Method Overriding in Java - Runtime Polymorphism

Method Overriding

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

Rules:

Method must have same name as in parent class.

Must have same parameters.

Must be IS-A relationship (inheritance).

class Vehicle {
  void run() { System.out.println("Vehicle is running"); }
}
class Bike extends Vehicle {
  @Override
  void run() { System.out.println("Bike is running safely"); }
  
  public static void main(String args[]) {
    Bike obj = new Bike();
    obj.run(); // Calls Bike's run
  }
}