#! /usr/bin/perl
use strict;
use warnings;
use feature 'say';
# use Benchmark qw(:all) ; # WindowsOS
use Benchmark::Forking qw( timethese cmpthese ); # UnixOS

sub for_loop {
    for my $iloop (0 .. 10){
	say $iloop;
    }
    return;
}

sub while_loop {
    my @numbers = qw( 1 2 3 4 5 6 7 8 9 10 );
    while (defined(my $int = shift @numbers)) {
	say $int;
    }
    return;
}

my $results = timethese(1000000, { While => \&while_loop,
				   ForEach => \&for_loop, }, 'none');
cmpthese( $results );

__END__

$ perl test.pl
        s/iter   While ForEach
While     2.32      --    -14%
ForEach   1.98     17%      --