When working with the Observer Pattern and the Singleton Pattern it is easy to see how they relate to the Java or C++ versions of the same concept. Everything basically plugs into the same places you would expect, coming from another Object Oriented language. The implementation isn't all that different.
We are going to see something a little more interesting when working with the Strategy Pattern in Objective-C. The Strategy Pattern is one of the most basic patterns and is even covered in the introduction to Head First Design Patterns. While the concept is identical in Objective-C as it is in Java and C++, the implementation is much closer to languages with first-class functions such as Python.
To do this, we will take advantage of one of the more powerful features of Objective-C: Forwarding.
