in reply to Re: Re: (stephen) Hash Tutorial
in thread Hash Tutorial

What you want in your snippet there is a grep() not map() as you're filtering out items not applying transforms to them e.g
shell> perl -le '%a = qw/1 1 2 2 3 3/; %b = qw/2 2 3 3/; \ print grep !$b{$_}, keys %a' 1
Also note that the map() in your snippet is returning a list of three items - a 1 and two empty strings.