$> perl -M'Data::Dumper' -le '@f=("f1","f2","f3"); my %b; @b{@f}=();print Dumper(\@f); print Dumper(\%b)' $VAR1 = [ 'f1', 'f2', 'f3' ]; $VAR1 = { 'f1' => undef, 'f3' => undef, 'f2' => undef };