<?php
$max = 10000;
$test = array(1, 2);
// test 1
$start = microtime(true);
for ($z = 0; $z < $max; $z++) {
  if (count($test) == 3) {
    
  }
}
echo '<br>count '.( microtime(true) - $start);
// test 2
$start = microtime(true);
for ($z = 0; $z < $max; $z++) {
  if (sizeof($test) == 3) {
    
  }
}
echo '<br>sizeof '.( microtime(true) - $start);
// test 3
$start = microtime(true);
for ($z = 0; $z < $max; $z++) {
  if (isset($test[2])) {
    
  }
}
echo '<br>isset '.( microtime(true) - $start);

// test 4
$start = microtime(true);
for ($z = 0; $z < $max; $z++) {
  if (count($test) == 2) {
    
  }
}
echo '<br>count '.( microtime(true) - $start);
// test 5
$start = microtime(true);
for ($z = 0; $z < $max; $z++) {
  if (sizeof($test) == 2) {
    
  }
}
echo '<br>sizeof '.( microtime(true) - $start);
// test 6
$start = microtime(true);
for ($z = 0; $z < $max; $z++) {
  if (isset($test[1])) {
    
  }
}
echo '<br>isset '.( microtime(true) - $start);