A system variable is a name assigned to a commonly used (and often variable) piece of information. For example, the current date is a commonly used piece of information that varies daily. It could be assigned the system variable name *TODAYS_DATE.
When a system variable is defined to LANSA, a name, description, method of derivation, type and length must be specified.
In addition, the name of a LANSA function or 3GL program that will "evaluate" the system variable must also be specified. It is this function/ program that is important because it provides the "intelligence" required to decide what is the correct value to place in the system variable.
When a system variable evaluation function/program is called by LANSA it is always passed 2 parameters. These are:
The evaluation program examples supplied are: