrap"Javaprimitivetypes

（b）theJavaclassesthatcontainatleasttwodatafields

（c）theJavaclassesthatcontainthemselves

（d）acollectionofJavaclassesthatcontainotherJavaclasses

6.WhatwillbeoutputcausedbytheexecutionofthefollowingJavaprogramsegment?

（c）

Stringname="Elvis";

System.out.print（name+"washere"）;

（a）name+washere

（b）Elviswashere

（c）Elviswashere

（d）namewashere

1.1.4

1.WhatwillbeoutputwhenthefollowingJavaprogramsegmentisexecuted?

（c）

intx=5;

inty=2;

System.out.println（x+y）;

（a）52

（b）5+2

（c）7

（d）52

2.Adifferencebetweenthemethodsprintandprintlnoftheclassjava.io.PrintWriteristhat（a）

（a）printlnappendsanewlinetotheendofitsoutput,butprintdoesnot

（b）printappendsanewlinetotheendofitsoutput,butprintlndoesnot

（c）printlninsertsanewlineatthebeginningofitsoutput,butprintdoesnot

（d）printinsertsanewlineatthebeginningofitsoutput,butprintlndoesnot

3.ConsiderthefollowingJavaprogramsegment.（c）

intx=5;

inty=2;

System.out.println（x+"1"+y）;

Whichofthefollowingstatementsistrueabouttheprogramsegment?

（a）Theoutputcausedbythecodewillbe8.

（b）Theoutputcausedbythecodewillbe512.

（c）Theoutputcausedbythecodewillbe512.

（d）Thecodewillcauseacompilationerror.

1.1.5

1.AllJavaexceptionclassesarederivedfromtheclass（a）

（a）java.lang.Throwable

（b）java.lang.Error

（c）java.lang.RuntimeException

（d）java.io.IOException

2.InJava,exceptionsthatarenothandledarepassedupthe（b）

（a）exceptionladder

（b）callstack

（c）blockhierarchy

（d）catchblocks

3.WhatistherightwaytohandleabnormalitiesininputonJava?

（d）

（a）Bywritingwhileloopstoguardagainstbadinput

（b）ByalwaysspecifyingthethrowsclauseineverymethodheaderwherefileI/Oisperformed

（c）ByusingtheclassFileFilterwhichgracefullyfiltersoutbadinputdata

（d）Byhandlingtheseproblemsbyprovidingexceptionhandlers

4.ConsiderthefollowingJavaprogramsegment.

importjava.io.*;

publicclassSomeClass{

publicvoidx（）{

thrownewRuntimeException（"Exceptionfromx"）;

}

publicvoidy（）{

thrownewIOException（"Exceptionfromy"）;

}

}

Whichofthefollowingistrueconcerningthedefinitionsforthemethodsxandy?

（a）

（a）xhasalegaldefinition,butyhasanillegaldefinition.

（b）xhasanillegaldefinition,butyhasalegaldefinition.

（c）Neitherxnoryhasalegaldefinition.

（d）Bothxandyhavelegaldefinitions.

1.1.6

1.WhichofthefollowingstatementsistrueoftheconventionsoutlinedbySunMicrosystemsinthedocumententitledCodeConventionsfortheJavaProgrammingLanguage?

（d）

TheydefineastandardinterfacedefinitionlanguagethatmustbeusedforallJavaclasses.

Theyproviderecommendationsintendedtomakesourcecodeeasiertoreadandunderstand.

TheydescribeonemechanismfornetworkcommunicationbetweenJavaandC++programs.

（a）IIIonly

（b）IandIIIonly

（c）I,II,andIII

（d）IIonly

Feedback:

Seesection1.1.6,subsection"CodeConvTOC"andsection1.1,subsection"WhyHaveCodeConventions,"inthecoursenotes.

2.AccordingtotheJavacodeconventions,filesthatcontainJavasourcecodehavethesuffix_____,andcompiledbytecodefileshavethesuffix_____.（d）

（a）.class,.javac

（b）.javac,.class

（c）.class,.java

（d）.java,.class

Feedback:

Seesection1.1.6,subsection"CodeConvTOC"andsection2.1,subsection"FileSuffixes,"inthecoursenotes.

3.AccordingtothedocumententitledCodeConventionsfortheJavaProgrammingLanguage,filesuffixesusedbyJavasoftwareincludewhichofthefollowing?

（b）

.obj

.class

.h

（a）IandIIIonly

（b）IIonly

（c）IandIIonly

（d）IIandIIIonly

1.1.7

1.WhichofthefollowingpatternsofcharactersopensaJavadoccommentblock?

（b）

（a）/*

（b）/**

（c）**/

（d）//

1.1.8

1.Afteratypicaldebuggerencountersabreakpoint,theprogrammerusingthedebuggermayperformwhichofthefollowingactions?

（a）

Examinethevaluesofvariablesinthehaltedprogram

Executethecurrentline

Resumeexecutionofthehaltedprogram

（a）I,II,andIII

（b）IandIIonly

（c）Ionly

（d）IIIonly

2.Inatypicalsource-codedebugger,aprogrammercanseta_____tocauseaprogramtostopexecutingataparticularlineofcode.（c）

（a）testcase

（b）stacktrace

（c）breakpoint

（d）printstatement

3.Astacktraceis（b）

（a）alistofvariablesallocatedonaprogram'sstack

（b）asequenceofmethodcalls

（c）onlyavailablethroughatypicaldebugger'sstepintofeature

（d）afatalerrorthatcausesatypicaldebuggertoterminate

4.Atoolthatallowsprogrammerstoexecutelinesofaprogramonelineatatimeinordertohelplocatethesourceofaprogram'serrorsisknownasa（n）（b）

（a）stacktrace

（b）debugger

（c）scope

（d）exceptionhandler

1.1.

1．AccordingtoJavadocconvention,thefirstsentenceofeachJavadoccommentshouldbe（c）

（a）an@authortag

（b）an@versiontag

（c）asummarysentenceofthedeclaredentry

（d）theorderoflinesisnotimportant

Feedback:

Seeformoreinformation.

1.2.1

1.InaUMLclassdiagram'srepresentationofaclass,thetop,middle,andlowerrectangularcompartmentsrespectivelydescribethe_____oftheclass.（c）

（a）attributes,methods,andname

（b）attributes,methods,andconstants

（c）name,attributes,andmethods

（d）name,methods,andconstants

2.UMLclassdiagramscandescribewhichofthefollowing?

（b）

Theinternalstructureofclasses

Relationshipsbetweenclasses

（a）Ionly

（b）IandII

（c）None

（d）IIonly

1.2.2

1.ConsiderthefollowingUMLclassdiagram.

Accordingtothediagram,instancesoftheclassnamed_____havereferencestoinstancesoftheclassnamed_____.（a）

（a）A,B

（b）A,C

（c）B,A

（d）B,C

2.ConsiderthefollowingUMLclassdiagram.

Accordingtothediagram,whichofthefollowingstatementsistrue?

（a）

（a）ClassAiscomposedofoneinstanceofClassBandoneormoreinstancesofClassC.

（b）ClassBandClassCarebothsubclassesofClassA.

（c）ClassBhasaone-to-oneassociationwithClassAandaone-to-manyassociationwithClassC.

（d）ClassAandClassBeachcontainatleastonereferencetoaninstanceofClassC.

3.Abinaryassociationissaidtoexistbetweentwoclasseswhen（a）

（a）anobjectofoneclassrequiresanobjectoftheotherclass

（b）oneclassisasubtypeoftheotherclass

（c）anobjectofoneclassisinstantiatedinthesamemethodasanobjectoftheotherclass

（d）oneclassbelongstothesamepackageastheotherclass

4.Themultiplicityofanassociationbetweentwoclassesindicatesthenumberof（a）

（a）instancesofoneclassthatcanbeassociatedwithaninstanceoftheotherclass

（b）methodsofoneclassthatarecalledbytheotherclass

（c）methodsandvariablescommontobothclasses

（d）timesthatoneclass'smethodsarecalledbytheotherclass

5.WhichofthefollowingistrueaboutassociationandaggregationinUMLclassdiagrams?

（c）

（a）Associationisaspecialformofaggregation.

（b）Associationistheoppositeofaggregation.

（c）Aggregationisaspecialformofassociation.

（d）Associationandaggregationhavenomeaningfulrelationship.

1.2.3

1.Acollectiontypicallymodelsa_____relationship.（b）

（a）many-to-many

（b）one-to-many

（c）zero-to-one

（d）one-to-one

2.ConsiderthefollowingUMLclassdiagram.（c）

Thediagramdescribesa

（a）relationshipbetweenasubclassandasuperclass

（b）one-to-onerelationship

（c）self-containingclass

（d）classwithoutmethods

3.Considertheclassdescribedbythefollowingdiagram:

Iftheclassrepresentsanemployeeandthebossattributereferstotheemployee'sboss,whichofthefollowingstatementsis（are）true?

（c）

Manyemployeescanhavethesameboss.

Oneemployeecanhavemanybosses.

（a）IIonly

（b）None

（c）Ionly

（d）IandII

4.ConsiderthefollowingUMLclassdiagram.

Whichofthefollowingis（are）trueaboutthesystemdescribedbythediagram?

（d）

AninstanceofPicturecancontainacollectionofinstancesoftheclassShape.

AninstanceofShapecancontainacollectionofinstancesoftheclassPicture.

（a）IIonly

（b）IandII

（c）None

（d）Ionly

5.Ifaclasshasanassociationwithitself,thentheclasscontains（b）

（a）amethodthatcallsitself

（b）anattributethatreferencesanobjectofthesameclass

（