The LOWER-CASE function returns a character string that is the same length as argument-1 with each upper-case letter replaced
by the corresponding lower-case letter. The type of this function depends on the argument as follows:
- Argument-1 must be class alphabetic or alphanumeric
and must be at least one character in length.
- The same character string as argument-1 is returned, except that each upper-case letter is replaced by the corresponding lower-case
- The character string returned has the same length as argument-1.
- If the computer character set does not include lower-case letters, no changes take place in the character string.