note 53268 deleted from language.references.pass by danbrown

Note Submitter: Andy Morris ---- "jbr at diasparsoftware dot com" spotted something strange when calling call_user_func() where the user function was declared as expecting a reference and seemed to contradict the manual. Actually, the manual says that parameters to call_user_func() aren't passed as references, which I take to mean that if you declare your user function as expecting a parameter by reference, this won't work. In jbr's test code, this doesn't work - so this part isn't a surprise. However, the manual goes on to say that the way out of the problem is to use call_user_func_array() and pass the parameter by reference in an array instead. For example, see this code (from the call_user_func manual page)... <?php function increment(&$var) { $var++; } $a = 0; call_user_func('increment', $a); echo $a; // 0 call_user_func_array('increment', array(&$a)); // You can use this instead echo $a; // 1 // I've added this call to illustrate something strange... call_user_func('increment', &$a); // but look - just adding & works too! echo $a; // 2 ?> The strange thing that "jbr at diasparsoftware dot com" discovered is that you don't actually have to use call_user_func_array() at all, so long as you explicitly specify the variable to be passed by reference when actually calling your function via call_user_func(). Is this just a lucky coincidence? I'm still hunting in the manual to see whether this really is just lucky, or a simpler correct way to do it.