外包外企java面試題及答案是英文

外包外企java面試題及答案是英文

OutsourcingForeignEnterpriseJavaInterviewQuestionsandAnswers

Section1:SingleChoiceQuestions(10questions,2pointseach)

1.WhatisthefullformofJVM?

A.JavaVirtualMachine

B.JavaVirtualMemory

C.JavaVirtualManager

D.JavaVirtualMonitor

Answer:A

2.WhichofthefollowingisnotaprimitivedatatypeinJava?

A.int

B.float

C.String

D.double

Answer:C

3.WhatisthedefaultaccessmodifierforaclassmemberinJava?

A.public

B.private

C.protected

D.default(package-private)

Answer:D

4.Whatisthepurposeofthe'this'keywordinJava?

A.Tocallaconstructor

B.Tocallamethod

C.Toreferencethecurrentobject

D.Tocreateanewobject

Answer:C

5.InJava,howdoyouimplementaninterface?

A.Byextendingit

B.Byimplementingit

C.Byinheritingit

D.Byoverridingit

Answer:B

6.WhichofthefollowingisnotacollectionframeworkinterfaceinJava?

A.List

B.Map

C.Set

D.Object

Answer:D

7.Whatisthedifferencebetween'==’and'equals()'inJava?

A.'=='isforprimitivetypes,'equals()'isforobjectreferences

B.'=='isforobjectreferences,'equals()'isforprimitivetypes

C.'=='checksforvalueequality,'equals()'checksforreferenceequality

D.'=='checksforreferenceequality,'equals()'checksforvalueequality

Answer:D

8.WhatisthecorrectwaytodeclareavariableinJava?

A.int$number$

B.intnumber$

C.$intnumber$

D.intnumber

Answer:D

9.WhichJavakeywordisusedtocreateananonymousinnerclass?

A.new

B.this

C.super

D.extends

Answer:A

10.WhatistheoutputofthefollowingJavacodesnippet:

```

publicclassTest{

publicstaticvoidmain(String[]args){

inta=10;

intb=20;

System.out.println(++a+b--);

}

}

```

A.30

B.31

C.32

D.33

Answer:B

Section2:MultipleChoiceQuestions(10questions,2pointseach)

1.WhichofthefollowingarevalidJavamodifiers?(Chooseallthatapply)

A.public

B.private

C.protected

D.static

E.final

F.abstract

Answer:A,B,C,D,E,F

2.WhatarethecharacteristicsofafinalclassinJava?(Chooseallthatapply)

A.Itcannotbeextended

B.Itcanbeextended

C.Allitsmethodsarefinal

D.Itcanhaveabstractmethods

Answer:A,C

3.WhichofthefollowingarevalidwaystocreateathreadinJava?(Chooseallthatapply)

A.ByimplementingtheRunnableinterface

B.ByextendingtheThreadclass

C.ByusingtheExecutorService

D.Bycallingthestart()methodonanobject

Answer:A,B,C

4.WhatarethedifferenttypesofexceptionsinJava?(Chooseallthatapply)

A.Checkedexceptions

B.Uncheckedexceptions

C.Errors

D.RuntimeExceptions

Answer:A,B,C,D

5.WhichofthefollowingarevalidwaystohandleexceptionsinJava?(Chooseallthatapply)

A.Usingtry-catchblock

B.Usingfinallyblock

C.Usingthrowstatement

D.Usingthrowsclause

Answer:A,B,C,D

6.WhatarethedifferenttypesofgarbagecollectionmechanismsinJava?(Chooseallthatapply)

A.MarkandSweep

B.GenerationalCollection

C.CopyingCollection

D.ReferenceCounting

Answer:A,B,C

7.WhatarethedifferenttypesofJavaloops?(Chooseallthatapply)

A.forloop

B.whileloop

C.do-whileloop

D.foreachloop

Answer:A,B,C,D

8.WhatarethedifferenttypesofJavaaccessmodifiers?(Chooseallthatapply)

A.public

B.private

C.protected

D.default(package-private)

Answer:A,B,C,D

9.WhatarethedifferenttypesofJavareferencevariables?(Chooseallthatapply)

A.Objectreferences

B.Arrayreferences

C.Interfacereferences

D.Classreferences

Answer:A,B,C,D

10.WhatarethedifferenttypesofJavaannotations?(Chooseallthatapply)

A.@Override

B.@Deprecated

C.@SuppressWarnings

D.@FunctionalInterface

Answer:A,B,C,D

Section3:TrueorFalseQuestions(10questions,2pointseach)

1.TrueorFalse:Javaisacompiledlanguage.

Answer:False

2.TrueorFalse:Javasupportsmultipleinheritance.

Answer:False

3.TrueorFalse:The'null'keywordinJavacanbeassignedtoanyreferencevariable.

Answer:True

4.TrueorFalse:The'==’operatorinJavacanbeusedtocomparethecontentsoftwoStringobjects.

Answer:False

5.TrueorFalse:The'finally'blockinJavaisalwaysexecuted,regardlessofwhetheranexceptionisthrownornot.

Answer:True

6.TrueorFalse:Java's'switch'statementcanonlybeusedwithbyte,short,char,andint.

Answer:False

7.TrueorFalse:Java's'enum'isakeywordusedtodefineanenumeration.

Answer:True

8.TrueorFalse:Java's'assert'statementisusedfordebuggingpurposes.

Answer:True

9.TrueorFalse:Java's'synchronized'keywordcanbeusedtomakeamethodthread-safe.

Answer:True

10.TrueorFalse:Java's'volatile'keywordensuresthatavariableisnotcachedthread-locally.

Answer:True

Section4:ShortAnswerQuestions(4questions,5pointseach)

1.WhatisthedifferencebetweenamethodandaconstructorinJava?

Answer:Amethodisablockofcodethatperformsaspecifictaskandreturnsavalue,whileaconstructorisaspecialmethodusedtoinitializeobjectsofaclass.

2.ExplaintheconceptofpolymorphisminJava.

Answer:PolymorphisminJavaistheabilityofamethodoraconstructortotakemorethanoneform.Itallowsasubclasstoprovideaspecificimplementationofamethodthatisalreadydefinedinitssuperclass.

3.Whatisthepurposeofthe'try-with-resources'statementinJava?

Answer:The'try-with-resources'statementisusedtoensurethateachresourceisclosedattheendofthestatement.Itisatrystatementthatdeclaresoneormoreresources,andensuresthateachresourceisclosedattheendofthestatement.

4.WhatisthedifferencebetweenaninterfaceandanabstractclassinJava?

Answer:AninterfaceinJavaisacompletelyabstractclassthatcancontainonlyabstractmethodsandtypedeclarations.Anabstractclassisaclassthatcannotbeinstantiatedandmaycontainbothabstractandnon-abstractmethods.

Section5:DiscussionQuestions(4questions,5pointseach)

1.DiscusstheprosandconsofusingJava'sbuilt-incollectionframework.

Answer:(Thisisanopen-endedquestion,andtheanswershouldincludepointsabouttheefficiency,easeofuse,andlimitationsofthecollectionframework.)

2.ExplaintheimportanceofexceptionhandlinginJavaandprovideexamplesofbestpractices.

Answer:(Thisisanopen-endedquestion,andtheanswershouldincludepointsabouttheimportanceofhandlingexceptionstopreventprogramcrashesandmaintainprogramflow,aswellasexamplesofbestp