Regular Expressions :: replacing data

 1        #
 2        # replace data with the substitution operator: 's'
 3        # 
 4        #    s/regex/replacement/
 5        #
 6
 7        my $string = 'It starts at 9:45am; but it could be 10 a.m. or 11 P.M.';
 8
 9        # We want a consistent format, e.g., "11 AM"
10
11        $string =~ s|(\d)\s*([aApP])\.?[mM]\.?|$1 \U$2m|g;
12
13        print $string;
14
15        # outputs 'It starts at 9:45 AM; but it could be 10 AM or 11 PM'