keys are strings never arrays

##</code><code>##

#!/usr/bin/perl -w
use strict;
use warnings;

my %hash;
$hash{'number'}{'even'} = [24, 44, 38, 36];
$hash{'number'}{'odd'} = [23, 43, 37, 35];

foreach my $i(keys %hash){
    print $i;
    foreach my $j(keys %{$hash{$i}}){
        print "\t".$j."\t";
        print join(" ",@{$hash{'number'}{$j}})."\n";
    }
}