is_a Checks if the object is of this class or has this class as one of its parents &reftitle.description; boolis_a objectobject stringclass_name boolallow_string&false; Checks if the given object is of this class or has this class as one of its parents. &reftitle.parameters; object The tested object class_name The class name allow_string If this parameter set to &false;, string class name as object is not allowed. This also prevents from calling autoloader if the class doesn't exist. &reftitle.returnvalues; Returns &true; if the object is of this class or has this class as one of its parents, &false; otherwise. &reftitle.changelog; &Version; &Description; 5.3.9 Added allow_string parameter 5.3.0 This function is no longer deprecated, and will therefore no longer throw E_STRICT warnings. 5.0.0 This function became deprecated in favour of the instanceof operator. Calling this function will result in an E_STRICT warning. &reftitle.examples; ]]> ]]> &reftitle.seealso; get_class get_parent_class is_subclass_of