3v4l.org

run code in 200+ php & hhvm versions
<?php $d = array(3,4,5,6); $a[] = [$d[3],$d[0]]; echo"<pre>"; print_r($a);
based on fORkd
Output for 7.1.25 - 7.4.0alpha2
<pre>Array ( [0] => Array ( [0] => 6 [1] => 3 ) )