Fundamentals of UML Diagrams
A diagram is the graphical presentation of a set of elements. UML has a lot of different diagrams. Make sure you can differentiate between different diagrams. Previous sections described UML diagrams; this section elaborates on them using examples.
Basic Use Case Notation
A Class Diagram
In Object Oriented design and development terms, a class has a name, a set of methods (also known as operations) and related data members (also known as attributes) as shown in Figure 2.1. Class by itself is not very useful. A large software system may
have thousands of classes, Modelling the relationships (association, inheritance, composition or aggregation) between them really defines systems behaviour.
Class diagrams show a set of classes, interfaces, and collaborations and their relationships. Class diagrams are the most common diagrams found in modelling object-oriented systems. It is an essential aspect of any Object Oriented Design method.
Class diagrams address the static design view of a system. They are used at the analysis stage as well as design. Class diagrams that include active classes address the static process view of a system. Class Diagram syntax is being used to draw a plan
of the major concepts for anyone to understand. This is called the Conceptual Model. Together with use cases, a conceptual diagram is a powerful technique in requirements analysis. Figure 2.2 shows an example of a class diagram.
Figure 2.2: An Example of a Class Diagram2.2.3