Sort Hash by values. Unlike hash keys, hash values are not guaranteed to be unique. If you sort a hash by only its values, the sort order of two elements with the same value may change when you add or delete other values. To do a stable sort by hash values, do a primary sort by value and a secondary sort by key:

%hash = ( Elliot => Babbage,
          Charles => Babbage,
          Grace => Hopper,
          Herman => Hollerith
        );
@sorted = map { { ($_ => $hash{$_}) } }
              sort { $hash{$a} cmp $hash{$b}
                     or $a cmp $b
                   } keys %hash;
foreach $hashref (@sorted) {
    ($key, $value) = each %$hashref;
    print "$key => $value\n";
}
[download]

Charles => Babbage
Elliot => Babbage
Herman => Hollerith
Grace => Hopper

my %data = (bananas => 1,oranges => 7,apples => 12, mangoes => 3,pears
+ => 8,);
# Using <=> instead of cmp because of the numbers
foreach my $fruit (sort {$data{$a} <=> $data{$b}} keys %data) {
    print $fruit . ": " . $data{$fruit} . "\n";
}
[download]