use strict;
use warnings;

my %hash;

$hash{01} = 'one';
$hash{07} = 'seven';
$hash{010} = 'eight';
$hash{10} = 'ten';
$hash{'01'} = "'one'";
$hash{'07'} = "'seven'";
$hash{'010'} = "'eight'";
$hash{'10'} = "'ten'";

print "$_ => $hash{$_}\n" for sort keys %hash;

##</code><code>##

01 => 'one'
010 => 'eight'
07 => 'seven'
1 => one
10 => 'ten'
7 => seven
8 => eight