Façade Classes

Parametric polymorphism is a very powerful tool in the hands of those that understand it and a total mystery to others. We can build a baseclass with no real code just an interface that has no implementation.  This is legal but it does nothing.  Then we can create one of more classes which do something. We can pass into the façade class as this is called one or more parameters which decide which class or which implementation is to be used.  This creates very ‘generic’ and consistent coding. This is generally easy to maintain and can be written with the minimum number of lines of code. Programmers using objects written by other people do not have to get aware of the implementation details rather they can just check what are the methods & properties exposed by a particular class