WeakMap
PHP Manual

WeakMap::key

(PECL weakref >= 0.2.0)

WeakMap::keyReturns the current key under iteration.

Description

public object WeakMap::key ( void )

Returns the object serving as key in the map, at the current iterating position.

Parameters

This function has no parameters.

Return Values

The object key currently being iterated.


WeakMap
PHP Manual