Creating the interface

Let's take a look at switch blocks in action. Create a new C# console app, clear out the existing code, and start typing this:

using static System.Console; 

We need this line, of course, so that we can use WriteLine. Next, we're going to make an interface that we'll call Movable:

interface Movable 
{ 
    void Move(); 
} 

This interface only has one method, called Move. Remember, the purpose of an interface is to bind a variety of different, essentially unrelated, class types together. What does this mean? It's basically a contract on the functionality, not data essentially. Let's take a look at this in action by implementing the interface.