UML Weekend Crash Course™ - To Parent Directory

SESSION
9
Modeling the Static View:
The Class Diagram
Session Checklist
✔ Explaining the two diagrams in the Object Model
✔ Explaining and illustrating the Class diagram notation
✔ Explaining and illustrating attribute specifications
✔ Explaining and illustrating operation specifications
✔ Explaining and illustrating the different ways to represent a class
The Class diagram is by far the most used and best known of the object-oriented diagrams.
It is the source for generating code and the target for reverse engineering code.
Because the Class diagram is the primary source for code generation, the other diagrams
tend to serve as tools of discovery that add to your knowledge about how to build the
Class diagram. Use Cases identify the need for the objects as resources used by the system to
achieve its goals. The Sequence and Collaboration diagrams are excellent tools for discovering
object interactions and, by inference, defining interfaces. The Activity diagram is very
good for discovering the behavior implemented by objects and so helps to define the logic of
operations on the objects.
The Object Model
The phrase object model has been the source of some confusion. Object Model is often used
as a synonym for Class diagram. In this book, object model is used to mean the set of diagrams
used to model objects, namely the Class and Object diagrams. The Class diagram is the
more recognized and used of the two diagrams. The Object diagram is often implemented
within the Class diagram, not as a separate diagram. In fact, the UML specification does not
actually define the Object diagram. It is simply a Class diagram that contains only objects.