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
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
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
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");
question 15)
what will be output if you try to compile and run the following code, but 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
question 16)
which of the following statements are true?
1) methods cannot be overriden to be more private
2) static methods cannot be overloaded
3) private methods cannot be overloaded
4) an overloaded method cannot throw exceptions not checked in the base class
question 17)
what will happen if you attempt to compile and run the following code?
您现在的位置： 
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
question 18)
which of the following statements are true?
1) system.out.println( -1 >>> 2);will output a result larger than 10
2) system.out.println( -1 >>> 2); will output a positive number
3) system.out.println( 2 >> 1); will output the number 1
4) system.out.println( 1 <<< 2); will output the number
question 19)
what will happen when you attempt to compile and run the following code?
public class tux extends thread{
static string sname = "vandeleur";
public static void main(string argv[]){
tux t = new tux();
t.piggy(sname);
system.out.println(sname);
}
public void piggy(string sname){
sname = sname + " wiggy";
start();
}
public void run(){
for(int i=0;i < 4; i++){
sname = sname + " " + i;
}
}
}
1) compile time error
2) compilation and output of "vandeleur wiggy"
3) compilation and output of "vandeleur wiggy 0 1 2 3"
4) compilation and output of either "vandeleur", "vandeleur 0", "vandeleur 0 1" "vandaleur 0 1 2" or "vandaleur 0 1 2 3"
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
责任编辑：小草
