PHP SPL标准库之数据结构对象容器(SplObjectStorage)

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();
}