Anticlue

Abstract and Concrete classes

Before one can really get into patterns, and pattern analysis, its a good idea to understand the difference between concrete and abstract classes.

This is a basic concept of OO design and programming. Let's say you have alot of similar classes. For instance, you have a class for database administrators, client server programmers, web developers, and network specialists. If one was to group all of these under one category, they are all technicians. A web developer is a technician.

This grouping of related classes is an abstraction. The class technician is an abstract class. There are many methods of all database administrators, client server programmers, web developers, and network specialists that can be generically referred to as a technician's method. For instance all should know how to do analysis. The individual database administrators, client server programmers, web developers, and network specialists all represent a concrete class. They are specific types of technicians, but each one is a technician. The is a relationship is commonly referred to as inheritance.