Exploring functions

The most fundamental module of any program in any programming language is the function. We’ve thrown around the term quite a bit, but what is a function? In the most basic sense, a function is a named, callable block of code that performs a task. Essentially, a well-written program will be a collection of functions.

With that being said, it is common for entry-level students and non-formally trained professionals to assume that a function is merely allocating functionality to separate files. This, however, is a major fallacy that can lead to a poorly written program that will not last. Though it is very common to split functions into separate files in PLC programming, a separate file is not a function. As such, it is important to remember that there is a major difference between code in separate files and functions.

What goes into a function?

Before we start writing functions, we need to determine what goes into a function and when a function needs...