PHP SPL SplObjectStorage是用来存储一组对象的，特别是当你需要唯一标识对象的时候。

PHP SPL SplObjectStorage类实现了Countable,Iterator,Serializable,ArrayAccess四个接口。可实现统计、迭代、序列化、数组式访问等功能。

看下面一个简单的例子：

class A { public $i; public function __construct($i) { $this->i = $i; } } $a1 = new A(1); $a2 = new A(2); $a3 = new A(3); $a4 = new A(4); $container = new SplObjectStorage(); //SplObjectStorage::attach 添加对象到Storage中 $container->attach($a1); $container->attach($a2); $container->attach($a3); //SplObjectStorage::detach 将对象从Storage中移除 $container->detach($a2); //SplObjectStorage::contains用于检查对象是否存在Storage中 var_dump($container->contains($a1)); //true var_dump($container->contains($a4)); //false //遍历 $container->rewind(); while($container->valid()) { var_dump($container->current()); $container->next(); }