Visual Basic 2005 for Programmers: Deitel Developer Series, Second Edition

5.14. (Optional) Software Engineering Case Study: Identifying Class Attributes in the ATM System

In Section 4.9, we began the first stage of an object-oriented design (OOD) for our ATM system—analyzing the requirements document and identifying the classes needed to implement the system. We listed the nouns and noun phrases in the requirements document and identified a separate class for each one that plays a significant role in the ATM system. We then modeled the classes and their relationships in a UML class diagram (Fig. 4.22). Classes have attributes (data) and operations (behaviors). Class attributes are implemented in Visual Basic programs as properties and instance variables (and Shared variables, as we will see in Section 9.10), and class ...