Perl/Perlfaq4-65

1. 두 개의 해쉬에서 고유한 키들을 얻어내기 (How can I get the unique keys from two hashes?)

        %seen = ();
        for $element (keys(%foo), keys(%bar)) {
                $seen{$element}++;
                }
        @uniq = keys %seen;

        @uniq = keys %{{%foo,%bar}};

        %seen = ();
        while (defined ($key = each %foo)) {
                $seen{$key}++;
        }
        while (defined ($key = each %bar)) {
                $seen{$key}++;
        }
        @uniq = keys %seen;