dedupe with a haSh in perl

dedupe.pl

#!/usr/bin/perl

use strict;
use warnings;

my @values = qw( a b c d a b c d a b c d);

my %dedupe_hash;

foreach my $value (@values) {
  $dedupe_hash{$value}++;
}

foreach my $key (keys %dedupe_hash) {
  my $value = $dedupe_hash{$value};
  print "key $key has value $value\n";
}