interface

An interface defines a series of members the implementer must implement.

An interface itself doesn't provide any implementation.

A class can implement any number of interfaces.

A struct can implement interface as well.

An interface can only have methods, properties, events and indexers.

The following code defines an interface.

using System;

interface Printable{
    void Print();
   
}

class Rectangle : Printable{
    int Width;
    
    public void Print(){
       Console.WriteLine("Width:"+Width);
    }

}


class Test
{
    static void Main()
    {

        Printable r = new Rectangle();

        r.Print();

    }
}

The output:

Width:0