Functions

Each program we make will have a main() funciton. It's the first things that gets executed.

We can create other functions as well. We'll use three types of functions with the following properties:

1. Does not accept arguments - Has no return value
2. Accepts arguments - Has no return value
3. Does not accept arguments - Does have a return value
4. Accepts arguments - Does have a return value

The formulas for each of the three types are on the next three pages. Don't worry too much about memorizing them. We'll use each plenty of times.