NelsonMandella Wrote:C programs can become very complex and difficult to manage once they reach anywhere from approximately 10k to 20k lines of code. Modular code helps to mitigate this complexity, but it can also add complexity to what would be a short, simple program.

Yeah, that's pretty well put.

The best way to learn when and how to use globals is experience. For small programs, like say less than 10k lines of code, accessors are probably just getting in the way of getting the program done. Larger than that and using techniques for modularity (and debugging as DoG and Skorche pointed out) definitely start coming into play.

I will add this: As you are learning, I wouldn't worry toooo much about whether you're using globals or not, or how you specifically use them. As you start to become familiar with the language it does become more obvious what globals and parameters are really useful for.