my $dupes = {}; for my $k (qw/RB TE WR/) { for my $n (qw/1 2 3 4 5/) { $n = $my_data->{$k}{$v}; return 'DUPLICATE FOUND' if exists($dupes->{$n}); $dupes->{$n} = 1; // DON'T CARE ANY VALUE WILL DO } } return 'NO DUPLICATES';