Use of “this” keyword in formal parameters for static methods in C#

Question

I\'ve come across several instances of C# code like the following:

public static int Foo(this MyClass arg)

I haven\'t been able to find an

Answer 1

I just learnt this myself the other day: the this keyword defines that method has being an extension of the class that proceeds it. So for your example, MyClass will have a new extension method called Foo (which doesn't accept any parameter and returns an int; it can be used as with any other public method).