3v4l.org

run code in 300+ PHP versions simultaneously
<?php $str = "\n\n\nABC\n\nDEF\nGHI\n\n\nJKL"; preg_match_all('~\n+|.+\n?~', $str, $matches); print_r(array_map(function($i) {return strtr($i, "\n", "#");},$matches[0]));
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 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 - 8.1.31, 8.2.0 - 8.2.27, 8.3.0 - 8.3.15, 8.4.1 - 8.4.2
Array ( [0] => ### [1] => ABC# [2] => # [3] => DEF# [4] => GHI# [5] => ## [6] => JKL )
preferences:
135.92 ms | 408 KiB | 5 Q