Expressions

Expressions are [Literals], functions and references documented on page [Built-in Names], calls to user-defined functions, names of initialized variables in the format of [Names], references to initialized elements of arrays, and combinations thereof with [Operators].

That is, it is an error to mention in an expression:

• a new variable name that is not (yet) initialized,
• an array that is neither defined via DIM nor built in,
• an element of an existing array that is not (yet) initialized, or
• a function that is neither defined via DEF nor built in.

Expressions are evaluated as soon as the runner encounters them in the program flow. They may appear in certain instructions' arguments, and the instruction will always consider the value of the expression. See [Evaluations] page for more details.