run code in 300+ PHP versions simultaneously
<?php function foo($b, $a) { return $b . $a; } var_dump(call_user_func_array('foo', ['a' => 'first', 'b' => 'second'])); var_dump(call_user_func_array('foo', ['first', 'second']));

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

Output for branch master
string(11) "secondfirst" string(11) "firstsecond"
Output for branch master_jit
string(11) "secondfirst" string(11) "firstsecond"

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