The $CHAR function returns a string of one or more characters corresponding to integer ASCII codes specified in its argument(s).
The format for the $CHAR function is:
$C[HAR](intexpr[,...])
The integer expression(s) specify the ASCII codes of the character(s) $CHAR() returns.
The M standard does not restrict the number of arguments to $CHAR(). However, GT.M does limit the number of arguments to a maximum of 254. $CHAR() provides a means of producing non-graphic characters, as such characters cannot appear directly within an M string literal. Used with $ASCII(), $CHAR() can also perform arithmetic operations on the codes associated with characters.