3v4l.org

run code in 300+ PHP versions simultaneously
<?php function getFor($i) { $srt=""; $array = [1,2,3,2,4,1,1,2,3]; while ($arr= current($array)) { if ($arr == '$i') { $srt.= "key=".key($array).'<br />'; } next($array); } } echo getFor(1);
Output for 5.5.0 - 5.5.37, 5.6.0 - 5.6.23, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.19, 8.3.0 - 8.3.7
preferences:
184.3 ms | 404 KiB | 235 Q