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

my @array = ("world", "today", "is nice");
my %hash = ( 0 => "Hello",
	     1 => "world",
	     2 => "today",
	     3 => "is" ,
	     4 => "nice" );

my @hashValues = values %hash;

print Dumper \@hashValues;

use List::Compare;

my $lc = List::Compare->new(\@hashValues, \@array);

my @intersection = $lc->get_intersection;
my @union = $lc->get_union;

print Dumper \@intersection;

__END__

Monks$ perl test.pl
$VAR1 = [
          'nice',
          'Hello',
          'today',
          'world',
          'is'
        ];
$VAR1 = [
          'today',
          'world'
        ];

##</code><code>##

my @new_array;
while (my ($key, $value) = each %hash) {
    for (@array) {push @new_array, $key if ($value eq $_);}
}

__END__

$VAR1 = [
          '2',
          '1'
        ];

##</code><code>##

my @new_array_sorted = sort @new_array;

print Dumper \@new_array_sorted;

__END__

$VAR1 = [
          '1',
          '2'
        ];

##</code><code>##

my @new_array;
while (my ($key, $value) = each %hash) {
        push @new_array, $key if (grep { /^$value$/ } @array);
}

__END__

$VAR1 = [
          '2',
          '1'
        ];

##</code><code>##

my @new_array;
while (my ($key, $value) = each %hash) {
    map { if($value eq $_) { push @new_array, $key } } @array;
}

__END__

$VAR1 = [
          '2',
          '1'
        ];

##</code><code>##

no if $] >= 5.018, "experimental::smartmatch"; #disable warnings
while (my ($key, $value) = each %hash) {
       push @new_array, $key if ($value ~~ @array);
   }

__END__

$VAR1 = [
          '2',
          '1'
        ];

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw( timethese cmpthese ) ;
no if $] >= 5.018, warnings => "experimental::smartmatch";

my @array = ("world", "today", "is nice");
my %hash = ( 0 => "Hello",
	     1 => "world",
	     2 => "today",
	     3 => "is" ,
	     4 => "nice" );

my @new_array;
my $results = timethese(1000000000, { 'map' => benchmarkMap(),
				      'grep' => benchmarkGrep(),
				      'foreach' => benchmarkForeach(),
				      'smartmatch' => benchmarkSmartMatch(), },
			'none');
cmpthese( $results ) ;

sub benchmarkSmartMatch {
    while (my ($key, $value) = each %hash) {
        push @new_array, $key if ($value ~~ @array);
    }
}

sub benchmarkGrep {
    while (my ($key, $value) = each %hash) {
        push @new_array, $key if (grep { /^$value$/ } @array);
    }
}

sub benchmarkForeach {
    while (my ($key, $value) = each %hash) {
	for (@array) {push @new_array, $key if ($value eq $_);}
    }
}

sub benchmarkMap {
    while (my ($key, $value) = each %hash) {
    map { if($value eq $_) { push @new_array, $key } } @array;
    }
}

__END__

Monks$ perl test.pl
                  Rate    foreach smartmatch       grep        map
foreach     76569678/s         --       -30%       -59%       -64%
smartmatch 109170306/s        43%         --       -42%       -49%
grep       187969925/s       145%        72%         --       -13%
map        215053763/s       181%        97%        14%         --