Calling closure assigned to object property directly

Question

I would like to be able to call a closure that I assign to an object\'s property directly without reassigning the closure to a variable and then calling it. Is this possible

Answer 1

You can do this by calling __invoke on the closure, since that's the magic method that objects use to behave like functions:

$obj = new stdClass();
$obj->callback = function() {
    print "HelloWorld!";
};
$obj->callback->__invoke();

Of course that won't work if the callback is an array or a string (which can also be valid callbacks in PHP) - just for closures and other objects with __invoke behavior.