EmptyIterator::key

(PHP 5 >= 5.1.0, PHP 7)

EmptyIterator::keyThe key() method

˵��

public EmptyIterator::key ( void ) : scalar

This function must not be called. It throws an exception upon access.

Warning

��������δ��д�ĵ������в����б�

����

�˺���û�в�����

�����쳣

Throws an Exception if called.

����ֵ

û�з���ֵ��