This function can be used to determine the type of an expression. The function returns a numeric value that describes the type of the argument. Although the numeric values are guaranteed to be the one defined here it is recommended that you use the predefined symbolic constant values to compare the return value of the function against. The function return value is the following
See also ISARRAY, ISSTRING, ISINTEGER, ISREAL, ISNUMERIC, ISDEFINED, ISUNDEF, ISEMPTY.