#!/bin/perl

use strict;
use warnings;


use Benchmark qw(cmpthese);

## benchmark to determine best method
##  of finding common elements in two
##  arrays

my @array1 = ( '0', '1', '2', '3', '5' );
my @array2 = ( '0', '1', '2', '3', '4', '6' );

cmpthese (100000, {
    'using foreach' =>
        sub {
            my @common;

            foreach my $element1 (@array1) {
                foreach my $element2 (@array2) {
                    if ($element1 eq $element2) {
                        push @common, $element1 unless grep { $element1 eq $_ } @common;
                    }
                }
            }
        },
    'using grep' =>
        sub {
            my @common;

            @common =
                grep {
                    my $element1 = $_;
                    ! grep { $element1 == $_ } @array2
                } @array2;
        }
    });