2026 Latest Java English Exam Questions and Answers英文英文英文

2026LatestJavaEnglishExamQuestionsandAnswers

ExamInstructions

1.TotalScore:100points

2.TotalQuestions:25(20MultipleChoice+3True/False+2ProgrammingQuestions)

3.AllquestionsarebasedonJava17officialspecification,coveringbasicsyntax,object-orientedprogramming,collectionframework,exceptionhandlingandcorefeatures.

Part1:MultipleChoiceQuestions(20questions,3pointseach,total60points)

Choosetheonlycorrectanswerforeachquestion

1.WhichofthefollowingisnotaprimitivedatatypeinJava?

A.char

B.int

C.String

D.boolean

Answer:C

Explanation:Javaprimitivedatatypesincludebyte,short,int,long,float,double,char,boolean.Stringisareferencetype(class),notaprimitivetype.

2.WhichfeaturemakesJavalanguageplatform-independent?

A.GarbageCollection

B.BytecodeandJVM

C.ExceptionHandling

D.Multithreading

Answer:B

Explanation:Javasourcecodeiscompiledintocross-platformbytecode,whichcanbeexecutedonanydevicewithJVMinstalled,realizingplatformindependence.

3.Whichmodifiermakesaclassmemberaccessibleonlywithinthesamepackage?

A.private

B.protected

C.default(package-private)

D.public

Answer:C

Explanation:Defaultaccessmodifier(nomodifier)allowsaccessonlywithinthesamepackage;privateisclass-level,protectedsupportssubclasscross-packageaccess,publicisglobalaccess.

4.Whichstatementaboutabstractclassesandinterfacesisfalse?

A.Abstractclassescanhaveconstructors

B.Interfacescannothaveconstructors

C.Abstractclassescannotcontainconcretemethods

D.InterfacessupportdefaultmethodssinceJava8

Answer:C

Explanation:Abstractclassescancontainbothabstractmethods(noimplementation)andconcretemethods(withimplementation).Onlyall-method-abstractinterfacesarecompletelyabstract.

5.Whichcollectionallowsduplicateelementsandmaintainsinsertionorder?

A.Set

B.List

C.Map

D.Queue

Answer:B

Explanation:Listinterface(ArrayList,LinkedList)allowsduplicateelementsandpreservesinsertionorder;Setprohibitsduplicates;Mapstoreskey-valuepairs.

6.Whichclasssupportsstoringnullkeyandnullvalues?

A.Hashtable

B.HashMap

C.TreeMap

D.ConcurrentHashMap

Answer:B

Explanation:HashMapallowsonenullkeyandmultiplenullvalues;HashtableandConcurrentHashMapdonotallownullkeysorvalues;TreeMapdoesnotallownullkeys.

7.Whatistheoutputofthefollowingcodesnippet?

PlainText

publicclassTest{

publicstaticvoidmain(String[]args){

intcount=5;

if(count++==++count){

System.out.println("EQUAL"+count);

}else{

System.out.println("NOTEQUAL"+count);

}

}

}

A.EQUAL6

B.NOTEQUAL7

C.EQUAL7

D.NOTEQUAL6

Answer:B

Explanation:count++ispost-increment(return5first,thencount=6),++countispre-increment(count=7first,return7).5!=7,finallycount=7.

8.WhichkeywordisusedtohandleruntimeexceptionsinJava?

A.throw

B.throws

C.try-catch

D.finally

Answer:C

Explanation:try-catchblockcatchesandhandlesruntimeexceptions;throwmanuallythrowsanexception;throwsdeclaresexceptions;finallyexecutescoderegardlessofexceptions.

9.Whichofthefollowingcannotbemodifiedafterinitialization?

A.staticvariable

B.finalvariable

C.localvariable

D.instancevariable

Answer:B

Explanation:Variablesmodifiedbyfinalareconstantsandcannotbereassignedafterinitialization;othervariabletypessupportvaluemodification.

10.WhatisthedefaultvalueofabooleanarrayelementinJava?

A.true

B.false

C.null

D.0

Answer:B

Explanation:Defaultvalueofbooleantypeisfalse;numerictypesdefaultto0,referencetypesdefaulttonull.

11.WhichmethodistheentrypointofaJavaprogram?

A.publicvoidmain()

B.publicstaticvoidmain(String[]args)

C.staticintmain()

D.publicstaticmain()

Answer:B

Explanation:ThestandardJavaprogramentrymethodmustbepublicstaticvoidmain(String[]args)withfixedmodifier,returntypeandparameterlist.

12.Whichloopexecutesthecodebodyatleastonce?

A.forloop

B.whileloop

C.do-whileloop

D.foreachloop

Answer:C

Explanation:do-whileloopexecutesthecodebodyfirst,thenjudgesthecondition,ensuringatleastoneexecution.

13.Whichinterfaceisusedforcustomizedmulti-criteriasorting?

A.Comparable

B.Comparator

C.Cloneable

D.Serializable

Answer:B

Explanation:Comparatorsupportsexternalmulti-rulesorting;Comparablerealizessinglenaturalsortinginsidetheclass.

14.WhatisthefunctionofJavaGarbageCollection(GC)?

A.Deleteallcodecomments

B.Recycleunusedheapmemoryobjects

C.Clearstackmemory

D.Optimizecodesyntax

Answer:B

Explanation:JavaGCautomaticallyidentifiesandreclaimsunreferencedobjectsinheapmemorytoavoidmemoryleaks.

15.WhichofthefollowingisavalidJavaidentifier?

A.123name

B.name_123

C.name@java

D.class

Answer:B

Explanation:Identifierscannotstartwithnumbers,containspecialsymbolsoruseJavakeywords;underscoresandlettersareallowed.

16.InJava,methodoverloadingrequires:

A.Samemethodname,differentparameterlists

B.Samemethodname,sameparameters,differentreturnvalues

C.Differentmethodnames

D.Samemodifier

Answer:A

Explanation:Methodoverloadingreferstomultiplemethodswiththesamenamebutdifferentparameterquantity,typeororderinthesameclass.

17.Whichkeywordisusedtoinheritaclass?

A.implement

B.extends

C.import

D.include

Answer:B

Explanation:extendsisusedforclassinheritance;implementisusedforinterfaceimplementation.

18.Whatdoesthesuperkeywordrepresent?

A.Currentclassobject

B.Parentclassobject/constructor

C.Staticobject

D.Nullobject

Answer:B

Explanation:superreferstotheparentclassinstance,usedtocallparentclassmethods,propertiesorconstructors.

19.Whichexceptionisacheckedexception?

A.NullPointerException

B.ArrayIndexOutOfBoundsException

C.IOException

D.ClassCastException

Answer:C

Explanation:IOExceptionisacheckedexceptionthatmustbedeclaredorcaught;theothersareruntimeuncheckedexceptions.

20.WhichpackageisautomaticallyimportedbyJVMforallJavaprograms?

A.java.util

B.java.lang

C.java.io

D.

Answer:B

Explanation:Thecoreclasses(String,Object,Math,etc.)injava.langpackageareautomaticallyimportedwithoutmanualimportstatements.

Part2:TrueorFalseQuestions(3questions,4pointseach,total12points)

WriteTforTrue,FforFalse

1.Javasupportsmultipleinheritanceforclasses.

Answer:F

Explanation:Javaonlysupportssingleclassinheritance,butallowsmultipleinterfaceimplementationtorealizemulti-inheritanceeffects.

2.Astaticmethodcanbecalleddirectlybytheclassnamewithoutcreatinganobject.

Answer:T

Explanation:Staticmethodsbelongtotheclassratherthaninstances,supportingdirectclassnameinvocation.

3.AllJavavariablesmustbeinitializedbeforeuse.

Answer:F

Explanation:Membervariableshavedefaultvalues;onlylocalvariablesmustbemanuallyinitializedbeforeuse.

Part3:ProgrammingQuestions(2questions,14pointseach,total28points)

WritecompleteandrunnableJavacode

Question1(14points)

WriteaJavaprogramtorealizeastudentscoremanagementfunction:defineaStudentclasswithnameandscoreattributes,andamethodtoprintstudentinformation.Create3studentobjects,storetheminanarray,andtraversetoprintallstudentinformation.

StandardAnswerCode:

PlainText

classStudent{

//Memberattributes

privateStringname;

privatedoublescore;

//Constructor

publicStudent(Stringname,doublescore){

=name;

this.score=score;

}

//Methodtoprintinformation

publicvoidshowInfo(){

System.out.println("StudentName:"+name+",Score:"+score);

}

}

publicclassScoreManager{

publicstaticvoidmain(String[]args){

//Createstudentarrayandobjects

Student[]students=newStudent[3];

students[0]=newStudent("Alice",92.5);

students[1]=newStudent("Bob",88.0);

students[2]=newStudent("Charlie",95.0);

//Traverseandprint

for(Studentstu:students){

stu.showInfo();

}

}

}

Question2(14points)

WriteaJavaprogramtojudgewhetherapositiveintegerinputbytheuserisaprimenumber(aprimenumberisanumbergreaterthan1thatcanonlybedividedby1anditself).

StandardAnswerCode:

PlainText

importjava.util.S