Expression Types

GPP supports three types of expressions:

Numeric: floating point (or integer) numbers. Numeric expressions are always calculated with double precision floating point mathematics. Numeric expressions can be assigned to numeric variables.

String: character strings, up to 256 characters long. String expressions can be assigned to string variables.

Boolean: True or False expressions, which are only used in program control statements, such as IF or REPEAT UNTIL. Boolean expressions cannot be assigned to any variable or used as function arguments.

In the coming sections, the following conventions will be used to refer to expressions of various types:

<expr>                                An expression of any type

<num-expr>                       Numeric expression

<str-expr>                       String expression

<bool-expr>                    Boolean expression

The following variable names will be used in the expression examples:

X, Y                           Numeric user-defined variables

S1, S2                      String user-defined variables

AR                             A user-defined array variable