The ISDIGIT function checks that an expression consists entirely of numeric characters.
NOTE: This function is only available in jBASE 4.1 and later.
expression can return a result of any type. The ISDIGIT function will then return TRUE (1) if the expression consists entirely of numeric characters. The function will return FALSE (0) if any character in the expression is not numeric.
When the ISDIGIT function is used in International Mode the properties of each character are determined according to the Unicode Standard.