Are php5 function parameters passed as references or as copies?

Question

Are Php function parameters passed as references to object or as copy of object?

It's very clear in C++ but in Php5 I don't know.

Example:

<?php
$dom = new MyDocumentHTMLDom();
myFun($dom);

Is parameter $dom passed as a reference or as a copy?

Answer 1

In PHP5, objects are passed by reference. Well, not exactly in technical way, because it's a copy - but object variables in PHP5 are storing object IDENTIFIER, not the object itself, so essentially it's the same as passing by reference.

More here: http://www.php.net/manual/en/language.oop5.references.php