gistfile1.txt

function doSomethingRef(&$o) {
    $o = null;
}
function doSomething($o) {
    $o = null;
}

$object = new stdClass;
// passed by reference
doSomethingRef($object); // $object is now null
// passed by handler (usual case)
doSomething($object); // $object is still a stdClass

That's a little bit confusing, isn't it? Shouldn't it be more like:

$object = new stdClass;
// passed by reference
doSomethingRef($object); // $object is now null

$object = new stdClass;
// passed by handler (usual case)
doSomething($object); // $object is still a stdClass

You're right, it wasn't thought as running code. :)