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);

preferences:
105.43 ms | 1638 KiB | 5 Q