is_a Returns &true; if the object is of this class or has this class as one of its parents boolis_a objectobject stringclass_name This function returns &true; if the object is of this class or has this class as one of its parents, &false; otherwise. ]]> The is_a function is deprecated as of PHP 5 in favor of the instanceof type operator. In the above example we could use the following in PHP 5: ]]> See also get_class, get_parent_class, and is_subclass_of.