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

# the program
my %hash = (
        'one' => [1],
        'two' => [2,2],
        'three' => [3,3,3],
);

print "$hash{one}[0]\n";
print "$hash{two}[0]\n";
print "$hash{three}[0]\n";

while (my ($key, $aref) = each %hash) {
	# dereference array_reference
	# (and the @$aref array is in scalar context)
	printf "key=%s size=%d\n", $key, @$aref;
}


##</code><code>##

1
2
3
key=three size=3
key=one size=1
key=two size=2