While the first publication of the Gang of Four's Design Patterns: Elements of Reusable Object- Oriented Software was released in October 1994, so far in this book, I have only been paying attention to design patterns over the last 10 to 12 years. Like most experienced developers, when I first started reading about design patterns, I recognized a lot of the patterns because I had already been using them without realizing what they were. Over the past 10 years or so, I do not believe I have written a serious application without using at least one of the Gang of Four's design patterns. I will tell you that I am definitely not a design pattern zealot, and if I get into a conversation about design patterns, there are usually only a couple of them that I can name without having to look them up. But the things that I do remember are the concepts...




















































