Benchmark: PHP Reverse Array while vs. for vs. foreach

When looping through an array in reverse and wondering which was faster while finding nothing on Google, I put this benchmark together.

Function	Time	Comparison
while()	0.921 seconds	(38% faster)
for()	0.916 seconds	(38.4% faster)
for() optimized	0.793 seconds	(46.6% faster)
foreach()	1.486 seconds

Here is the code:

<?php

$test_array = array(0,1,2,3,4,5);

function getmicrotime()
{
  list($usec, $sec) = explode(' ',microtime());
  return ((float)$usec + (float)$sec);
}

$time_start = getmicrotime();
for ($i=0; $i<1000000; $i++)
{
  $j = count($test_array)-1;

  while ($j >= 0)
  {
    $test_array[$j];

    $j--;
  }
}
echo 'while() :: '.number_format(getmicrotime()-$time_start,3).' seconds<br/>';

$time_start = getmicrotime();
for ($i=0; $i<1000000; $i++)
{
  $length = count($test_array)-1;

  for ($j=$length; $j>=0; $j--)
  {
    $test_array[$j];
  }
}
echo 'for() :: '.number_format(getmicrotime()-$time_start,3).' seconds<br/>';

$time_start = getmicrotime();
for ($i=0; $i<1000000; $i++)
{
  for ($j=count($test_array)-1; $j>=0; $j--)
  {
    $test_array[$j];
  }
}
echo 'for() optimized :: '.number_format(getmicrotime()-$time_start,3).' seconds<br/>';

$time_start = getmicrotime();
for ($i=0; $i<1000000; $i++)
{
  $reversed_array = array_reverse($test_array, true);

  foreach ($reversed_array as $key=>$value)
  {
    // Nothing
  }
}
echo 'foreach() :: '.number_format(getmicrotime()-$time_start,3).' seconds<br/>';