Variables are used because their values can change and they can be processed in many ways. If their values could not change, your programs would not be able to do anything interesting! The types of processing includes mathematical and logical operations, even if the intention is as simple as counting from 0 to 10.
Every variable is accessed using its name in your source code. A variable name can contain letters (A to Z, a to z), numbers (0 to 9) and the underscore character (_). The variable name cannot start with a number and the letters are case insensitive (so that "MY_VAR23" is the same as "my_var23").
Every variable also has a type, which determines what type of data it can hold, what the range of that data is and how much memory the variable uses.
| Previous topic | Chapter contents | Next topic |
|---|---|---|
| Introduction and Requirements | User Guide contents | Variable types |