Overriding method is different than overloading, as in overloading of a method, their are more than one method with same name but different parameter with in same class unlike this, In overriding of a method, a method in child class(sub class) has the same name as of its parent class(super class).

Rules of overriding a method

• The method names must be same in this process.
• We can only overridden a instance method if child class inherit them.
• A method which is declared final by using final keyword can not be overridden.
• A child class which is in a different package can only override a non-final method which are declared either public or protected.
• we cannot overridden constructors.
• If we are unable to inherit a method, then we cannot overridden it.

Syntax

class className1
{
     // methods
     rtype1 methodName(parameter1)
     {
             //statements
     }
}

class className2 extends className1
{
     // methods
     rtype1 methodName(parameter1)
     {
             // statements
     }
}

eg:-

class Vehicle
{
      public void move()
      {
             System.out.println("Vehicle can move");
      }
}

class Bike extends Vehicle
{
     public void move()
      {
            System.out.println("Bike can move fast ");
      }
}

class MethodOverridingDemo
{
      public static void main(String args[])
      {
              Vehicle vehObj1 = new Vehicle(); 
              Bike bkObj = new Bike();
              Vehicle vehObj2 = new Bike(); 

              vehObj1.move();
              bkObj.move();

              vehObj2.move();   // Dynamic method dispatch
       }
}

Output

Vehicle can move
Bike can move fast
Bike can move fast