Are PHP5 objects passed by reference?

Question

I can\'t seem to get any consistent info on this. Different sources appear to say different things and the venerable php.net itself (appears) not to explicitly stat

Answer 1

Short answer is yes. From Objects and references:

One of the key-points of PHP5 OOP that is often mentioned is that "objects are passed by references by default". This is not completely true. This section rectifies that general thought using some examples.

A PHP reference is an alias, which allows two different variables to write to the same value. As of PHP5, an object variable doesn't contain the object itself as value anymore. It only contains an object identifier which allows object accessors to find the actual object. When an object is sent by argument, returned or assigned to another variable, the different variables are not aliases: they hold a copy of the identifier, which points to the same object.

What matters is that, in the case that worries you, you'll never be making a copy of an object unless you explicitly use the clone keyword in the function call. Whether it's an alias or an identifier doesn't change this fact.