3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = array('red1', 'blue1', 'red2', 'red3', 'blue2' ); $redValues = preg_grep("/^red\d+$/i", $array); $result = array_replace($array, array_combine(array_keys($redValues), array_reverse($redValues))); print_r($result);
Output for 5.5.0 - 5.5.35, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.6 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Array ( [0] => red3 [1] => blue1 [2] => red2 [3] => red1 [4] => blue2 )
preferences:
183.38 ms | 404 KiB | 212 Q