Chapter 6. Understanding Interfaces in ActionScript 2.0

In Chapter 5, "The Meek Shall Inherit the Earth," we talked about inheritance. If you recall, an object can inherit all the members of a class. The new class is called a subclass, or descendant, and the original class becomes a superclass, or ancestor. The relationship created between subclass and superclass is one-to-one. That is, a subclass can have one, and only one, ancestor . But what if you were trying to create a class that had the properties of two ancestors? Given the rules of inheritance and what we know at this point, we cannot have two direct ancestors .

This can be a problem.

Fortunately, in this chapter, we investigate an object-oriented concept called interfaces , which helps us implement multiple inheritance, but with a twist. We also see how interfaces can enhance what we already know about polymorphism.