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

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

(PHP 5 >= 5.1.0, PHP 7) Get children public

(PHP 5 >= 5.1.0, PHP 7) Copy the iterator into an array

(PHP 5 >= 5.1.0, PHP 7) Rewind the file to the first line

(PHP 5 >= 5.0.0, PHP 7) Create a new iterator from an ArrayObject instance

(PHP 5 >= 5.2.0, PHP 7) Sort the entries by keys using a user-defined comparison function

(PHP 5 >= 5.3.0, PHP 7) Unsets the value at the specified $index

(PHP 5 >= 5.2.0, PHP 7) Set the delimiter and enclosure character for CSV

(PHP 5 >= 5.1.0, PHP 7) Checks if the storage contains a specific object