Online PHP editor | refs for Y2L95

<?php function f($data) { var_dump($data); var_dump(filter_var($data, FILTER_VALIDATE_INT)); echo PHP_EOL; } f(null); f(false); f(0); f("0"); f(1); f("1"); f(array()); f(array(0)); f(array(1)); class ToStringAble { function __toString() { return "0"; } } f(new ToStringAble()); f(new stdclass());