Question

Unfortunately I cannot provide any code examples, however I will try and create an example.
My question is about Objects and memory allocation in PHP.

If I have an object, lets say:

$object = new Class();

Then I do something like

$object2 = $object;

What is this actualy doing? I know there is a clone function, but thats not what I’m asking about, I’m concerned about whether this is creating another identical object, or if its just assigning a reference to $object.

I strongly understand this to mean that it just creates a reference, but in some case usages of mine, I find that I get another $object created, and I can’t understand why.

Answer 1

If you use the magic method __invoke, you can call an object similar to a function, and it will call that magic method.

class Object{
    function __invoke(){ return "hi"; }
}

$object = new Object;
$object2 = $object();
echo $object2; // echos hi

That means that $object2 is equal to whatever that function returns.

Basically, you are calling a function, but using a variable as it’s name. So:

function test(){ echo "hi"; }
$function_name = "test";
$function_name(); // echos hi.

In this case, you are just calling an object instead.

So, in reference to your question, this is actually not ‘cloning’ at all, unless the __invoke() function looks like this:

function __invoke(){ return this }

In which case, it would be a reference to the same class.