Introduction - If you have any usage issues, please Google them yourself
GoF (" Gang of Four" Gang of Four, that Erich Gamma, Richard Helm, Ralph Johnson & John Vlissides four) of " design patterns" (published in 1995) is the first time raised to the level of theory design patterns, and the standardization. Book presents 23 kinds of basic design patterns, since, in the reusable object-oriented software development process, a large number of new design patterns emerging.