Design Patterns

• Resource: http://www.patterndepot.com/
• The Highlights-
• Though very abstract and theoretical, design patterns represent the ultimate in re-use.
• Many times, the same type of problem is solved more than once.  This is where design patterns are valuable.  They allow programmers to share and reapply object oriented code among projects and other programmers.
• I've used design patterns in my own software in the past.  Later, a fellow programmer will ask for advice on a completely unrelated problem, and I recommend the same pattern I used.  Thus, patterns are not tied to specific applications, but are general and can be re-used in many diverse programs.
• Many common patterns have names.  This reduces the learning curve significantly.  Instead of describing the inner workings of a program, you can simply say, "I used the command pattern here and the factory pattern here."  Other programmers who understand patterns will know what you mean.
• Many of the patterns have rules to help you program - you know what to declare private, abstract, etc.
• Design patterns describe the ways objects interact with each other.
• Design patterns gained wide acceptance in 1995, when Gamma, Helm, Johnson and Vlissides published a book, Design Patterns, Elements of Re-Usable Software.  This is commonly known as the Gang of Four (GoF) book.

Created by:  Brandan Jones December 17, 2001