\n"; $time1 = microtime(true); echo preg_replace ("/fox/", "cat", $string1) . "
\n"; $time2 = microtime(true); echo "str_replace duration (ms): " . number_format($time1 - $time, 8, '.', '') . "
\n"; echo "preg_replace duration (ms): " . number_format($time2 - $time1, 8, '.', '') . "
\n"; ?>