(null) type casting is not authorized in php. See http://php.net/manual/fr/language.types.type-juggling.php http://php.net/manual/fr/language.types.type-jugglin

(null) type casting is not authorized in php. See http://php.net/manual/fr/language.types.type-juggling.php http://php.net/manual/fr/language.types.type-juggling.php for information about type juggling. And what do you think should happen in the second case? It looks normal to me.