3v4l.org

run code in 300+ PHP versions simultaneously
<?php $sample = array('a.col1','a.col2','b.col1','c.col1','c.col2','d.col5'); array_walk($sample, function($v) use (&$r){ $arr = explode('.', $v); $alias = isset($arr[0]) ? $arr[0] : ''; $r[$alias][] = isset($arr[1]) ? $arr[1] : ''; }); extract($r); print_r($a);
Output for 7.1.25 - 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 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
Array ( [0] => col1 [1] => col2 )
preferences:
106.26 ms | 1475 KiB | 4 Q