11-24-2014 12:53 PM
: modifier means to apply the operator to truncated data. The match is only up to the length of the shorter of the two arguments.
So in this case it means that values of FIRST_NAME that begin with AND will be copied into the FNAME variable. But since it truncates both arguments it will also match when FIRST_NAME is equal to 'A' or 'AN' .
11-24-2014 02:26 PM
The colon after the equals sign shortens the length of the above compare to 3 characters, First name begining with 'AND' will match. In the case above 'A' or 'AN' will not match.