(PHP 5 >= 5.1.0, PHP 7) Determines acceptability

(PHP 5 >= 5.1.0, PHP 7) Checks validity of the current element

(PHP 5 >= 5.3.0, PHP 7) Move to previous entry

(PHP 5 >= 5.3.0, PHP 7) Pushes an element at the end of the doubly linked list

(PHP 5 >= 5.0.0, PHP 7) Return current array key

(PHP 5 >= 5.3.0, PHP 7) Compare elements in order to place them correctly in the heap while sifting up.

(PHP 5 >= 5.3.0, PHP 7) Gets the number of attached iterator instances

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

(PHP 5 >= 5.1.0, PHP 7) Gets flags for the SplFileObject

(PHP 5 >= 5.1.2, PHP 7) Gets file type public