Chapter 4. Modeling a System s Logical Structure: Introducing Classes and Class Diagrams

Chapter 4. Modeling a System's Logical Structure: Introducing Classes and Class Diagrams

Classes are at the heart of any object-oriented system; therefore, it follows that the most popular UML diagram is the class diagram. A system's structure is made up of a collection of pieces often referred to as objects. Classes describe the different types of objects that your system can have, and class diagrams show these classes and their relationships. Class relationships are covered in Chapter 5.

Use cases describe the behavior of your system as a set of concerns. Classes describe the different types of objects that are needed within your system to meet those concerns. Classes form part of your model's logical view, as shown in Figure 4-1.

Figure 4-1. The Logical View on your model contains the abstract descriptions of your system's parts, including classes