Method Over riding in Java

Method Overriding in Java :


If subclass (child class) has the same method as declared in the parent class, it is known as method overriding in Java.

In other words, If a subclass provides the specific implementation of the method that has been declared by one of its parent class, it is known as method overriding.

 

Usage of Java Method Overriding

  • Method overriding is used to provide the specific implementation of a method which is already provided by its superclass.
  • Method overriding is used for runtime polymorphism

 

Rules for Java Method Overriding

  1. The method must have the same name as in the parent class
  2. The method must have the same parameter as in the parent class.
  3. There must be an IS-A relationship (inheritance).

 

// normal parent and child class usage

class Vehicle{  
  void run(){System.out.println("Vehicle is running");}  
}  
 
//child class  
class Bike extends Vehicle{  
  public static void main(String args[]){  
 
  //creating  instance of child class  
  Bike obj = new Bike();  

  obj.run();  
  }  
}  

Method over riding :

class Vehicle{  
 
  //defining a method  
 
  void run(){System.out.println("Vehicle is running");}  
 
}  
//Creating a child class  
 
class Bike2 extends Vehicle{  
 
  //defining the same method as in the parent class  
 
  void run(){System.out.println("Bike is running safely");}  
  
  public static void main(String args[]){  
 
  Bike2 obj = new Bike2();//creating object  
 
  obj.run();//calling method  
  }  
} 


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