#!/usr/bin/perl -w
use Benchmark;
use strict;
use integer;
my %top_hash;

for (my $i = 0; $i < 1000; $i++) {
	$top_hash{$i} = $i;
}

sub e {
	my $total = 0;
	my %hash = %top_hash;

	while (my($k, $v) = each %hash) {
		$total += $v;
		last if $total > 500;
	}
}

sub k {
	my $total = 0;
 	my %hash = %top_hash;
	foreach my $k (keys %hash) {
		my $v = $hash{$k};
		$total += $v;
		last if $total > 500;
	}
}

timethese(500, { 'each' => \&e,
		 'keys' => \&k });

##</code><code>##

Benchmark: timing 500 iterations of each, keys...
	each:  4 wallclock secs ( 3.77 usr +  0.01 sys =  3.78 CPU)
	keys:  5 wallclock secs ( 4.85 usr +  0.00 sys =  4.85 CPU)