Objects and Inheritance:

Just like you can write code that calls a method even though you don't know what the data the method will be using when it is run, you also sometimes need to write code that calls methods even if you don't know exactly what METHOD will be called at runtime.

Swift/iOS has three basic ways to accomplish this.  We will eventually look at all three.

The first is called objects, inheritance, and method overriding.

Passing methods as parameters into other methods.

Delegates.