Performance test

<?php
const ITERATIONS_COUNT = 99999;

$open = '<p style="display: none">';
$close = '</p>';

$time_start = microtime(true);
for ($i = 0; $i < ITERATIONS_COUNT; $i++) {
    echo $open . $i . $close;
}
$timeOne = microtime(true) - $time_start;

$time_start = microtime(true);
for ($i = 0; $i < ITERATIONS_COUNT; $i++):?><p style="display: none"><?=$i?></p><?php endfor;
$timeTwo = microtime(true) - $time_start;
echo $timeOne . '|' . $timeTwo;