3v4l.org

run code in 300+ PHP versions simultaneously
<?php $x = array('red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'violet'); foreach ($x as $key => $value) { echo $key.' '.$value."\n"; if (strlen($value) < 6) unset($x[$key]); }
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
0 red 1 orange 2 yellow 3 green 4 blue 5 indigo 6 violet

preferences:
223.34 ms | 405 KiB | 306 Q