测试无答案.docx
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测试无答案
Questions
1.Whatwillhappenwhenyouattempttocompileandrunthefollowingcode?
publicclassStatic
{
static
{
intx=5;
}
staticintx,y;
publicstaticvoidmain（Stringargs[]）
{
x--;
myMethod（）;
System.out.println（x+y+++x）;
}
publicstaticvoidmyMethod（）
{
y=x+++++x;
}
}
Choices:
a.Compiletimeerror
b.prints:
1
c.prints:
2
d.prints:
3
e.prints:
7
f.prints:
8
2.Giventhefollowingcode,whatwillbetheoutput?
classValue
{
publicinti=15;
}
publicclassTest
{
publicstaticvoidmain（Stringargv[]）
{
Testt=newTest（）;
t.first（）;
}
publicvoidfirst（）
{
inti=5;
Valuev=newValue（）;
v.i=25;
second（v,i）;
System.out.println（v.i）;
}
publicvoidsecond（Valuev,inti）
{
i=0;
v.i=20;
Valueval=newValue（）;
v= val;
System.out.println（v.i+""+i）;
}
}
Choices:
a.150
20
b.150
15
c.200
20
d.015
20
3.Whatwillhappenwhenyouattempttocompileandrunthefollowingcode?
classMyParent
{
intx,y;
MyParent（intx,inty）
{
this.x=x;
this.y=y;
}
publicintaddMe（intx,inty）
{
returnthis.x+x+y+this.y;
}
publicintaddMe（MyParentmyPar）
{
returnaddMe（myPar.x,myPar.y）;
}
}
classMyChildextendsMyParent
{
intz;
MyChild（intx,inty,intz）
{
super（x,y）;
this.z=z;
}
publicintaddMe（intx,inty,intz）
{
returnthis.x+x+this.y+y+this.z+z;
}
publicintaddMe（MyChildmyChi）
{
returnaddMe（myChi.x,myChi.y,myChi.z）;
}
publicintaddMe（intx,inty）
{
returnthis.x+x+this.y+y;
}
}
publicclassMySomeOne
{
publicstaticvoidmain（Stringargs[]）
{
MyChildmyChi=newMyChild（10,20,30）;
MyParentmyPar=newMyParent（10,20）;
intx=myChi.addMe（10,20,30）;
inty=myChi.addMe（myChi）;
intz=myPar.addMe（myPar）;
System.out.println（x+y+z）;
}
}
Choices:
a.300
b.240
c.120
d.180
e.Compilationerror
f.Noneoftheabove
4.Whatwillbetheresultofexecutingthefollowingcode?
1. booleana=true;
2. booleanb=false;
3. booleanc=true;
4. if（a==true）
5. if（b==true）
6. if（c==true） System.out.println（"Somethingsaretrueinthisworld"）;
7. else System.out.println（"Nothingistrueinthisworld!
"）;
8. elseif（a&&（b=c）） System.out.println（"It'stooconfusingtotellwhatistrueandwhatisfalse"）;
9. else System.out.println（"Heythiswon'tcompile"）;
Choices:
a. Thecodewon'tcompile
b."Somethingsaretrueinthisworld"willbeprinted
c."Heythiswon'tcompile"willbeprinted
d.Noneofthese
5. Whatwillhappenwhenyouattempttocompileandrunthefollowingcode?
interfaceMyInterface
{
}
publicclassMyInstanceTestimplementsMyInterface
{
staticStrings;
publicstaticvoidmain（Stringargs[]）
{
MyInstanceTestt=newMyInstanceTest（）;
if（tinstanceofMyInterface）
{
System.out.println（"Iamtrueinterface"）;
}
else
{
System.out.println（"Iamfalseinterface"）;
}
if（sinstanceofString）
{
System.out.println（"IamtrueString"）;
}
else
{
System.out.println（"IamfalseString"）;
}
}
}
Choices:
a.Compiletimeerror
b.Runtimeerror
c.Prints:
"Iamtrueinterface"followedby"IamtrueString"
d.Prints:
"Iamfalseinterface"followedby"IamfalseString"
e.Prints:
"Iamtrueinterface"followedby"IamfalseString"
f.Prints:
"Iamfalseinterface"followedby"IamtrueString"
6.Whatresultsfromattemptingtocompileandrunthefollowingcode?
publicclassTernary
{
publicstaticvoidmain（Stringargs[]）
{
inta=5;
System.out.println（"Valueis-"+（（a<5）?
9.9:
9））;
}
}
Choices:
a. prints:
Valueis-9
b.prints:
Valueis-5
c.Compilationerror
d.Noneofthese
7.Inthefollowingpiecesofcode,AandDwillcompilewithoutanyerror.True/False?
A:
StringBuffersb1="abcd";
B:
Booleanb=newBoolean（"abcd"）;
C:
byteb=255;
D:
intx=0x1234;
E:
floatfl=1.2;
Choices:
a.True
b.False
8.Consideringthefollowingcode,Whichvariablesmaybereferencedcorrectlyatline12?
1.publicclassOuter
2.{
3.publicinta=1;
4.privateintb=2;
5.publicvoidmethod（finalintc）
6.{
7.intd=3;
8.classInner
9.{
10.privatevoidiMethod（inte）
11.{
12.
13.}
14.}
15.}
16.}
Choices:
a.a
b.b
c.c
d.d
e.e
9.Whatwillbetheresultofexecutingthefollowingcode?
publicstaticvoidmain（Stringargs[]）
{
chardigit='a';
for（inti=0;i<10;i++）
{
switch（digit）
{
case'x':
{
intj=0;
System.out.println（j）;
}
default:
{
intj=100;
System.out.println（j）;
}
}
}
inti=j;
System.out.println（i）;
}
Choices:
a.100willbeprinted11times.
b.100willbeprinted10timesandthentherewillbearuntimeexception.
c.Thecodewillnotcompilebecausethevariableicannotbedeclaredtwicewithinthemain（）method.
d.Thecodewillnotcompilebecausethevariablejcannotbedeclaredtwicewithintheswitchstatement.
e.Noneofthese.
10.Whatwillhappenwhenyouattempttocompileandrunthefollowingcode?
classMyThreadextendsThread
{
publicvoidrun（）
{
System.out.println（"MyThread:
run（）"）;
}
publicvoidstart（）
{
System.out.println（"MyThread:
start（）"）;
}
}
classMyRunnableimplementsRunnable
{
publicvoidrun（）
{
System.out.println（"MyRunnable:
run（）"）;
}
publicvoidstart（）
{
System.out.println（"MyRunnable:
start（）"）;
}
}
publicclassMyTest
{
publicstaticvoidmain（Stringargs[]）
{
MyThreadmyThread = newMyThread（）;
MyRunnablemyRunnable=newMyRunnable（）;
Threadthread = newThread（myRunnable）;
myThread.start（）;
thread.start（）;
}
}
Choices:
a.Prints:
MyThread:
start（）followedbyMyRunnable:
run（）
b.Prints:
MyThread:
run（）followedbyMyRunnable:
start（）
c.Prints:
MyThread:
start（）followedbyMyRunnable:
start（）
d.Prints:
MyThread:
run（）followedbyMyRunnable:
run（）
e.Compiletimeerror
f.Noneoftheabove
11.Giventhecodebelow,andmakingnootherchanges,whichaccessmodifiers
（public,protectedorprivate）canlegallybeplacedbeforemyMethod（）online3?
Ifline3isleftasitis,whichkeywordscanlegallybeplacedbeforemyMethod
online8?
1.classHumptyDumpty
2.{
3.voidmyMethod（）{}
4.}
5.
6.classHankyPankyextendsHumptyDumpty
7.{
8.voidmyMethod（）{}
9.}
Choices:
a.privateornothing（i.e.leavingitasitis）online3.
Nothing（i.e.leavingitasitis）orprotectedorpublic
online8.
b.publicorprotectedonline3.privateornothing（i.e.leavingit
asitis）online8.
c.nothing（i.e.leavingitasitis）orprotectedorpublicon
line3.privateornothing（i.e.leavingitasitis）online8.
d.Noneoftheabove.
12. Whatwillbetheresultofexecutingthefollowingcode?
//Filename;SuperclassX.java
packagepackageX;
publicclassSuperclassX
{
protectedvoidsuperclassMethodX（）
{
}
intsuperclassVarX;
}
//FilenameSubclassY.java
1.packagepackageX.packageY;
2.
3.publicclassSubclassYextendsSuperclassX
4.{
5.SuperclassXobjX=newSubclassY（）;
6.SubclassYobjY=newSubclassY（）;
7.voidsubclassMethodY（）
8.{
9.objY.superclassMethodX（）;
10.inti;
11.i=objY.superclassVarX;
12.}
13.}
Choices:
a.Compilationerroratline5
b.Compilationerroratline9
c.Runtimeexceptionatline11
d.Noneofthese
13. Considertheclasshierarchyshownbelow:
--------------------------------------------------------------------
classFourWheelerimplementsDrivingUtilities
classCarextendsFourWheeler
classTruckextendsFourWheeler
classBusextendsFourWheeler
classCraneextendsFourWheeler
----------------------------------------------------------------------
Considerthefollowingcodebelow:
1.DrivingUtilitiesdu;
2.FourWheelerfw;
3.TruckmyTruck=newTruck（）;
4.du=（DrivingUtilities）myTruck;
5.fw=newCrane（）;
6.fw=du;
Whichofthestatementsbelowaretrue?
Choices:
a.Line4willnotcompilebecauseaninterfacecannotrefertoanobject.
b.Thecodewillcompileandrun.
c.Thecodewillnotcompilewithoutanexplicitcastatline6,becausegoing
downthehierarchywithoutcastingisnotallowed.
d.Thecodeatline4willcompileevenwithouttheexplicitcast.
e.Thecodewillcompileifweputanexplicitcastatline6butwillthrowanexceptionatruntime.
14.Whatresultsfromthefollowingcode?
1.classMyClass
2.{
3.voidmyMethod（inti）{System.out.println（"intversion"）;}
4.voidmyMethod（Strings）{System.out.println（"Stringversion"）;}
5.publicstaticvoidmain（Stringargs[]）
6.{
7.MyClassobj=newMyClass（）;
8.charch='c';
9.obj.myMethod（ch）;
10.}
11.}
Choices:
a.Line4willnotcompileasvoidmethodscan'tbeoverridden.
b.Anexceptionatline9.
c.Line9willnotcompileasthereisnoversionofmyMethodwhichtakesacharasargument.
d.Thecodecompilesandproducesoutput:
intversion.
e.Thecodecompilesandproducesoutput:
Stringversion.
15.Whatistheresultwhenyoucompileandrunthefollowingcode?
publicclassThrowsDemo
{
staticvoidthrowMethod（）
{
System.out.println（"InsidethrowMethod."）;
thrownewIllegalAccessException（"demo"）;
}
publicstaticvoidmain（Stringargs[]）
{
try
{
throwMethod（）;
}
catch（IllegalAccessExceptione）
{
System.out.println（"Caught"+e）;
}
}
}
Choices:
a.Compilationerror
b.Runt
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