Php/docs/class.weakmap

• PHP Manual
• Weakref
• The WeakMap class

(PECL weakref >= 0.2.0)

类摘要

WeakMap implements Countable , ArrayAccess , Iterator {

/* 方法 */

public __construct ( )

public count ( ) : int

public current ( ) : mixed

public key ( ) : object

public next ( ) : void

public offsetExists ( object $object ) : bool

public offsetGet ( object $object ) : mixed

public offsetSet ( object $object , mixed $value ) : void

public offsetUnset ( object $object ) : void

public rewind ( ) : void

public valid ( ) : bool

}

范例

Example #1 Weakmap usage example

<?php$wm = new WeakMap();$o = new StdClass;class A {    public function __destruct() {        echo "Dead!\n";    }}$wm[$o] = new A;var_dump(count($wm));echo "Unsetting..\n";unset($o);echo "Done\n";var_dump(count($wm));

以上例程会输出：

int(1)
Unsetting..
Dead!
Done
int(0)

Table of Contents

• WeakMap::__construct — Constructs a new map
• WeakMap::count — Counts the number of live entries in the map
• WeakMap::current — Returns the current value under iteration
• WeakMap::key — Returns the current key under iteration
• WeakMap::next — Advances to the next map element
• WeakMap::offsetExists — Checks whether a certain object is in the map
• WeakMap::offsetGet — Returns the value pointed to by a certain object
• WeakMap::offsetSet — Updates the map with a new key-value pair
• WeakMap::offsetUnset — Removes an entry from the map
• WeakMap::rewind — Rewinds the iterator to the beginning of the map
• WeakMap::valid — Returns whether the iterator is still on a valid map element