This chapter's example code has two pieces: a library that defines a public function, and a console application that calls this function. Libraries are a great way to break up your applications, and while this example is simple, it also lets me show you how to create a library and include it in your application.
I'm going to stretch your imagination a bit; let's pretend that you're responsible for setting up a library of math functions. In this example, we'll only write one function, factorial. You should be able to recollect the factorial function from introductory programming; it's represented by a ! and is defined as follows:
- 0! is 1
- 1! is 1
- n! is n × (n - 1)!
This is a recursive definition and we can code it in the following way:
unsigned long factorial(unsigned int n)
{
switch(n)
...
