Online PHP editor | refs for HvtZL

@ 2014-09-25T09:00:34Z

<?php

$primes = array();
$found = 0;
for ($x = 2; $x <= 100000; $x++) {
    $xIsPrime = TRUE;
    $sqrtX = sqrt($x);
    foreach ($primes as $prime) if ($prime > $sqrtX || ((!($x % $prime)) && (!$xIsPrime = FALSE))) break;
    if ($xIsPrime) $found++;
}

echo $found;