Summary

This appendix covered the UML. While it sounds like a programming language, it is really a standard way of drawing diagrams to represent structures and patterns of code. We only need 1 of the 14 recognized UML documents to get through this book, but the one we do use is used quite extensively.

The class diagram shows the structures of a system along with the relationships between those structures. The structures may be classes, interfaces, enumerations, and packages. Common relationships include inheritance, interface realization, composition, association, and more. Notes can be added to a diagram to add more details but should be kept concise.

We learned the best practices for UML class diagrams, including keeping a diagram as legible as possible. Avoid clutter in the diagram that comes from trying to define every single possible relationship between structures. Focus instead on those that are vital to the implementation of the diagram. A good diagram isn’t necessarily...