hi, In some books, the following design patterns are listed: objects, classes, collaboration, sequence, deployment. But Dallas SCJD Study Group web site gives some different ones: Facade design, Factory Method Pattern, Proxy Design Pattern, Singleton Design Pattern, Visitor Pattern. How to classify the design pattern? How many are there? Thanks
There are hundreds, even thousands of patterns. See as a starting place http://hillside.net/patterns/ Pattern Almanac 2000, by Linda Rising is a good listing of all of them (and was recently given away at JavaRanch). Design Patterns CD: Elements of Reusable Object-Oriented Software by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides was th firt CS book on this topic.