public function key() {
		$keys = array_keys($this->data);
		return isset($keys[$this->position]) ? $keys[$this->position] : null;
	}
public function key() {
		$keys = array_keys($this->data);
		return isset($keys[$this->position]) ? $keys[$this->position] : null;
	}
public function key ( ) { $ keys = array_keys ( $ this -> data ) ; return isset ( $ keys [ $ this -> position ] ) ? $ keys [ $ this -> position ] : null ; }
Retrieve the current key. Part of the Iterator interface.

@return null
Retrieve the current key . Part of the Iterator interface .