重载和覆盖Word格式文档下载.docx
《重载和覆盖Word格式文档下载.docx》由会员分享,可在线阅读,更多相关《重载和覆盖Word格式文档下载.docx(14页珍藏版)》请在冰豆网上搜索。
1.publicclassRectangle{
2.}
3.
4.publicclassSquareextendsRectangle{
5.}
WhatistherelationshipbetweenRectangleandSquare?
b/*¾
Ø
Î
Ç
Ò
»
ö
Õ
ý
·
A.hasa
B.isa
C.It'
sbothanisaandhasarelationship.
D.Therelationshipisneitheranisaorahasarelationship.
4.Given:
1.publicclassVehicle{
2.privateEnginetheEngine;
3.}
4.
5.publicclassEngine{
6.}
WhatistherelationshipbetweenVehicleandEngine?
a/*¿
¨
³
¢
¶
¯
ú
B.isa
5.Given:
1.publicinterfaceMoveable{
2.publicvoidmoveObject();
5.publicclassBitmapimplementsMoveable{
6.publicvoidmoveObject(){
7.//bodyomitted
8.}
9.}
WhatistherelationshipbetweenMovableandBitmap?
b
A.hasa
D.Therelationshipisneitheranisanorahasarelationship.
6.Given:
1.classSuperTest{
2.publicdoublegetNumber(){
3.returnMath.random()*100;
4.}
6.
7.classTestextendsSuperTest{
8.publicintgetNumber(){
9.return(int)(Math.random()*100);
10.}
11.publicstaticvoidmain(String[]args){
12.Testt=newTest();
13.System.out.println(t.getNumber());
14.}
15.}
Whichoftheseresultscouldoccurfromthiscode?
(Chooseallthatapply)f/*×
À
à
Í
¡
A.59
B.34.234
C.134.234
D.134
E.100
F.Thiscodewillnotcompile.
7.Given:
8.publicintgetNumber(intmax){
9.return(int)(Math.random()*max);
11.
12.publicIntegergetNumber(intmax){
13.inttemp=(int)(Math.random()*max);
14.returnnewInteger(temp);
15.}
16.
17.publicstaticvoidmain(String[]args){
18.Testt=newTest();
19.System.out.println(t.getNumber());
20.}
21.}
Whichofthesestatementsistrue?
A.Thecodewillnotcompilecorrectlybecauseline19istryingtocallamethodthatdoesnotexistfortheclassTest.
B.Thecodedoesnotcompilebecauseofline12
C.Thecodedoesnotcompilebecauseofline14
D.Thereisnoambiguityastothereutrntypeinline12;
therefore,thiscodewillcompileandoutputadoublevalue
greaterthanorequalto0andlessthan100.
E.ThiscodewillnotcompilebecausethegetNumber()methodsintheTestclassmustallhavereturntypesofdouble.
8.Given:
1.publicclassA{
2.publicstaticvoidmain(String[]args){
3.newA().printResult(1,"
abc"
4);
5.privatevoidprintResult(inta,longb,intc){
6.System.out.println(a+b+c);
7.}
8.privatevoidprintResult(longa,Stringb,intc){
9.System.out.println(a+b+c);
11.}
A.ThecodewillnotcompilecorrectlybecausealongandaStringmaynotbeaddedtogetherinline9.
B.Thecodewillcompileandrunandwilldisplay1abc4inthestandardoutput.
B.Thecodewillcompileandrunandwilldisplay11234inthestandardoutput.
D.ThecodewillcompileandwillthrowaNumberFormatException.
9.Whenasubclassmethodhasthesamename,parameterlist,andreturntypeasamethodintheparentclass,thismethodissaidtobewhat?
d
A.Extended
B.Overloaded
C.Overextended
D.Overridden/*¸
²
10.Whichofthefollowingmustmatchexactlyforoverloadedmethodstocompilecorreclty?
(Choosethatallapply)d
A.Theparameterlist
B.Thereturntype
C.Theexceptionthrown
D.Noneoftheabove
11.Given:
1.publicclassTest{
2.publicstaticvoidmain(String[]args){
3.newTest().foo(1,2);
5.privatevoidfoo(inta,intb){
6.System.out.println("
int"
);
8.privatevoidfoo(longa,intb){
9.System.out.println("
long"
Whatwillhappenwhenyoucompileandrunthisprogram?
a
A.Thecodewillcompileandrun,anddisplayint.
B.Thecodewillcompileandrun,anddisplaylong.
C.Thecodewillnotcompile.
D.Thecodewillcompile,butthrowaruntimeexceptionwhenexecuted.
12.Given:
1.publicclassParent{
2.publicvoidexecute()throwsException{
3.//bodyomitted
4.}
6.publicclassChildextendsParent{
7.privatevoidexecute()throwsClassCastException{
8.//bodyomitted
9.}
10.}
Whatwillhappenwhenyoucompilethisprogram?
A.Theprogramwillcompilesuccessfully.
B.Theprogramwillnotcompilebecausetheexecute()inthesubclassthrowsadifferentexceptionthanintheparentclass.
C.Theprogramwillnotcompilebecausetheexecute()inthesubclasshaslessaccessibilitythanintheparentclass.
D.Theprogramwillnotcompilebecausetheexecute()inthesubclasshaslessaccessibliityandthrowsadifferentexceptionthanin
theparentclass.
13.Given:
2.publicvoidbaz(){
3.System.out.println("
A"
6.publicclassBextendsA{
7.publicstaticvoidmain(String[]args){
8.Aa=newB();
9.a.baz();
11.publicvodbaz(){
12.System.out.println("
B"
13.}
14.}
A.Theprogramcompiles,runs,anddisplayAinthestandardoutput.
B.Theprogramcompiles,runs,anddisplayBinthestandardoutput.
C.Theprogramcompiles,butthrowsaruntimeexception.
D.Theprogramdoesnotcompile.
14.Given:
3.newA().baz(1,2);
5.privatevoidbaz(inta,intb){
baz"
8.privatevoidfoo(inta,intb){
first"
11.privatebooleanfoo(inta,intb){
second"
13.returntrue;
Whichofthefollowingstatementsistrue?
A.Theprogramcompiles,runs,anddisplaysfirstinthestandardoutput.
B.Theprogramcompiles,runs,anddisplayssecondinthestandardoutput.
C.Theprogramcompiles,runs,anddisplaysbazinthestandardoutput.
15.Given:
2.protectedvoidstart()throwsClassCastException{
3.//bodyomitted
7.publicclassChildextendsTest{
8.publicvoidstart()throwsException{
9.//bodyomitted
B.Theprogramwillnotcompilebecausethestart()inthesubclassthrowsadifferentexceptionthanintheparentclass.
C.Theprogramwillnotcompilebecausethestart()inthesubclassispublic,whereasitisprotectedintheparentclass.
D.Theprogramwillnotcompilebecausethestart()inthesubclasshasdifferentaccessibilityandthrowsadifferentexceptionthanintheparentclass.
16.Whentwoormoremethodsinthesameclasshavethesamename,theyaresaidtobewhat?
A.Animplementationdetail
B.Overridden
C.Aninterface
D.Overloaded
17.Given:
1.publicclassExample{
3.newExample().locate(1.0,2);
5.privatevoidlocate(doublea,longb){
double-long"
8.privatevoidlocate(longa,intb){
long-int"
A.Thecodewillcompile,runanddisplaydouble-long.
B.Thecodewillcompile,runanddisplaylong-int.
18.Given:
2.publicSuperTest(){
Super!
"
8.publicstaticvoidmain(String[]args){
9.newTest();
11.publicTest(){
12.super();
13.this("
Great!
15.
16.publicTest(Stringname){
17.System.out.println(name);
18.}
19.}
Whatistheresultofthiscode?
f/*thisº
superÒ
ª
Å
Ô
£
¬
Ù
Æ
ð
A.Great!
B.Super!
C.Super!
D.Great!
E.Super!
19.Given:
3.newTest(4);
5.publicTest(){
okay"
8.publicTest(inti){
9.
11.}
Whichofthefollowinglinesofcodeshouldbeinsertedatline11sothattheoutputoftheprogramisokay?
c
A.super();
B.this;
C.Test();
D.this();
E.super();
20.Given:
1.publicclass