Extending the Class Diagram

---

The UML class diagram can be used to show static relationships between classes in a software application. Figure 12-3 shows the UML class diagram for classes A and B as they appear in their final form in code examples 12.8 and 12.10.

Figure 12-3: UML Diagram Illustrating Simple Aggregation

The line between class B and Class A denotes an association. The open diamond placed at the class B end of the association denotes simple aggregation. The B class is the whole aggregate comprised of an A class part.

---