3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = [ [1 => 2], [1 => 2], [2 => 1], [3 => 1], ]; $result = []; foreach ($array as $row) { $k = key($row); if (!isset($ref[$k])) { $ref[$k] = 0; $result[][$k] =& $ref[$k]; } $ref[$k] += $row[$k]; } var_export($result);
Output for git.master_jit, git.master
array ( 0 => array ( 1 => 4, ), 1 => array ( 2 => 1, ), 2 => array ( 3 => 1, ), )

This tab shows result from various feature-branches currently under review by the php developers. Contact me to have additional branches featured.

Active branches

Archived branches

Once feature-branches are merged or declined, they are no longer available. Their functionality (when merged) can be viewed from the main output page

preferences:
52.7 ms | 405 KiB | 5 Q