(PHP 5 >= 5.1.0, PHP 7) Check whether the current element is valid

(PHP 5 >= 5.3.0, PHP 7) Get the key of the current element

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

(PHP 5 >= 5.3.0, PHP 7) Constructs a new filesystem iterator

(PHP 5 >= 5.1.0, PHP 7) Gets the current key

(PHP 5 >= 5.1.0, PHP 7) Appends an iterator

(PHP 5 >= 5.2.0, PHP 7) Retrieve the contents of the cache

(PHP 5 >= 5.3.0, PHP 7) Get the handling flags

(PHP 5 >= 5.2.0, PHP 7) Returns an iterator for the current entry.

(PHP 5 >= 5.1.0, PHP 7) Get the current value