- microtime: documentation ( source)
- printf: documentation ( source)
<?php
echo "++i ";
$start = microtime(true);
for ($i = 0; $i < 1000000; ++$i);
$delta_pre = microtime(true) - $start;
printf('%.4F', $delta_pre);
echo PHP_EOL;
echo "i++ ";
$start = microtime(true);
for ($i = 0; $i < 1000000; $i++);
$delpa_post = microtime(true) - $start;
printf('%.4F', $delpa_post);
echo PHP_EOL;
echo PHP_EOL;
printf('%.2F', $delta_pre / $delpa_post * 100);
echo "%", PHP_EOL;