Variable Classes Automatic variables are more like the local variables of other high-level languages. If you are writing programs using a recursive algorithm, you will most likely want to use variables in the automatic class. Scope of Variables The scope of a variable refers to the range of programs that can see that variable. The following figureshows the scope of the different variable classes. A variable can be altered by the program(s) indicated in the shaded area of the box it is in plus any programs that are in smaller boxes. When a program declares an AUTO or LOCAL variable, any GLOBAL variables of the same name created in other programs are not accessible.
Variable Scoping Variable Scope Example shows an example of using the various variable classes. Notice that: l prog_1 declares a to be GLOBAL. Thus, it is available to all programs not having an AUTO or LOCAL a. l prog_2 creates an undeclared variable b. By default, b is GLOBAL and available to other eV+Language User's Guide, v2.x, 18318-000 Rev A Page 48