In this episode of Programming By Stealth, Bart explains one single concept, that of "Has-A". This is part 1 of 2, where next time we'll learn "Is-A" which is about inheritance. These both sound like odd terms but they're part of what makes object oriented programming so powerful. Bart spends 90% of the time going through a worked example which not only explains how classes can have instances of other classes as properties, but also how classes can be more specific versions of other classes. Along the way, I think he achieved his goal of cementing the foundation of getters and setters and Class functions and Instance functions. We'll see if I can use them in anger on the homework though!

You can find Bart's tutorial shownotes at [pbs.bartificer.net/...](https://pbs.bartificer.net/pbs98)h