武汉智远软件有限责任公司.doc
《武汉智远软件有限责任公司.doc》由会员分享，可在线阅读，更多相关《武汉智远软件有限责任公司.doc（18页珍藏版）》请在冰点文库上搜索。
选择题
1:
What will be the result of executing the following code?
// Filename; SuperclassX.java
package packageX;
public class SuperclassX
{
protected void superclassMethodX（）
{
}
int superclassVarX;
}
// Filename SubclassY.java
1.package packageX.packageY;
2.
3.public class SubclassY extends SuperclassX
4.{
5.SuperclassX objX = new SubclassY（）;
6.SubclassY objY = new SubclassY（）;
7.void subclassMethodY（）
8.{
9.objY.superclassMethodX（）;
10.int i;
11.i = objY.superclassVarX;
12.}
13.}
Choices:
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
2:
The following code is entire contents of a file called Example.java,causes precisely one error during compilation:
class SubClass extends BaseClass{
}
class BaseClass（）{
String str;
public BaseClass（）{
System.out.println（“ok”）;}
public BaseClass（String s）{
str=s;}}
public class Example{
public void method（）{
SubClass s=new SubClass（“hello”）;
BaseClass b=new BaseClass（“world”）;
}
}
Which line would be cause the error?
ThefollowingcodeisentirecontentsofafilecalledExample.java,causespreciselyoneerrorduringcompilation:
classSubClassextendsBaseClass{
}
classBaseClass（）{
Stringstr;
publicBaseClass（）{
System.out.println（“ok”）;}
publicBaseClass（Strings）{
str=s;}}
publicclassExample{
publicvoidmethod（）{
SubClasss=newSubClass（“hello”）;
BaseClassb=newBaseClass（“world”）;
}
}
Whichlinewouldbecausetheerror?
A.9
B.10
C.11
D.12
3:
鉴于Java的特点，它最适合的计算环境是
A.并行计算环境
B.分布式计算环境
C.高强度计算环境
D.开放式计算环境
4:
What will be printed when you execute the following code?
class X
{
Y b = new Y（）;
X（）
{
System.out.print（"X"）;
}
}
class Y
{
Y（）
{
System.out.print（"Y"）;
}
}
public class Z extends X
{
Y y = new Y（）;
Z（）
{
System.out.print（"Z"）;
}
public static void main（String[] args）
{
new Z（）;
}
}
Choices:
Whatwillbeprintedwhenyouexecutethefollowingcode?
classX
{
Yb=newY（）;
X（）
{
System.out.print（"X"）;
}
}
classY
{
Y（）
{
System.out.print（"Y"）;
}
}
publicclassZextendsX
{
Yy=newY（）;
Z（）
{
System.out.print（"Z"）;
}
publicstaticvoidmain（String[]args）
{
newZ（）;
}
}
Choices:
A.Z
B.YZ
C.XYZ
D.YXYZ
5:
Given the following class definition:
class A{
protected int i;
A（int i）{
this.i=i;
}
}
which of the following would be a valid inner class for this class?
Select valid answer:
Giventhefollowingclassdefinition:
classA{
protectedinti;
A（inti）{
this.i=i;
}
}
whichofthefollowingwouldbeavalidinnerclassforthisclass?
Selectvalidanswer:
A.classB{}
B.classBextendsA{}
C.classBextendsA{B（）{System.out.println（“i=”+i）;}}
D.classB{classA{}}
6:
下述程序代码中有语法错误的行是（ ）。
int i,ia[10],ib[10]; /*第一行*/
for （i=0;i<=9;i++） /*第2行*/
ia[i]=0; /*第3行*/
ib=ia; /*第4行*/
下述程序代码中有语法错误的行是（）。
inti,ia[10],ib[10];/*第一行*/
for（i=0;i<=9;i++）/*第2行*/
ia[i]=0;/*第3行*/
ib=ia;/*第4行*/
A.第1行
B.第2行
C.第3行
D.第4行
7:
Give this class outline:
class Example{
private int x;
//rest of class body…
}
Assuming that x invoked by the code java Example, which statement can made x be directly accessible in main（） method of Example.java?
Givethisclassoutline:
classExample{
privateintx;
//restofclassbody…
}
AssumingthatxinvokedbythecodejavaExample,whichstatementcanmadexbedirectlyaccessibleinmain（）methodofExample.java?
A.Changeprivateintxtopublicintx
B.changeprivateintxtostaticintx
C.Changeprivateintxtoprotectedintx
D.changeprivateintxtofinalintx
8:
假定a和b为int型变量,则执行下述语句组后,b的值为
a=1;
b=10;
do
{
b-=a;
a++;
}while（b--<0）;
A.9
B.-2
C.-1
D.8
9:
public class OuterClass {
private double d1 = 1.0;
//insert code here
}
You need to insert an inner class declaration at line 3. Which two inner class declarations are
valid?
publicclassOuterClass{
privatedoubled1=1.0;
//insertcodehere
}
Youneedtoinsertaninnerclassdeclarationatline3.Whichtwoinnerclassdeclarationsare
valid?
A.classInnerOne{publicstaticdoublemethoda（）{returnd1;}}
B.publicclassInnerOne{staticdoublemethoda（）{returnd1;}}
C.privateclassInnerOne{doublemethoda（）{returnd1;}}
D.staticclassInnerOne{protecteddoublemethoda（）{returnd1;}}
10:
WhicharenotJavakeywords?
A.TRUE
B.const
C.super
D.void
11:
Inthefollowingpiecesofcode,whichonewillcompilewithoutanyerror?
A.StringBuffersb1="abcd";
B.Booleanb=newBoolean（"abcd"）;
C.C:
byteb=255;
D.floatfl=1.2;
12:
public class X{
public Object m（）{
Object o = new Float（3.14F）;//line 3
Object [] oa = new Object[1];//line 4
oa[0] = o;//line 5
o=null;//line 6
return oa[0];//line 7
}
}
When is the Float object, created in line 3,eligible for garbage collection?
publicclassX{
publicObjectm（）{
Objecto=newFloat（3.14F）;//line3
Object[]oa=newObject[1];//line4
oa[0]=o;//line5
o=null;//line6
returnoa[0];//line7
}
}
WhenistheFloatobject,createdinline3,eligibleforgarbagecollection?
A.justafterline5.
B.justafterline6
C.justafterline7（thatis,asthemethodreturns）
D.neverinthismethod
13:
Give the following java source fragement:
//point x
public class Interesting{
//do something
}
Which statement is correctly Java syntax at point x?
Givethefollowingjavasourcefragement:
//pointx
publicclassInteresting{
//dosomething
}
WhichstatementiscorrectlyJavasyntaxatpointx?
A.publicclassMyClass{//dootherthing…}
B.staticintPI=3.14
C.classMyClass{//dosomething…}
D.none
14:
Whichofthefollowingstatementsarenotlegal?
A.longl=4990;
B.inti=4L;
C.doubled=34.4;
D.doublet=0.9F.
15:
What will happen when you attempt to compile and run the following code?
int Output = 10;
boolean b1 = false;
if（（b1 == true） && （（Output += 10） == 20））
{
System.out.println（"We are equal " + Output）;
}
else
{
System.out.println（"Not equal!
" + Output）;
}
Choices:
Whatwillhappenwhenyouattempttocompileandrunthefollowingcode?
intOutput=10;
booleanb1=false;
if（（b1==true）&&（（Output+=10）==20））
{
System.out.println（"Weareequal"+Output）;
}
else
{
System.out.println（"Notequal!
"+Output）;
}
Choices:
A.Compilationerror,attemptingtoperformbinarycomparisononlogicaldatatype
B.Compilationandoutputof"Weareequal10".
C.Compilationandoutputof"Notequal!
20".
D.Compilationandoutputof"Notequal!
10".
16:
What will be the result of executing the following code?
boolean a = true;
boolean b = false;
boolean c = true;
if （a == true）
if （b == true）
if （c == true） System.out.println（"Some things are true in this world"）;
else System.out.println（"Nothing is true in this world!
"）;
else if （a && （b = c）） System.out.println（"It's too confusing to tell what is true and what is false"）;
else System.out.println（"Hey this won't compile"）;
Choices:
Whatwillbetheresultofexecutingthefollowingcode?
booleana=true;
booleanb=false;
booleanc=true;
if（a==true）
if（b==true）
if（c==true）System.out.println（"Somethingsaretrueinthisworld"）;
elseSystem.out.println（"Nothingistrueinthisworld!
"）;
elseif（a&&（b=c））System.out.println（"It'stooconfusingtotellwhatistrueandwhatisfalse"）;
elseSystem.out.println（"Heythiswon'tcompile"）;
Choices:
A.Thecodewon'tcompile
B."Somethingsaretrueinthisworld"willbeprinted
C."Heythiswon'tcompile"willbeprinted
D.Noneofthese
17:
给出下面的代码片断。
。
。
下面的哪些陈述为错误的?
1） public void create（） {
2） Vector myVect;
3） myVect = new Vector（）;
4） }
给出下面的代码片断。
。
。
下面的哪些陈述为错误的?
1）publicvoidcreate（）{
2）VectormyVect;
3）myVect=newVector（）;
4）}
A.第二行的声明不会为变量myVect分配内存空间。
B.第二行语句创建一个Vector类对象。
C.第三行语句创建一个Vector类对象。
D.第三行语句为一个Vector类对象分配内存空间
18:
Whichstatementaboutlisteneristrue?
A.Mostcomponentallowmultiplelistenerstobeadded.
B.Ifmultiplelistenerbeaddtoasinglecomponent,theeventonlyaffectedonelistener.
C.Componentdon?
tallowmultiplelistenerstobeadd.
D.none
19:
Select valid identifier of Java:
Selectvalididentifi
升级会员 