#!/usr/bin/perl -w
use strict;
use Data::Dumper;

my @data = ( qw/ 2 3 3 3 5 7 8 12 32 44 55 12 3 23 43 33 1 4 25 43 42 1 4 5 3 3 3 /);

my $mode = mode( { 'NUMBERS' => \@data } ); # I quote hash keys so I don't 
                                            # mistake them for constants
                                            # and use them as barewords.
print "Mode : $mode\n";

sub mode {
      my %count = (); 
      my %opt = %{ shift @_ };
      for ( @{ $opt{'NUMBERS'} } ) {  # no need to sort the array here
          $count{ $_ }++;
      }   
      my @key = sort{ $count{$b} <=> $count{$a} } keys %count;
      return $key[0];
}

__END__