Question

In general Describe when, where, and how is super keyword used in a constructor.

Answer 1

Ans:-

Super keyword:-

* The super keyword refers to superclass (parent) objects. It is used inside a sub-class method definition to call a method defined in the super class. Private methods of the super-class cannot be called. Only public and protected methods can be called by the super keyword. It is also used by class constructors to invoke constructors of its parent class.

* The most common use of the super keyword is to eliminate the confusion between superclasses and subclasses that have methods with the same name. super() should be first statement inside any constructor. It can be used only inside constructor and nowhere else. super() is used to refer only parent class’s(super class’s) constructor.

* Super keyword (super() ) is used to call Base class’s constructor(i.e, Parent’s class).

How a super keyword used in a constructor can be understand by a simple program:-

class Parent {

    Parent()

    {

        System.out.println("Parent class's No " +

                              " arg constructor");

    }

}

class Child extends Parent {

    Child()

    {

        super();

        System.out.println("Flow comes back from " +

                        "Parent class no arg const");

    }

    public static void main(String[] args)

    {

        new Child();

        System.out.println("Inside Main");

    }

}