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SCJP模拟试题[2](1)
添加时间: 2007-9-23 2:24:34 作者: JAVA题库 阅读次数:161 来源: http://www.d9soft.com
此套试题由60道题组成。
Questions
Question 1)
Which of the following lines will compile without warning or error.
a) float f = 1.3;
b) char c = "a";
c) byte b = 257;
d) boolean b = null;
e) int i = 10;
Question 2)
What will happen if you try to compile and run the following code
public class MyClass {
public static void main(String arguments[])
{
amethod(arguments);
}
public void amethod(String[] arguments)
{
System.out.println(arguments);
System.out.println(arguments[1]);
}
}
1) error Can't make static reference to void amethod.
2) error method main not correct
3) error array must include parameter
4) amethod must be declared with String
answer
-----------------------------------------
Question 3)
Which of the following will compile without error
1) import java.awt.*;
package Mypackage;
class Myclass {}
2) package MyPackage;
import java.awt.*;
class MyClass{}
3) /*This is a comment */
package MyPackage;
import java.awt.*;
class MyClass{}
answer
------------------------------------------
Question 4)
A byte can be of what size
1) -128 to 127
2) (-2 power 8 )-1 to 2 power 8
3) -255 to 256
4) depends on the Java Virtual machine
answer
-----------------------------------
Question 5)
What will be printed out if this code is run with the following command line
java myprog good morning
public class myprog{
public static void main(String argv[])
{
System.out.println(argv[2])
}
}
1) myprog
2) good
3) morning
4) Exception raised: "java.lang.ArrayIndexOutOfBoundsException: 2"
answer
---------------------------------------------
Question 6)
Which of the following are java reserved words
1) if
2) then
3) goto
4) while
5) case
answer
--------------------------------
Question 7)
Which of the following are legal identifiers
1) 2variable
2) variable2
3) _whatavariable
4) _3_
5) $anothervar
6) #myvar
answer
-----------------------------------------
Question 8)
What will happen when you compile the following code
public class MyClass{
static int i;
public static void main(String argv[]){
System.out.println(i);
}
}
1) Error Variable i may not have been initialized
2) null
3) 1
4) 0
answer
-----------------------------------------
Question 9)
What will happen if you try to compile and run the following code
public class Q {
public static void main(String argv[]){
int anar[]= new int[]{1,2,3};
System.out.println(anar[1]);
}
}
1) 1
2) Error anar is referenced before it is initialized
3) 2
4) Error size of array must be defined
answer
--------------------------------------------
Question 10)
What will happen if you try to compile and run the following code
public class Q {
public static void main(String argv[]){
int anar[]= new int[5];
System.out.println(anar[0]);
}
}
1) Error: anar is referenced before it is initialized
2) null
3) 0
4) 5
answer
-------------------------------------------
Question 11)
What will be the result of attempting to compile and run the following code
abstract class MineBase {
abstract void amethod();
static int i;
}
public class Mine extends MineBase
{
public static void main(String argv[]){
int[] ar = new int[5];
for(i = 0;i < ar.length;i++)
System.out.println(ar[i]);
}
}
1) a sequence of 5 0's will be printed
2) Error: ar is used before it is initialized
3) Error Mine must be declared abstract
4) IndexOutOfBoundes Error i
answer
-----------------------------------------------
Question 12)
What will be printed out if you attempt to compile and run the following code
int i = 1;
switch (i) {
case 0:
System.out.println("zero");
break;
case 1:
System.out.println("one");
case 2:
System.out.println("two");
default:
System.out.println("default");
}
1) one
2) one, default
3) one, two, default
4) default
answer
-------------------------------
Question 13)
What will be printed out if you attempt to compile and run the following code
int i = 9;
switch (i) {
default:
System.out.println("default");
case 0:
System.out.println("zero");
break;
case 1:
System.out.println("one");
case 2:
System.out.println("two");
}
1) default
2) default, zero
3) error default clause not defined
4) no output displayed
answer
----------------------------------------------
Question 14)
Which of the following lines of code will compile without error
1) int i=0;
if(i)
{
System.out.println("Hello");
}
2) boolean b = true;
boolean b2 = true;
if(b==b2)
{
System.out.println("So true");
}
3) int i=1;
int j = 2;
if(i ==1 j==2)
System.out.println("OK");
4)
int i=1;
int j = 2;
if(i ==1 & j==2)
System.out.println("OK");
answer
----------------------------------------------
Question 15)
What will be output if you try to compile and run the following code and and there is
no file called Hello.txt in the current directory.
import java.io.*;
public class Mine
{
public static void main(String argv[]){
Mine m = new Mine();
System.out.println(m.amethod());
}
public int amethod()
{
try {
FileInputStream dis = new FileInputStream("Hello.txt");
}catch (FileNotFoundException fne) {
System.out.println("No such file found");
return -1;
}catch(IOException ioe) {
} finally{
System.out.println("Doing finally");
}
return 0;
}
}
1) No such file found
2 No such file found ,-1
3) No such file found, doing finally, -1
4) 0
answer
----------------------------
Question 16)
What tags are mandatory when creating HTML to display an applet
1) name, height, width
2) code, name
3) codebase, height, width
4) code, height, width
answer
--------------------------------
Question 17)
What will happen if you attempt to compile and run the following code
class Base {}
class Sub extends Base {}
class Sub2 extends Base {}
public class CEx{
public static void main(String argv[]){
Base b = new Base();
Sub s = (Sub) b;
}
}
1) Compile and run without error
2) Compile time Exception
3) Runtime Exception
answer
----------------------------------------
Question 18)
If the following HTML code is used to display the applet in the code MgAp what will be displayed at the console.
<applet code = MgAp.class height=400 width=400 parameter HowOld=30 >
</applet>
import java.applet.*;
import java.awt.*;
public class MgAp extends Applet{
public void init(){
System.out.println(getParameter("age"));
}
}
1) Error no such parameter
2) 0
3) null
4) 30
answer
----------------------------------------------
Question 19)
You are browsing the Java HTML documentation for information on the
java.awt.TextField component. You want to create Listener code to respond to focus
events. The only Listener method listed is addActionListener. How do you go about
finding out about Listener methods.
1) Define your own Listener interface according to the event to be tracked
2) Use the search facility in the HTML documentation for the listener needed
3) Move up the hierarchy in the HTML documentation to locate methods in base
classes
4) Subclass awt.event with the appropriate Listener method
answer
-----------------------------------------
Question 20)
What will be displayed when you attempt to compile and run the following code
//Code start
import java.awt.*;
public class Butt extends Frame{
public static void main(String argv[]){
Butt MyBut= new Butt();
}
Butt(){
Button HelloBut = new Button("Hello");
Button ByeBut = new Button("Bye");
add(HelloBut);
add(ByeBut);
setSize(300,300);
setVisible(true);
}
}
//Code end
1) Two buttons side by side occupying all of the frame, Hello on the left and Bye on
the right
2) One button occupying the entire frame saying Hello
3) One button occupying the entire frame saying Bye
4) Two buttons at the top of the frame one saying Hello the other saying Bye
answer
------------------------------------
Question 21-50's answers are here.
Question 21:
In the following code fragment from an applet, we know that the getParameter call may return a null if there is no parameter named size. Which logical operator should replace X in line 5 to ensure that a NullPointerException is not generated if tmp is null.
1. int sz;
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