run code in 200+ php & hhvm versions
<?php $a=[1,2]; $b=[2,...$a, 1=>3]; var_dump($b);
based on k9n7G

Shows result from various feature-branches currently under review from the php developers. Contact me to have additional branches featured.

Output for branch php-master
array(3) { [0]=> int(2) [1]=> int(3) [2]=> int(2) }

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