SplDoublyLinkedList
PHP Manual

SplDoublyLinkedList::key

(PHP 5 >= 5.3.0)

SplDoublyLinkedList::key — Return current node index

说明

mixed SplDoublyLinkedList::key ( void )

This function returns the current node index

参数

此函数没有参数。

返回值

The current node index.

SplDoublyLinkedList
PHP Manual