#!/usr/bin/perl

use strict;
use warnings;

my $h1 = {
 one => 1,
 two => 2,
};

my $h2 = {
 three => 3,
 four => 4,
};

my_sub($h1, $h2);

sub my_sub {
 my ($h1, $h2) = @_;
 print "$_ $h1->{$_}\n" for keys %{$h1};
 print "$_ $h2->{$_}\n" for keys %{$h2};
}