(PHP 5 >= 5.2.0, PHP 7) Get flags used public

(PHP 5 >= 5.2.0, PHP 7) The offsetSet purpose

(PHP 5, PHP 7) Returns the inner iterator public

(PHP 5, PHP 7) Move the iterator forward public

(PHP 5, PHP 7) Check whether the current element is valid

(PHP 5 >= 5.2.0, PHP 7) The offsetGet purpose

(PHP 5 >= 5.2.0, PHP 7) The offsetExists purpose