http://www.perlmonks.org?node_id=1010457


in reply to Replacing with comma

use strict; use warnings; use 5.010; my $foo = "1,2,3"; substr($foo, rindex($foo,","), 1, "|"); say $foo; # 1,2|3 $foo = "1|2|3"; substr($foo, rindex($foo,"|"), 1, ","); say $foo; # 1|2,3