| < Day Day Up > |
|
Rarely is an application comprised of just one class. In reality, applications are constructed from many classes. This chapter introduces you to the concepts and terminology associated with building complex application behavior from a collection of classes. This is referred to as compositional design or design by composition.
The study of compositional design is the study of aggregation and containment. You will learn the two primary aggregation associations: simple and composite.
In this chapter you will also learn how to extend the UML class diagram to describe the static relationship between classes in a complex application. To do this you will need to know how to express simple and composite aggregation visually.
The study of aggregation also entails learning how the whole class accesses the services of its part classes. The concept of message passing and sequencing will be demonstrated by introducing you to a new type of UML diagram known as the sequence diagram.
| < Day Day Up > |
|