Quiz Discussion

What will be the output of the following Java program?

    class A 
    {
        int i;
        void display() 
        {
            System.out.println(i);
        }
    }    
    class B extends A 
    {
        int j;
        void display() 
        {
            System.out.println(j);
        }
    }    
    class inheritance_demo 
    {
        public static void main(String args[])
        {
            B obj = new B();
            obj.i=1;
            obj.j=2;   
            obj.display();     
        }
   }

• 1]

  0

• 2]

  1

• 3]

  2

• 4]

  Compilation Error

What is not type of inheritance?

• 1]

  Single inheritance

• 2]

  Double inheritance

• 3]

  Hierarchical inheritance

• 4]

   Multiple inheritance

Which of these is correct way of inheriting class A by class B?

• 1]

  class B + class A {}

• 2]

  class B inherits class A {}

• 3]

  class B extends A {}

• 4]

  class B extends class A {}

Which of this keyword must be used to inherit a class?

• 1]

  super

• 2]

  this

• 3]

  extent

• 4]

  extends

Using which of the following, multiple inheritance in Java can be implemented?

• 1]

  Interfaces

• 2]

  Multithreading

• 3]

  Protected methods

• 4]

  Private methods

Which of the following is used in implementing inheritance through class?

• 1]

  inherited

• 2]

  using

• 3]

  extends

• 4]

  implements

Does Java support multiple level inheritance?

• 1]

  True

• 2]

  False

If super class and subclass have same variable name, which keyword should be used to use super class?

• 1]

  super

• 2]

  this

• 3]

  upper

• 4]

  classname

Static members are not inherited to subclass.

• 1]

  True

• 2]

  False

What will be the output of the following Java program?

    class A 
    {
        int i;
    }    
    class B extends A 
    {
        int j;
        void display() 
        {
            super.i = j + 1;
            System.out.println(j + " " + i);
        }
    }    
    class inheritance 
    {
        public static void main(String args[])
        {
            B obj = new B();
            obj.i=1;
            obj.j=2;   
            obj.display();     
        }
   }

• 1]

  2 2

• 2]

  3 3

• 3]

  2 3

• 4]

  3 2