3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = [1,2,3,2,4,1,1,2,3]; while ($arr= current($array)) { if ($arr == '2') { echo "key=".key($array).'<br />'; } next($array); }

preferences:
27.69 ms | 402 KiB | 5 Q