3v4l.org

run code in 300+ PHP versions simultaneously
<?php function encode($str) { return preg_replace('/(.)\1*/e', 'strlen($0) . $1', $str); } function decode($str) { return preg_replace('/(\d+)(\D)/e', 'str_repeat($2, $1)', $str); } echo encode('WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW'), "\n"; echo decode('12W1B12W3B24W1B14W'), "\n";

preferences:
39.82 ms | 402 KiB | 5 Q