Java期末專項(xiàng)測(cè)試卷（一）

Java期末專項(xiàng)測(cè)試卷單選題（總共40題）1.單選題Theworst-timecomplexityforquicksortis_________.()(1分)A、O(1)B、O(logn)C、O(n)D、O(nlogn)E、O(n*n)答案：E解析：

暫無(wú)解析2.單選題Whatistheoutputofthefollowingcode?()

PublicclassTest{

Publicstaticvoidmain(String[]args){

NewPerson().printPerson();

NewStudent().printPerson();

}

}

ClassStudentextendsPerson{

@Override

PublicStringgetInfo(){

Return"Student";

}

}

ClassPerson{

PublicStringgetInfo(){

Return"Person";

}

PublicvoidprintPerson(){

System.out.println(getInfo());

}

}(1分)A、PersonPersonB、PersonStudentC、StduentStudentD、StudentPerson答案：B解析：

暫無(wú)解析3.單選題______________approachdividestheproblemintosubproblems,solvesthesubproblems,thencombinesthesolutionsofthesubproblemstoobtainthesolutionfortheentireproblem.Unlikethe________approach,thesubproblemsinthedivide-and-conquerapproachdon’toverlap.Asubproblemisliketheoriginalproblemwithasmallersize,soyoucanapplyrecursiontosolvetheproblem.()(1分)A、Divide-and-conquer/dynamicprogrammingB、Dynamicprogramming/divide-and-conquerC、Brutal-force/divide-and-conquerD、Backtracking/dynamicprogramming答案：A解析：

暫無(wú)解析4.單選題Analyzethefollowingcodeandchoosethebestanswer:()

PublicclassFoo{

Privateintx;

Publicstaticvoidmain(String[]args){

Foofoo=newFoo();

System.out.println(foo.x);

}

}(1分)A、Sincexisprivate,itcannotbeaccessedfromanobjectfoo.B、

SincexisdefinedintheclassFoo,itcanbeaccessedbyanymethodinsidetheclasswithoutusinganobject.Youcanwritethecodetoaccessxwithoutcreatinganobjectsuchasfoointhiscode.C、

Sincexisaninstancevariable,itcannotbedirectlyusedinsideamainmethod.However,itcanbeaccessedthroughanobjectsuchasfoointhiscode.D、Youcannotcreateaself-referencedobject;thatis,fooiscreatedinsidetheclassFoo.答案：C解析：

暫無(wú)解析5.單選題Whichofthefollowingclassescannotbeextended?()(1分)A、classA{}B、classA{privateA(){}}C、finalclassA{}D、classA{protectedA(){}}答案：C解析：

暫無(wú)解析6.單選題Thegift-wrappingalgorithmforfindingaconvexhulltakes______________time.()(1分)A、O(n)B、O(nlogn)C、O(logn)D、O(n^2)答案：D解析：

暫無(wú)解析7.單選題Thebest-timecomplexityforinsertionsortis_____________.()(1分)A、O(1)B、O(logn)C、O(n)D、O(nlogn)E、O(n*n)答案：C解析：

暫無(wú)解析8.單選題TocreateaninstanceofBigIntegerfor454,use()(1分)A、BigInteger(454);B、newBigInteger(454);C、BigInteger("454");D、newBigInteger("454");答案：D解析：

暫無(wú)解析9.單選題Supposelist1isanArrayListandlist2isaLinkedList.Bothcontains1milliondoublevalues.Analyzethefollowingcode:()

A-

For(inti=0;i<list1.size();i++)

Sum+=list1.get(i);

B-

For(inti=0;i<list2.size();i++)

Sum+=list2.get(i);(1分)A、CodefragmentArunsfasterthancodefragmentBB、CodefragmentBrunsfasterthancodefragmentAC、CodefragmentArunsasfastascodefragmentB答案：A解析：

暫無(wú)解析10.單選題SupposeTestSimpleCircleandSimpleCircleinListing9.1areintwoseparatefilesnamedTestSimpleCircle.javaandSimpleCircle.java,respectively.WhatistheoutcomeofcompilingTestsimpleCircle.javaandthenSimpleCircle.java?()(1分)A、OnlyTestSimpleCircle.javacompiles.B、OnlySimpleCircle.javacompiles.C、Bothcompilefine.D、Neithercompilessuccessfully.答案：C解析：

暫無(wú)解析11.TodeclareaninterfacenamedAwithagenerictype,use(1分)A、publicinterfaceA<E>{...}B、publicinterfaceA<E,F>{...}C、publicinterfaceA(E){...}D、publicinterfaceA(E,F){...}答案：A解析：

暫無(wú)解析12.單選題WhatisthereturnvalueforxMethod(4)aftercallingthefollowingmethod?()

StaticintxMethod(intn){

If(n==1)

Return1;

Else

Returnn+xMethod(n-1);

}(1分)A、12B、11C、10D、9答案：C解析：

暫無(wú)解析13.單選題ThetimecomplexityfortheTowersofHonoialgorithminthetextis________.()(1分)A、O(n)B、O(n^2)C、O(n^3)D、O(2^n)答案：D解析：

暫無(wú)解析14.單選題Whatisoutputofthefollowingcode:()

PublicclassTest{

Publicstaticvoidmain(String[]args){

Intlist[]={1,2,3,4,5,6};

For(inti=1;i<list.length;i++)

List[i]=list[i-1];

For(inti=0;i<list.length;i++)

System.out.print(list[i]+"");

}

}(1分)A、123456B、234566C、234561D、111111答案：D解析：

暫無(wú)解析15.單選題Therelationshipbetweenaninterfaceandtheclassthatimplementsitis()(1分)A、CompositionB、AggregationC、InheritanceD、None答案：C解析：

暫無(wú)解析16.單選題Analyzethefollowingcode.()

//Program1:

PublicclassTest{

Publicstaticvoidmain(String[]args){

Objecta1=newA();

Objecta2=newA();

System.out.println(a1.equals(a2));

}

}

ClassA{

Intx;

Publicbooleanequals(Aa){

Returnthis.x==a點(diǎn)x;

}

}

//Program2:

PublicclassTest{

Publicstaticvoidmain(String[]args){

Aa1=newA();

Aa2=newA();

System.out.println(a1.equals(a2));

}

}

ClassA{

Intx;

Publicbooleanequals(Aa){

Returnthis.x==a.x;

}

}(1分)A、Program1displaystrueandProgram2displaystrueB、Program1displaysfalseandProgram2displaystrueC、Program1displaystrueandProgram2displaysfalseD、Program1displaysfalseandProgram2displaysfalse答案：B解析：

暫無(wú)解析17.單選題Whatistheoutputofthefollowingcode?()

Int[]myList={1,2,3,4,5,6};

For(inti=myList.length-2;i>=0;i--){

MyList[i+1]=myList[i];

}

For(inte:myList)

System.out.print(e+"");(1分)A、123456B、612345C、623451D、112345E、234561答案：D解析：

暫無(wú)解析18.單選題Supposealistcontains{"red","green","red","green"}.Whatisthelistafterthefollowingcode?()

Stringelement="red";

For(inti=0;i<list.size();i++)

If(list.get(i).equals(element)){

List.remove(element);

I--;

}(1分)A、{"red","red","green"}B、{"red","green"}C、{"green","green"}D、{"green"}E、{}答案：C解析：

暫無(wú)解析19.單選題TheequalsmethodisdefinedintheObjectclass.WhichofthefollowingiscorrecttooverrideitintheStringclass?()(1分)A、publicbooleanequals(Stringother)B、publicbooleanequals(Objectother)C、publicstaticbooleanequals(Stringother)D、publicstaticbooleanequals(Objectother)答案：B解析：

暫無(wú)解析20.單選題Supposeyouchoosethefirstelementasapivotinthelist{5293840167}.Usingthepartitionalgorithminthebook,whatisthenewlistafterthepartition?()(1分)A、5293840167B、4230156798C、4213058967D、2340159867E、2340156789答案：C解析：

暫無(wú)解析21.單選題WhichofthefollowingdeclaresanabstractmethodinanabstractJavaclass?()(1分)A、publicabstractmethod();B、publicabstractvoidmethod();C、publicvoidabstractmethod();D、publicvoidmethod(){}E、publicabstractvoidmethod(){}答案：B解析：

暫無(wú)解析22.單選題WhatistheoutputofInteger.parseInt("10",2)?()(1分)A、1;B、2;C、10;D、Invalidstatement;答案：B解析：

暫無(wú)解析23.單選題Supposeyouchoosethefirstelementasapivotinthelist{5293840167}.Usingthepartitionalgorithminthebook,whatisthenewlistafterthepartition?()(1分)A、5293840167B、4230156798C、4213058967D、2340159867E、2340156789答案：C解析：

暫無(wú)解析24.單選題WhichofthefollowingareJavakeywords?()(1分)A、instanceOfB、instanceofC、castD、casting答案：B解析：

暫無(wú)解析25.單選題Thetimecomplexityforthetheclosestpairofpointsproblemusingdivide-and-conqueris________.()(1分)A、O(n)B、O(nlogn)C、O(logn)D、O(2^n)答案：B解析：

暫無(wú)解析26.單選題Analyzethefollowingcode:()

Double[]array={1,2,3};

ArrayList<Double>list=newArrayList<>(Arrays.asList(array));

System.out.println(list);(1分)A、Thecodeiscorrectanddisplays[1,2,3].B、Thecodeiscorrectanddisplays[1.0,2.0,3.0].C、Thecodehasacompileerrorbecauseanintegersuchas1isautomaticallyconvertedintoanIntegerobject,butthearrayelementtypeisDouble.D、ThecodehasacompileerrorbecauseasList(array)requiresthatthearrayelementsareobjects.答案：D解析：

暫無(wú)解析27.單選題Whatisthecorrecttermfornumbers[99]?()(1分)A、indexB、indexvariableC、indexedvariableD、arrayvariableE、array答案：C解析：

暫無(wú)解析28.單選題WhichofthedatatypesbelowcouldbeusedtostoreelementsintheirnaturalorderbasedonthecompareTomethod?()(1分)A、HashSetB、TreeSetC、LinkedHashSetD、CollectionE、Set答案：B解析：

暫無(wú)解析29.單選題Whatistheoutputofthefollowingcode:()

PublicclassTest{

Publicstaticvoidmain(String[]args){

Strings1=newString("Java");

Strings2=newString("Java");

System.out.print((s1==s2)+""+(s1.equals(s2)));

}

}(1分)A、falsefalseB、truetrueC、falsetrueD、truefalse答案：C解析：

暫無(wú)解析30.單選題IsArrayList<Integer>asubclassofArrayList<?>?()(1分)A、YesB、No答案：A解析：

暫無(wú)解析31.TodeclareaninterfacenamedAwithagenerictype,use(1分)A、publicinterfaceA<E>{...}B、publicinterfaceA<E,F>{...}C、publicinterfaceA(E){...}D、publicinterfaceA(E,F){...}答案：A解析：

暫無(wú)解析32.單選題Dothefollowingtwoprogramsproducethesameresult?()

ProgramI:

PublicclassTest{

Publicstaticvoidmain(String[]args){

Int[]list={1,2,3,4,5};

Reverse(list);

For(inti=0;i<list.length;i++)

System.out.print(list[i]+"");

}

Publicstaticvoidreverse(int[]list){

Int[]newList=newint[list.length];

For(inti=0;i<list.length;i++)

NewList[i]=list[list.length-1-i];

List=newList;

}

}

ProgramII:

PublicclassTest{

Publicstaticvoidmain(String[]args){

Int[]oldList={1,2,3,4,5};

Reverse(oldList);

For(inti=0;i<oldList.length;i++)

System.out.print(oldList[i]+"");

}

Publicstaticvoidreverse(int[]list){

Int[]newList=newint[list.length];

For(inti=0;i<list.length;i++)

NewList[i]=list[list.length-1-i];

List=newList;

}

}(1分)A、YesB、No答案：A解析：

暫無(wú)解析33.單選題Giventhefollowingcode:()

ClassC1{}

ClassC2extendsC1{}

ClassC3extendsC2{}

ClassC4extendsC1{}

C1c1=newC1();

C2c2=newC2();

C3c3=newC3();

C4c4=newC4();

Whichofthefollowingexpressionsevaluatestofalse?(1分)A、c1instanceofC1B、c2instanceofC1C、c3instanceofC1D、c4instanceofC2答案：D解析：

暫無(wú)解析34.單選題Analyzethefollowingcode.()

Importjava.util.*;

PublicclassTest{

Publicstaticvoidmain(String[]args)throwsException{

TreeSet<String>set=newTreeSet<>();

Set.add("Red");

Set.add("Yellow");

Set.add("Green");

Set.add("Blue");

SortedSettemp=set.headSet("Purple");

System.out.println(temp.first());

}

}(1分)A、TheprogramdisplaysRedB、TheprogramdisplaysBlueC、TheprogramdisplaysGreenD、TheprogramdisplaysYellowE、TheprogramdisplaysPurple答案：B解析：

暫無(wú)解析35.單選題Analyzethefollowingcode.Whichofthefollowingstatementsiscorrect?()

PublicclassTest{

Publicstaticvoidmain(String[]args){

Numberx=newInteger(3);

System.out.println(Value());

System.out.println(pareTo(newInteger(4)));

}

}(1分)A、TheprogramhasacompileerrorbecauseanIntegerinstancecannotbeassignedtoaNumbervariable.B、TheprogramhasacompileerrorbecauseintValueisanabstractmethodinNumber.C、TheprogramhasacompileerrorbecausexdoesnothavethecompareTomethod.D、Theprogramcompilesandrunsfine.答案：C解析：

暫無(wú)解析36.AssumeCalendarcalendar=newGregorianCalendar().__________returnsthemonthoftheyear.()(1分)A、calendar.get(Calendar.MONTH);B、calendar.get(Calendar.MONTH_OF_YEAR);C、calendar.get(Calendar.WEEK_OF_MONTH);D、calendar.get(Calendar.WEEK_OF_YEAR);答案：A解析：

暫無(wú)解析37.單選題Topreventaclassfrombeinginstantiated,_____________________()(1分)A、don'tuseanymodifiersontheconstructor.B、usethepublicmodifierontheconstructor.C、usetheprivatemodifierontheconstructor.D、usethestaticmodifierontheconstructor.答案：C解析：

暫無(wú)解析38.單選題The"lessthanorequalto"comparisonoperatorinJavais__________.()(1分)A、<B、<=C、=<D、<<E、!=答案：B解析：

暫無(wú)解析39.單選題Whatistheoutputofthefollowingcode?()

PublicclassTest{

Publicstaticvoidmain(String[]args){

Java.math.BigIntegerx=newjava.math.BigInteger("3");

Java.math.BigIntegery=newjava.math.BigInteger("7");

X.add(y);

System.out.println(x);

}

}(1分)A、3B、4C、10D、11答案：A解析：

暫無(wú)解析40.單選題15.AssumeCalendarcalendar=newGregorianCalendar().__________returnsthenumberofdaysinamonth.()(1分)A、calendar.get(Calendar.MONTH)B、calendar.get(Calendar.MONTH_OF_YEAR)C、calendar.get(Calendar.WEEK_OF_MONTH)D、calendar.get(Calendar.WEEK_OF_YEAR)E、calendar.getActualMaximum(Calendar.DAY_OF_MONTH)答案：E解析：

暫無(wú)解析多選題（總共40題）1.多選題SupposeArrayList<Double>list=newArrayList<>().Whichofthefollowingstatementsarecorrect?()(1分)A、list.add(5.5);//5.5isautomaticallyconvertedtonewDouble(5.5)B、list.add(3.0);//3.0isautomaticallyconvertedtonewDouble(3.0)C、DoubledoubleObject=list.get(0);//NocastingisneededD、doubled=list.get(1);//Automaticallyconvertedtodouble答案：ABCD解析：

暫無(wú)解析2.多選題TheGeometricObjectandCircleclassesaredefinedinthischapter.Analyzethefollowingcode.Whichstatementsarecorrect?()

PublicclassTest{

Publicstaticvoidmain(String[]args){

GeometricObjectx=newCircle(3);

GeometricObjecty=(Circle)(x.clone());

System.out.println(x);

System.out.println(y);

}

}(1分)A、Theprogramhasacompileerrorbecausetheclone()methodisprotectedintheObjectclass.B、Afteryouoverridetheclone()methodandmakeitpublicintheCircleclass,theproblemcancompileandrunjustfine,butyisnullifCircledoesnotimplementtheCloneableinterface.C、ToenableaCircleobjecttobecloned,theCircleclasshastooverridetheclone()methodandimplementthejava.lang.Cloneableinterface.D、IfGeometricObjectimplementsCloneableandCircleoverridestheclone()method,theclone()methodwillworkfinetocloneCircleobjects.答案：ABCD解析：

暫無(wú)解析3.WhichofthefollowingmethodsareintheCollectioninterface?(1分)A、add(o:E)B、addAll(c:Collection<?extendsE>)C、contains(o:Object):booleanD、containsAll(c:Collection<?>):boolean答案：ABCD解析：

暫無(wú)解析4.多選題Whichofthefollowingstatementsaretrue?()(1分)A、java.util.Listinheritsallthemethodsfromjava.util.Collection.Additionally,itcontainsnewmethodsformanipulatingalist.B、TheAbstractListclassprovidesapartialimplementationfortheListinterface.C、ArrayListisaconcreteimplementationofListusinganarray.D、LinkedListisaconcreteimplementationofListusingalinkedlist.LinkedListcontainsallthemethodsinListandadditionalnewmethodsformanipulatingalinkedlist.E、ListIteratorisasubinterfaceofIteratoranditprovidesthemethodstosupportbi-directionaltraversalofalist.答案：ABCDE解析：

暫無(wú)解析5.多選題Whichofthefollowingdatatypeshaveiterators?()(1分)A、HashSetB、TreeSetC、ArrayListD、LinkedListE、LinkedHashSet答案：ABCDE解析：

暫無(wú)解析6.多選題WhichofthefollowingarecorrectmethodsinMap?()(1分)A、containsKey(Objectkey)B、containsValue(Objectvalue)C、remove(Objectkey)D、remove(intindex)E、isEmpty()答案：ABCE解析：

暫無(wú)解析7.多選題Theelementsin________aresorted.()(1分)A、TreeSetB、ListC、TreeMapD、HashSetE、LinkedHashSet答案：AC解析：

暫無(wú)解析8.多選題Howcanyouinitializeanarrayoftwocharactersto'a'and'b'?()(1分)A、char[]charArray=newchar[2];charArray={'a','b'};B、char[2]charArray={'a','b'};C、char[]charArray={'a','b'};D、char[]charArray=newchar[]{'a','b'};答案：CD解析：

暫無(wú)解析9.多選題FillinthecodetocompletethefollowingmethodforcomputingaFibonaccinumber.()

Publicstaticlongfib(longindex){

If(index==0)//Basecase

Return0;

Elseif(index==1)//Basecase

Return1;

Else//Reductionandrecursivecalls

Return__________________;

}(1分)A、fib(index-1)B、fib(index-2)C、fib(index-1)+fib(index-2)D、fib(index-2)+fib(index-1)答案：CD解析：

暫無(wú)解析10.多選題WhichofthefollowingcomplexityisO(nlogn)?()(1分)A、300n+400n*nB、23nlogn+50C、45n+45nlogn+503D、n*n*n+nlogn答案：BC解析：

暫無(wú)解析11.多選題YoucanusethemethodsintheArraysclassto()(1分)A、findthemaximumobjectinanarraybasedonthecompareTomethod.B、findthemaximumobjectinanarrayusingaComparatorobject.C、sortanarray.D、shuffleanarray.E、doabinarysearchonanarray.答案：CE解析：

暫無(wú)解析12.多選題Whatiscorrectaboutapivot?()(1分)A、Apivotdividesalistintotwosublistsofequalsize.B、Apivotcanbechosenarbitrarily.C、Apivotdividesalistintotwosublists,theelementsinthefirstlistarenolargerthanthepivotandtheelementsinthesecondlistarelargerthanthepivot.D、Youshouldalwayschooseapivotthatdividesthelistevenly.答案：BC解析：

暫無(wú)解析13.多選題Toobtainthedistancebetweenthepoints(40,50)and(5.5,4.4),use_________.()(1分)A、distance(40,50,5.5,4.4)B、newPoint2D(40,50).distance(5.5,4.4)C、newPoint2D(40,50).distance(newPoint2D(5.5,4.4))D、newPoint2D(5.5,4.4).distance(40,50)E、newPoint2D(5.5,4.4).distance(newPoint2D(40,50))答案：BCDE解析：

暫無(wú)解析14.多選題SupposeListlist=newArrayList().Whichofthefollowingoperationsarecorrect?()(1分)A、list.add("Red");B、list.add(newInteger(100));C、list.add(newjava.util.Date());D、list.add(newArrayList());答案：ABCD解析：

暫無(wú)解析15.多選題SupposeListlist=newArrayList().Whichofthefollowingoperationsarecorrect?()(1分)A、list.add("Red");B、list.add(newInteger(100));C、list.add(newjava.util.Date());D、list.add(newArrayList());答案：ABCD解析：

暫無(wú)解析16.多選題Whichofthefollowingstatementswillconvertastringsintoiofinttype?()(1分)A、i=Integer.parseInt(s);B、i=(newInteger(s)).intValue();C、i=Integer.valueOf(s).intValue();D、i=Integer.valueOf(s);E、i=(int)(Double)parseDouble(s));答案：ABCDE解析：

暫無(wú)解析17.多選題Whichofthefollowingstatementsaretrue?()(1分)A、AnArrayListcangrowautomatically.B、AnArrayListcanshrinkautomatically.C、YoucanreducethecapacityofanArrayListbyinvokingthetrimToSize()methodonthelist.D、YoucanreducethecapacityofaLinkedListbyinvokingthetrimToSize()methodonthelist.答案：AC解析：

暫無(wú)解析18.多選題Whichofthefollowingisincorrect?()(1分)A、int[]a=newint[2];B、inta[]=newint[2];C、int[]a=newint(2);D、inta=newint[2];E、inta()=newint[2];答案：CDE解析：

暫無(wú)解析19.多選題Whichofthefollowingstatementsiscorrect?()(1分)A、Genericscanhelpdetecttypeerrorsatcompiletime,thusmakeprogramsmorerobust.B、Genericscanmakeprogramseasytoread.C、Genericscanavoidcumbersomecastings.D、Genericscanmakeprogramsrunfaster.答案：ABC解析：

暫無(wú)解析20.多選題WhichofthefollowingcomplexityisO(nlogn)?()(1分)A、300n+400n*nB、23nlogn+50C、45n+45nlogn+503D、n*n*n+nlogn答案：BC解析：

暫無(wú)解析21.多選題Analyzethefollowingcode:()

ArrayList<String>list=newArrayList<String>();

List.add("Beijing");

List.add("Tokyo");

List.add("Shanghai");

List.set(3,"HongKong");(1分)A、Thelastlineinthecodecausesaruntimeerrorbecausethereisnoelementatindex3inthearraylist.B、Thelastlineinthecodehasacompileerrorbecausethereisnoelementatindex3inthearraylist.C、Ifyoureplacethelastlinebylist.add(3,"HongKong"),thecodewillcompileandrunfine.D、Ifyoureplacethelastlinebylist.add(4,"HongKong"),thecodewillcompileandrunfine.答案：AC解析：

暫無(wú)解析22.多選題Whichofthefollowingstatementsaretrue?()(1分)A、java.util.Listinheritsallthemethodsfromjava.util.Collection.Additionally,itcontainsnewmethodsformanipulatingalist.B、TheAbstractListclassprovidesapartialimplementationfortheListinterface.C、ArrayListisaconcreteimplementationofListusinganarray.D、LinkedListisaconcreteimplementationofListusingalinkedlist.LinkedListcontainsallthemethodsinListandadditionalnewmethodsformanipulatingalinkedlist.E、ListIteratorisasubinterfaceofIteratoranditprovidesthemethodstosupportbi-directionaltraversalofalist.答案：ABCDE解析：

暫無(wú)解析23.多選題ToaddBigIntegerb1tob2,youwrite_________.()(1分)A、b1.add(b2);B、b2.add(b1);C、b2=b1.add(b2);D、b2=b2.add(b1);E、b1=b2.add(b1);答案：CD解析：

暫無(wú)解析24.多選題Whichofthefollowingarevalidspecifiersfortheprintfstatement?()(1分)A、%4cB、%10bC、%6dD、%8.2dE、%10.2e答案：ABCE解析：

暫無(wú)解析25.多選題Analyzethefollowingcode:()

PublicclassAextendsB{

}

ClassB{

PublicB(Strings){

}

}(1分)A、TheprogramhasacompileerrorbecauseAdoesnothaveadefaultconstructor.B、TheprogramhasacompileerrorbecausethedefaultconstructorofAinvokesthedefaultconstructorofB;butBdoesnothaveadefaultconstructor.C、TheprogramwouldcompilefineifyouaddthefollowingconstructorintoA-A(Strings){}D、TheprogramwouldcompilefineifyouaddthefollowingconstructorintoA-A(Strings){super(s);}答案：BD解析：

暫無(wú)解析26.多選題Whichofthefollowingis/arecorrect?()(1分)A、Aconstructormaybestatic.B、Aconstructormaybeprivate.C、Aconstructormayinvokeastaticmethod.D、Aconstructormayinvokeanoverloadedconstructor.E、Aconstructorinvokesitssuperclassno-argconstructorbydefaultifaconstructordoesnotinvokeanoverloadedconstructororitssuperclassconstructor.答案：BCDE解析：

暫無(wú)解析27.多選題Giventhefollowingcode,findthecompileerror.()

PublicclassTest{

Publicstaticvoidmain(String[]args){

M(newGraduateStudent());

M(newStudent());

M(newPerson());

M(newObject());

}

Publicstaticvoidm(Studentx){

System.out.println(x.toString());

}

}

ClassGraduateStudentextendsStudent{

}

ClassStudentextendsPerson{

@Override

PublicStringtoString(){

Return"Student";

}

}

ClassPersonextendsObject{

@Override

PublicStringtoString(){

Return"Person";

}

}(1分)A、m(newGraduateStudent())causesanerrorB、m(newStudent())causesanerrorC、m(newPerson())causesanerrorD、m(newObject())causesanerror答案：CD解析：

暫無(wú)解析28.多選題YoucanusethemethodsintheCollectionsclassto()(1分)A、findthemaximumobjectinacollectionbasedonthecompareTomethod.B、findthemaximumobjectinacollectionusingaComparatorobject.C、sortacollection.D、shuffleacollection.E、doabinarysearchonacollection.答案：AB解析：

暫無(wú)解析29.WhichofthefollowingmethodsareintheCollectioninterface?(1分)A、add(o:E)B、addAll(c:Collection<?extendsE>)C、contains(o:Object):booleanD、containsAll(c:Collection<?>):boolean答案：ABCD解析：

暫無(wú)解析30.多選題Whichofthefollowingstatementsistrue?()

(1分)A、Ifyoucompileaninterfacewithouterrors,a.classfileiscreatedfortheinterface.B、Ifyoucompileaclasswithouterrorsbutwithwarnings,a.classfileiscreated.C、Ifyoucompileaclasswitherrors,a.classfileiscreatedfortheclass.D、Ifyoucompileaninterfacewithouterrors,butwithwarnings,a.classfileiscreatedfortheinterface.E、classfileiscreatedforeachJavaclassandinterface.Butifithasacompileerror,no.classfileiscreated.答案：ABD解析：

暫無(wú)解析31.多選題Whichofthefollowingstatementsaretrue?(1分)A、TheComparableinterfacecontainsthecompareTomethodwiththesignature"publicintcompareTo(E)".B、TheComparatorinterfacecontainsthecomparemethodwiththesignature"publicintcompare(

E,E)".C、AComparableobjectcancomparethisobjectwiththeotherobject.D、AComparatorobjectcontainsthecomparemethodthatcomparestwoobjects.答案：ABCD解析：

暫無(wú)解析32.多選題Whichofthefollowingstatementsaretrue?()(1分)A、Adefaultconstructorisprovidedautomaticallyifnoconstructorsareexplicitlydeclaredintheclass.B、Atleastoneconstructormustalwaysbedefinedexplicitly.C、Everyclasshasadefaultconstructor.D、Thedefaultconstructorisano-argconstructor