10.6. Class diagrams

A Class can be seen as a blueprint for objects. A class is created for each type of object in a sequence or collaboration diagram. A class diagram shows the attributes and operations of classes in a system. Attributes and operations that are private, that is, that can only be accessed from within the class that contains them, are marked by a padlock icon. Class diagrams also show the relationships among the classes. The type of arrow connecting two classes, its direction, and its associated data all give important information about the relationship between the two connected classes.

Developers use class diagrams to develop the classes. Analysts use class diagrams to understand the details of the system. Architects also look at class diagrams to see the design of the system. Class diagrams help all members of the team to validate the functionality of the classes and the relationships among them.