Types of Composition
Generally, there are two types of composition: association and aggregation. In both cases, these relationships represent collaborations between the objects. The stereo example we just used to explain one of the primary advantages of composition actually represents an association.
Is Composition a Form of Association?
Composition is another area in OO technologies where there is a question of which came first, the chicken or the egg. Some texts say that composition is a form of association, and some say that an association is a form of composition. In any event, in this book, we consider inheritance and composition the two primary ways to build classes. Thus, in this book, an association is a form of composition.
All forms ...