Is there ever a need to use ampersand in front of an object?

object, oop, php, php-internals, reference

Solution

Objects use a different reference mechanism. `&$object` is more a reference of a reference. You can't really compare them both. See Objects and references:

A PHP reference is an alias, which allows two different variables to write to the same value. As of PHP 5, 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.

`&$object` is something else than `$object`. I'll give you an example:

foreach ($objects as $object) {
    if ($cond) {
        $object = new Object(); // This won't affect $objects

    }
}

foreach ($objects as &$object) {
    if ($cond) {
        $object = new Object(); // This will affect $objects

    }
}

I won't answer the question if it makes sense, or if there is a need. These are opinion based questions. You can definitely live without the `&` reference on objects, as you could without objects at all. The existence of two mechanisms is a consequence of PHP's backward compatibility.

Problem

Original source