1--TEST-- 2call_user_func_array() passes by reference if the array element is referenced, regardless of function signature. 3--FILE-- 4<?php 5 6function by_val($arg) { 7 $arg = 'changed'; 8} 9 10function by_ref(&$arg) { 11 $arg = 'changed'; 12} 13 14echo "------ Calling by_val() with unreferenced argument ------\n"; 15$arg = array('original'); 16call_user_func_array('by_val', $arg); 17var_dump($arg); 18 19echo "------ Calling by_ref() with unreferenced argument ------\n"; 20$arg = array('original'); 21call_user_func_array('by_ref', $arg); 22var_dump($arg); 23 24echo "------ Calling by_val() with referenced argument ------\n"; 25$arg = array('original'); 26$ref = &$arg[0]; 27call_user_func_array('by_val', $arg); 28var_dump($arg); 29 30echo "------ Calling by_ref() with referenced argument ------\n"; 31$arg = array('original'); 32$ref = &$arg[0]; 33call_user_func_array('by_ref', $arg); 34var_dump($arg); 35 36?> 37--EXPECTF-- 38------ Calling by_val() with unreferenced argument ------ 39array(1) { 40 [0]=> 41 string(8) "original" 42} 43------ Calling by_ref() with unreferenced argument ------ 44 45Warning: by_ref(): Argument #1 ($arg) must be passed by reference, value given in %s on line %d 46array(1) { 47 [0]=> 48 string(8) "original" 49} 50------ Calling by_val() with referenced argument ------ 51array(1) { 52 [0]=> 53 &string(8) "original" 54} 55------ Calling by_ref() with referenced argument ------ 56array(1) { 57 [0]=> 58 &string(7) "changed" 59} 60