益模软件Java笔试题doc.docx
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益模软件Java笔试题doc
益模软件Java笔试题
java笔试题目
QUESTIONNO:
1
1.publicclassTest{
2.publicstaticvoidmain（Stringargs[]）{
3.classFoo{
4.publicinti=3;
5.}
6.Objecto=（Object）newFoo（）;
7.Foofoo=（Foo）o;
8.System.out.println（“i=“+foo.i）;
9.}
10.}
Whatistheresult?
A.i=3
B.Compilationfails.
C.AClassCastExceptionisthrownatline6.
D.AClassCastExceptionisthrownatline7.
QUESTIONNO:
2
11.inti=1,j=10;
12.do{
13.if（i++>–j）{
14.continue;
15.}
16.}while（ij）{
14.break;
15.}
16.j–;
17.}while（++i<5）;
18.System.out.println（“i=”+i+”andj=“+j）;
Whatistheresult?
A.i=6andj=5
B.i=5andj=5
C.i=6andj=4
D.i=5andj=6
E.i=6andj=6
QUESTIONNO:
7
1.classSuper{
2.publicfloatgetNum（）{return3.0f;}
3.}
4.
5.publicclassSubextendsSuper{.
7.}
Whichmethod,placedatline6,causescompilationtofail?
A.publicvoidgetNum（）{}
B.publicvoidgetNum（doubled）{}
C.publicfloatgetNum（）{return4.0f;}
D.publicdoublegetNum（floatd）{return4.0d;}
QUESTIONNO:
8
Whichstatementistrue?
A.catch（Xx）cancatchsubclassesofX.
B.TheErrorclassisaRuntimeException.
C.AnystatementthatcanthrowanErrormustbeenclosedinatryblock.
D.AnystatementthatcanthrowanExceptionmustbeenclosedinatryblock.
E.AnystatementthatcanthrowaRuntimeExceptionmustbeenclosedinatry
block.
QUESTIONNO:
9
Whichthreeformpartofcorrectarraydeclarations?
（Choosethree）
A.publicinta[]
B.staticint[]a
C.public[]inta
D.privateinta[3]
E.privateint[3]a[]
F.publicfinalint[]a
QUESTIONNO:
10
1.publicclassFoo{
2.publicstaticvoidmain（String[]args）{
3.try{
4.return;
5.}finally{
6.System.out.println（“Finally”）;
7.}
8.}
9.}
Whatistheresult?
A.Finally
B.Compilationfails.
C.Thecoderunswithnooutput.
D.Anexceptionisthrownatruntime.
QUESTIONNO:
11
Given:
ClassOne.java:
1.packagecom.abe.pkg1;
2.publicclassClassOne{
3.privatecharvar=‘a’;
4.chargetVar（）{returnvar;}
5.}
ClassTest.java:
1.packagecom.abe.pkg2;
2.importcom.abc.pkg1.ClassOne;
3.publicclassClassTestextendsClassOne{
4.publicstaticvoidmain（String[]args）{
5.chara=newClassOne（）.getVar（）;
6.charb=newClassTest（）.getVar（）;
7.}
8.}
Whatistheresult?
A.Compilationfails.
B.Compilationsucceedsandnoexceptionsarethrown.
C.Anexceptionisthrownatline5inClassTest.java.
D.Anexceptionisthrownatline6inClassTest.java.
QUESTIONNO:
12
Given:
1.classTestA{
2.TestBb;
3.TestA（）{
4.b=newTestB（this）;
5.}
6.}
7.classTestB{
8.TestAa;
9.TestB（TestAa）{
10.this.a=a;
11.}
12.}
13.classTestAll{
14.publicstaticvoidmain（Stringargs[]）{
15.newTestAll（）.makeThings（）;
16.//…codecontinueson
17.}
18.voidmakeThings（）{
19.TestAtest=newTestA（）;
20.}
21.}
Whichtwostatementsaretrueafterline15,beforemaincompletes?
（Choosetwo）
A.Line15causesastackoverflow.
B.Anexceptionisthrownatruntime.
C.Theobjectreferencedbyaiseligibleforgarbagecollection.
D.Theobjectreferencedbybiseligibleforgarbagecollection.
E.Theobjectreferencedbyaisnoteligibleforgarbagecollection.
F.Theobjectreferencedbybisnoteligibleforgarbagecollection.
QUESTIONNO:
13
Given:
1.publicclassReturnIt{
2.returnTypemethodA（bytex,doubley）{
3.return（long）x/y*2;
4.}
5.}
WhatisthenarrowestvalidreturnTypeformethodAinline2?
A.int
B.byte
C.long
D.short
E.float
F.double
QUESTIONNO:
14
Given:
1.publicclassOuterClass{
2.privatedoubled1=1.0;
3.//insertcodehere
4.}
Whichtwoarevalidifinsertedatline3?
（Choosetwo）
A.staticclassInnerOne{
publicdoublemethoda（）{returnd1;}
}
B.staticclassInnerOne{
staticdoublemethoda（）{returnd1;}
}
C.privateclassInnerOne{
publicdoublemethoda（）{returnd1;}
}
D.protectedclassInnerOne{
staticdoublemethoda（）{returnd1;}
}
E.publicabstractclassInnerOne{
publicabstractdoublemethoda（）;
}
QUESTIONNO:
15
Given:
1.publicabstractclassTest{
2.publicabstractvoidmethodA（）;
3.
4.publicabstractvoidmethodB（）
5.{
6.System.out.println（“Hello”）;
7.}
8.}
Whichtwochanges,independentlyapplied,allowthiscodetocompile?
（Choosetwo）
A.AddamethodbodytomethodA.
B.Replacelines5–7withasemicolon（“;”）.
C.RemovetheabstractqualifierfromthedeclarationofTest.
D.RemovetheabstractqualifierfromthedeclarationofmethodA.
E.RemovetheabstractqualifierfromthedeclarationofmethodB.
QUESTIONNO:
16
Given:
1.interfaceBeta{}
2.
3.classAlphaimplementsBeta{
4.StringtestIt（）{
5.return“Tested”;
6.}
7.}
8.
9.publicclassMain1{
10.staticBetagetIt（）{
11.returnnewAlpha（）;
12.}
13.publicstaticvoidmain（String[]args）{
14.Betab=getIt（）;
15.System.out.println（b.testIt（））;
16.}
17.}
Whatistheresult?
A.Tested
B.Compilationfails.
C.Thecoderunswithnooutput.
D.Anexceptionisthrownatruntime.
QUESTIONNO:
17
Given:
1.publicclassExceptionTest{
2.classTestExceptionextendsException{}
3.publicvoidrunTest（）throwsTestException{}
4.publicvoidtest（）/*PointX*/{
5.runTest（）;
6.}
7.}
AtPointXonline4,whichcodeisnecessarytomakethecodecompile?
A.Nocodeisnecessary.
B.throwsException
C.catch（Exceptione）
D.throwsRuntimeException
E.catch（TestExceptione）
QUESTIONNO:
18
Giventhatbandcrefertoinstancesofwrapperclasses,whichtwostatementsare
true?
（Choosetwo）
A.b.equals（b）returnstrue.
B.b.equals（c）returnsthesameresultasb==c.
C.b.eqials（c）canreturnfalseevenifc.equals（b）returnstrue.
D.b.equals（c）throwsanexceptionifbandcaredifferentwrappertypes.
E.b.equals（c）returnsfalseifthetypeofwrapperobjectsbeingcomparedare
different.
QUESTIONNO:
19
Given:
11.try{
12.if（（newObject））（.equals（（newObject（））））{
13.System.out.println（“equal”）;
14.）else{
15.System.out.println（“notequal”）;
16.}
17.}catch（Exceptione）{
18.System.out.println（“exception”）;
19.}
Whatistheresult?
A.equal
B.notequal
C.exception
D.Compilationfails.
QUESTIONNO:
20
Given:
1.classBaseClass{
2.privatefloatx=1.of;
3.protectedfloatgetVar（）{returnx;}
4.}
5.classSubClassextendsBaseClass{
6.privatefloatx=2.Of;
7.//insertcodehere
8.}
Whichtwoarevalidexamplesofmethodoverridingwheninsertedatline7?
（Choose
two）
A.floatgetVar（）{returnx;}
B.publicfloatgetVar（）{returnx;}
C.publicdoublegetVar（）{returnx;}
D.protectedfloatgetVar（）{returnx;}
E.publicfloatgetVar（floatf）{returnf;}
QUESTIONNO:
21
Given:
1.publicclassSyncTest{
2.privateintx;
3.privateinty;
4.privatesynchronizedvoidsetX（inti）{x=i;}
5.privatesynchronizedvoidsetY（inti）{y=i;}
6.publicvoidsetXY（inti）{setX（i）;setY（i）;}
7.publicsynchronizedbooleancheck（）{returnx!
=y;}
8.}
Underwhichconditionwillcheckreturntruewhencalledfromadifferentclass?
A.checkcanneverreturntrue.
B.checkcanreturntruewhensetXYiscalledbymultiplethreads.
C.checkcanreturntruewhenmultiplethreadscallsetXandsetYseparately.
D.checkcanreturntrueonlyifSyncTestischangedtoallowxandytobeset
separately.
QUESTIONNO:
22
Given:
1.publicclassXimplementsRunnable{
2.privateintx;
3.privateinty;
4.
5.publicstaticvoidmain（String[]args）{
6.Xthat=newX（）;
7.（newThread（that））.start（）;
8.（newThread（that））.start（）;
9.}
10.
11.publicvoidrun（）{
12.for（;;）{
13.synchronized（this）{
14.x++;
15.y++;
16.}
17.
System.out.println（Thread.currentThread（）.getName（）+
18.“x=“+x+“,y=“+
y）;
19.}
20.}
21.}
Whatistheresult?
A.Compilationfails.
B.Theprogramprintspairsofvaluesforxandythatmightnotalwaysbethesameon
thesameline（forexample,“x=2,y=1”）.
C.Theprogramprintspairsofvaluesforxandythatarealwaysthesameonthesame
line（forexample,“x=1,y=1”）.
Inaddition,eachvalueappearsonlyonce（forexample,“x=1,y=1”followed
by“x=2,y=2”）.
Thethreadnameatthestartofthelineshowsthatboththreadsareexecuting
concurrently.
D.Theprogramprintspairsofvaluesforxandythatarealwaysthesameonthesame
line（forexample,“x=1,y=1”）.
Inaddition,eachvalueappearsonlyonce（forexample,“x=1,y=1”followed
by“x=2,y=2”）.
Thethreadnameatthestartofthelineshowsthatonlyasinglethreadisactually
executing.
QUESTIONNO:
23
Given:
1.//PointX
2.publicclassfoo{
3.publicstaticvoidmain（String[]args）throwsException{
4.jave.io.PrintWriterout=newjave.io.PrintWriter（
5.newjave.io.OutputStreamWriter（System.out）,true）;
6.out.println（“Hello”）;
7.}
8.}
WhichstatementatPointXonline1isrequiredtoallowthiscodetocompile?
A.Nostatementisrequired.
B.importjave.io.*;
C.includejava.io.*;
D.importjave.io.PrintWriter;
E.includejava.io.PrintWriter;
QUESTIONNO:
24
Whichtwoarevaliddeclarationsofafloat?
（Choosetwo）
A.floatf=1F;
B.floatf=1.0.;
C.floatf=‘1’;
D.floatf=“1”;
E.floatf=1.0d;
QUESTIONNO:
25
Whatisthenumericalrangeofachar?
A.0…32767
B.0…65535
310–035
LeadingthewayinITtestingandcertificationtools,
-65-
C.–256…255
D.–32768…32767
E.Rangeisplatformdependent.
QUESTIONNO:
26
Whichcodedeterminestheintvaluefooclosestto,butnotgreaterthan,a
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