[Java] Method Overriding

Method Overriding

- If subclass has the same method as declared in the parent class, it is known as method overriding

1. Usage

- Method overriding is used to provide specific implementation of a method that is already provided by its super class

- Method overriding is used for runtime polymorphism

2. Rule

- method must have same name as in the parent

- method must have same parameter

3. Problem without method overriding

class boss{ void run(){ System.out.println("I'm the boss"); } } public class Emp extends boss{ public static void main(String[]args){ Emp obj = new Emp(); obj.run(); } }

- Problem is that I have to provide a specific implementation of run() method

4. Example

package forLogic; class Vehicle{ String part(){ return "body"; } } class Bm extends Vehicle{ String part(){ return "tire"; } } class au extends Vehicle{ String part(){ return "window"; } } public class Test { public static void main(String[]args){ Bm t = new Bm(); au a = new au(); System.out.print(t.part()); System.out.print(a.part()); } }  

5. Question

1) Can we override static method?

- No, static method can't be overriden. It can be proved by runtime polymorphism

2) Why we can't overriden static method?

- Static method is bound with class whereas instance method is bound with object

- Static belongs to class area

- instance belongs to heap area