Beginning C# 3.0

9.3. UML Light

The Unified Modeling Language (UML) is a standardized specification language for modeling objects. It evolved from a joint effort by James Rumbaugh, Grady Booch, and Ivar Jacobson in the 1990s. Entire volumes have been written on UML and there is no way that I can do justice to it here. Still, you can make use of a small subset of UML called a UML class diagram. This is a visual representation of the parts that comprise a class. Rather than use all the features of UML class diagrams, you use only a small subset, hence the term UML Light. (Don't bother Googling "UML Light". . . I made the term up.)

Figure 9-6 shows the general format for a UML class diagram.

Figure 9-6. Figure 9-6

A UML class diagram may be viewed as three stacked boxes. The top box holds the name of the class (in this case clsDates). This is the name you see on the cookie cutter when it's hanging on the wall. Below the class name box is a box that describes the properties of the class. (Other OOP languages might refer to these properties as class members or class attributes.) The third box describes the methods that this particular class supports. (The latest version of UML supports a fourth box that describes how the class is persisted, or permanently stored, in a disk data file or a database. Our light version ignores this fourth box.)

9.3.1. Access Specifiers

The first line in the properties ...