3v4l.org

run code in 500+ PHP versions simultaneously
<?php $array = []; // make some array for testing for($i=0; $i < 100; $i++) $array["key$i"] = $i; for($i=0; $i < 1000000; $i++) { reset($array); $firstKey = key($array); }

preferences:
48.55 ms | 2288 KiB | 5 Q