use English; use strict; 
my $key; my $value;
print "HASH WITH DUPLICATES...\n";
my %mapdup =
(
    1  => "one", 2  => "two",  5  => "five",    # English
    1  => "un",  2  => "deux", 5  => "cinq",    # French
    1  => "ein", 2  => "zwei", 5  => "funf",    # German
    1  => "bir", 2  => "iki",  5  => "bes",     # Turkish
    1  => "yi",  2  => "er",   5  => "wu",      # Mandarin 
);
while (($key, $value) = each %mapdup)
{
    print "($key, $value)\n"  if defined $value;
    print "($key, <undef>)\n" if not defined $value;
}   

##</code><code>##

use English; use strict;
my $key; my $value; my $i;
print "\nHASH OF LISTS\n";
my %maplist =
(
    1  => [ ("one", "un", "ein")            ],
    2  => [ ("deux", "er", "two")           ],
    5  => [ ("five", "cinq", "bes", "funf") ],
);
while (($key, $value) = each %maplist)
{
    print "($key, @{$value})\n"  if defined $value;
    print "($key, <undef>)\n" if not defined $value;
}
print "\nHASH OF ARRAYS\n";
my %maparray =
(
    1  => ["one",  "yi"],
    2  => ["zwei", "iki", "two"],
    5  => ["cinq", "five"],
);
print "\n";
foreach my $elem (sort(keys %maparray))
{
    print "$elem: @{$maparray{$elem}}\n";
}
print "\nHASH OF HASHES\n";
my %mapmap =
(
     1 => { english => "one",  french  => "un",   turkish  => "bir"  },
     2 => { french  => "duex", english => "two",  mandarin => "er"   },
     5 => { german  => "funf", french  => "cinq", english  => "five" },
);
print "\n";
foreach my $elem ( sort {$a <=> $b} (keys %mapmap) )
{
    print "$elem: { ";
    foreach my $item (sort keys %{$mapmap{$elem}})
    {
        print "$item=$mapmap{$elem}{$item} ";
    }
    print "}\n";
}