Method Overriding Late Data Binding in Java

Run time polymorphism (Method Overriding) (Late data binding)

It is a technique of defining a function more than one time without changing its signature (having same name and same parameter list).

Note: -- Method overriding cannot be achieved within single class function of base class is overrided in its derived class.

Method overriding is also called run time polymorphism or late data binding because the which function should be called by which statement is decided at time of execution.

SEE this program (What do you think is it method overriding?)à

import java.util.*;

class base

{

                void show()

                {

                                System.out.println("this is base class");

                }

}

class derived1 extends base

{

                void show()

                {

                                System.out.println("this is derived1 class");

                }

}

class derived2 extends base

{

                void show()

                {

                                System.out.println("this is derived2 class");

                }

}

public class abc

{

                public static void main(String as[])

                {

                                                base b;

                                                b=new base(); //instantiating  with base class cnstructor

                                                b.show();

                                               

                                                b=new derived1(); //instantiating  withderived1 class cnstructor

                                                b.show();

                                               

                                                b=new derived2(); //instantiating  with derived2 class cnstructor

                                                b.show();

                }

}

Output:--

                this is base class

this is derived1 class

this is derived2 class

yesssssssssssss this is method overriding

Here class derived1 and derived2 both class is getting inherited by class base hence method show() is also inherited in both classes and both derived1 and derived2 both class has its own show().

What is happening here is derived classes doesn’t have their own show() method but actually they are overriding the show() which comes from base class.

More in overriding (Abstract class) click HERE

http://shvicyberteam.blogspot.com/p/abstract-class-in-ava.html