(PHP 5 >= 5.3.0, PHP 7) Sets handling flags

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

(PHP 5 >= 5.0.0, PHP 7) Set value for an offset

(PHP 5 >= 5.3.0, PHP 7) Checks whether the heap is empty.

(PHP 5 >= 5.1.0, PHP 7) Set behaviour flags

(PHP 5 >= 5.1.0, PHP 7) Get inner iterator

(PHP 5 >= 5.3.0, PHP 7) Rewind iterator public

(PHP 5, PHP 7) Access the current key public

(PHP 5 >= 5.1.0, PHP 7) Rewind the iterator

(PHP 5 >= 5.3.0, PHP 7) Sets the mode of iteration