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<?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']));
Output for 8.0.0beta1 - rc2
string(11) "secondfirst" string(11) "firstsecond"
Output for 7.2.0 - 7.2.34, 7.3.0 - 7.3.23, 7.4.0 - 7.4.11, 8.0.0alpha1 - alpha3
string(11) "firstsecond" string(11) "firstsecond"