3: Hierarchies and More Object-Oriented Programming

We have seen code boxing or organizing at two levels:

1. Methods, that is, naming a section of code.

2. Files/Classes, organizing data and methods into one bigger unit

Now we will expand the idea of organizing code to include relationships between files or classes, called hierarchies. We will do this by adding a rectangle to our exploration of shapes, from the previous chapter. This will bring us into a fuller understanding of object-oriented programming.