Sunday, February 5, 2012

SCJP model question answer page 4


31)
class c2{
            final int i1;
            c2()
            {
                        i1=i1+1;
            }
            {
                        i1=2;
            }
            public static void main(String a[])
            {
                        c2 ob1=new c2();
                        System.out.println(ob1.i1);
            }
}


compile time error

prints 3

prints 2

none of the above

Ans: 1


32)
class C{
             public static void main(String a[])    
             {
              int i1=9;
              int i2;
              if(i1>3)
             {        
                    i2=8;
             }
               System.out.println(i2);
            }
}


compile time error

Runtim error

prints 8

prints 0

None of the above

Explanation:
since variable i1 is not final the value is not known at compiletime itself.so generate compile time error
Ans: 1


33)
class A extends Thread {
            public void run()
            {
                        System.out.print("A");
            }
}
class B {
public static void main (String[] args)
            {
            A a = new A();
            a.start();
            a.start();  // 1
            }
}


compile time error

Runtime Exception

the code compile and runs fine

none of the above

Explanation:
If the start method is invoked on a thread that is already running, then an IllegalThreadStateException will probably be thrown
Ans: 2


34)
class c1
{
            static{
                        System.out.println("static");
                    }
public static void main(String a[])
{
            System.out.println("main");
}
}


prints static main

prints main

prints main static

compiletime error

none of the above

Explanation:
No Explanation Available
Ans: 1


35)
class A{
            static String m(float i) {return "float";}
            static String m(double i) {return "double";}
            public static void main (String[] args) {
            int a1 = 1; long b1 = 2;
            System.out.print(m(a1)+","+ m(b1));
            }
}


prints float,foat

prints float,double

prints double,double

compile time error

None of the above

Explanation:
No Explanation Available
Ans: 1

36)
When a byte is added to a char, what is the type of the result?

byte

int

long

non of the above

Explanation:
The result of all arithmetic performed with the binary operators (not the assignment operators) is an int, a long, a float, or a double. Here byte and char are promoted to int, so the result is an int.
Ans: 2


37)
 class C extends Thread{
            public static void main(String argv[]){
            C b = new C();
            b.run();
  }
  public void start(){
          for (int i = 0; i <10; i++){
                  System.out.println("Value of i = " + i);
          }
  }

}



compile time error

runtime Exception

prints values from 0 to 9

None of the above

Explanation:
No Explanation Available
Ans: 4


38)
What is the signature of the run() method of the Runnable interface?

void run()

public void run(Runnable target)

public void run()

public static void run()

Ans: 3

39)
class C{
public static void main(String args[])
            {
            int a = 1;
            a += ++a + a++;
            System.out.print(a);
            }
}


compile time error

Runtime Exception

Prints 5

Prints 4

None of the above

Ans: 3

40)
interface I {           //1
  public class Inner {   ///2
         
          Inner ( ) {
                  System .out . println ( "Inner Created" ) ;
          }
  };
};


compile time error at line 1

compile time error at line 2

the code compiles fine

none of the above

Ans: 3

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