logo

CuriousTab

CuriousTab

Discussion

Home ‣ Java Programming ‣ Java.lang Class See What Others Are Saying!
  • Question

  • What will be the output of the program? 
    public class ExamQuestion7 
{  
    static int j; 
    static void methodA(int i)
    {
        boolean b; 
        do
        { 
            b = i<10 | methodB(4); /* Line 9 */
            b = i<10 || methodB(8);  /* Line 10 */
        }while (!b); 
    } 
    static boolean methodB(int i)
    {
        j += i; 
        return true; 
    } 
    public static void main(String[] args)
    {
        methodA(0); 
        System.out.println( "j = " + j ); 
    } 
}


  • Options
  • A. j = 0
  • B. j = 4
  • C. j = 8
  • D. The code will run with no output

  • Correct Answer
  • j = 4 

    Explanation
    The lines to watch here are lines 9 & 10. Line 9 features the non-shortcut version of the OR operator so both of its operands will be evaluated and therefore methodB(4) is executed.

    However line 10 has the shortcut version of the OR operator and if the 1st of its operands evaluates to true (which in this case is true), then the 2nd operand isn't evaluated, so methodB(8) never gets called.

    The loop is only executed once, b is initialized to false and is assigned true on line 9. Thus j = 4.

    More questions

    • 1. What will be the output of the program? 
      public class A
{ 
    void A() /* Line 3 */
    {
        System.out.println("Class A"); 
    } 
    public static void main(String[] args) 
    { 
        new A(); 
    } 
}

    • Options
    • A. Class A
    • B. Compilation fails.
    • C. An exception is thrown at line 3.
    • D. The code executes with no output.
      • Discuss
    • 2. What will be the output of the program? 
      class Test 
{
    public static void main(String [] args) 
    {
        Test p = new Test();
        p.start();
    }

    void start() 
    {
        boolean b1 = false;
        boolean b2 = fix(b1);
        System.out.println(b1 + " " + b2);
    }

    boolean fix(boolean b1) 
    {
        b1 = true;
        return b1;
    }
}

    • Options
    • A. true true
    • B. false true
    • C. true false
    • D. false false
      • Discuss
    • 3. What will be the output of the program? 
      class Test 
{
    static int s;
    public static void main(String [] args) 
    {
        Test p = new Test();
        p.start();
        System.out.println(s);
    }

    void start() 
    {
        int x = 7;
        twice(x);
        System.out.print(x + " ");
    }

    void twice(int x) 
    {
        x = x*2;
        s = x;
    }
}

    • Options
    • A. 7 7
    • B. 7 14
    • C. 14 0
    • D. 14 14
      • Discuss
    • 4. You want a class to have access to members of another class in the same package. Which is the most restrictive access that accomplishes this objective?

    • Options
    • A. public
    • B. private
    • C. protected
    • D. default access
      • Discuss
    • 5. What will be the output of the program? 
      class Super
{ 
    public int i = 0; 

    public Super(String text) /* Line 4 */
    {
        i = 1; 
    } 
} 

class Sub extends Super
{
    public Sub(String text)
    {
        i = 2; 
    } 

    public static void main(String args[])
    {
        Sub sub = new Sub("Hello"); 
        System.out.println(sub.i); 
    } 
}

    • Options
    • A. 0
    • B. 1
    • C. 2
    • D. Compilation fails.
      • Discuss
    • 6. What will be the output of the program (in jdk1.6 or above)? 
      public class BoolTest 
{
    public static void main(String [] args) 
    {
        Boolean b1 = new Boolean("false");
        boolean b2;
        b2 = b1.booleanValue();
        if (!b2) 
        {
            b2 = true;
            System.out.print("x ");
        }
        if (b1 & b2) /* Line 13 */
        {
            System.out.print("y ");
        }
        System.out.println("z");
    }
}

    • Options
    • A. z
    • B. x z

      Aptitude

      Engineering

      Programming

      Reasoning

      Links

      Copyright ©CuriousTab. All rights reserved.