Iterator::current
Iterator::next
Iterator
PHP Manual

# Iterator::key

(PHP 5 >= 5.0.0)

Iterator::key — Return the key of the current element

### Description

abstract public scalar Iterator::key ( void )

Returns the key of the current element.

### Parameters

This function has no parameters.

### Return Values

Returns scalar on success, or `NULL` on failure.

### Errors/Exceptions

Issues `E_NOTICE` on failure.

Iterator::current
Iterator::next
Iterator
PHP Manual