c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le "my %data; my @header = qw(fee fie foe fum); ;; $data{@header} = (); dd \%data; ;; @data{@header} = (); dd \%data; " { 4 => undef } { 4 => undef, fee => undef, fie => undef, foe => undef, fum => undef }