logo

CuriousTab

CuriousTab

Discussion

Home ‣ Java Programming ‣ Declarations and Access Control See What Others Are Saying!
  • Question

  • Which three are valid method signatures in an interface?

    1. private int getArea();
    2. public float getVol(float x);
    3. public void main(String [] args);
    4. public static void main(String [] args);
    5. boolean setFlag(Boolean [] test);


  • Options
  • A. 1 and 2
  • B. 2, 3 and 5
  • C. 3, 4, and 5
  • D. 2 and 4

  • Correct Answer
  • 2, 3 and 5 

    Explanation
    (2), (3), and (5). These are all valid interface method signatures.

    (1), is incorrect because an interface method must be public; if it is not explicitly declared public it will be made public implicitly. (4) is incorrect because interface methods cannot be static.

    More questions

    • 1. 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
    • 2. 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
    • 3. 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.