Is it possible to overload operators in PHP?

Specifically, I would like to create an Array class and would like to overload the [] operator.

If you are using PHP5 (and you should be), take a look at the SPL ArrayObject classes. The documentation isn't too good, but I think if you extend ArrayObject, you'd have your "fake" array.

EDIT: Here's my quick example; I'm afraid I don't have a valuable use case though:

class a extends ArrayObject {
    public function offsetSet($i, $v) {
        echo 'appending ' . $v;
        parent::offsetSet($i, $v);
    }
}

$a = new a;
$a[] = 1;

Actually, the optimal solution is to implement the four methods of the ArrayAccess interface: http://php.net/manual/en/class.arrayaccess.php

If you would also like to use your object in the context of 'foreach', you'd have to implement the 'Iterator' interface: http://www.php.net/manual/en/class.iterator.php