Java Default Method

A default method in Java is declared in an interface and has a default implementation. It provides a default implementation for an interface function, which can be overridden in an interface-implementing class.

Here is an example of a default method in Java:

public interface Vehicle {
   void start();
   void stop();
   
   default void honk() {
       System.out.println("Beep beep!");
   }
}

public class Car implements Vehicle {
   public void start() {
       System.out.println("Starting the car");
   }
   
   public void stop() {
       System.out.println("Stopping the car");
   }
   
   
   public static void main(String[] args) {
       Car car = new Car();
       car.start();    
       car.honk();     
       car.stop();     
   }
}

Output:

Starting the car
Beep beep!
Stopping the car

• The Vehicle interface has a default function honk() in this example, which gives a default implementation for the honk() method.
• The Car class implements the Vehicle interface and overrides the start(), stop(), and honk() methods, but not the honk() function.
• As a result, the honk() method in the Car class employs the Vehicle interface's default implementation.
• When an instance of the Car class executes its methods, the honk(), we can see that unction utilizes the default implementation and prints "Beep beep!" to the console.