Interfaces

Analogy: hardware

An Interface is like a Power Socket.

The socket doesn't care if you plug in a TV, a Laptop, or a Blender. As long as the plug fits (implements the interface), it works!

This allows you to swap out devices without changing the wiring of your house.

The Universal Adapter

We have a Plugable interface.

A Lamp lights up.
A Fan spins.
A Toaster heats up.

They all do different things, but they all fit into the same socket!

Universal Adapter (Interfaces)

Available Appliances

Interface Logic:

All these items implement the Plugable interface. The socket doesn't care what the item is, as long as it fits!

Select an appliance to plug in.

The Code

Define the "contract" (Interface):

Java Example

Switch language in Navbar

interface Plugable {
    void turnOn();
    void turnOff();
}

Implement it in different classes:

Java Example

Switch language in Navbar

class Lamp implements Plugable {
    public void turnOn() {
        System.out.println("Light!");
    }
    public void turnOff() {
        System.out.println("Darkness...");
    }
}