PHP SplObjectStorage使用執行個體_php執行個體

PHP SPL SplObjectStorage是用來儲存一組對象的，特別是當你需要唯一標識對象的時候。
PHP SPL SplObjectStorage類實現了Countable,Iterator,Serializable,ArrayAccess四個介面。可實現統計、迭代、序列化、數組式訪問等功能。

看下面一個簡單的例子：

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); $container = new SplObjectStorage(); //SplObjectStorage::attach 添加對象到Storage中$container->attach($a1);$container->attach($a2);$container->attach($a3); //SplObjectStorage::detach 將對象從Storage中移除$container->detach($a2); //SplObjectStorage::contains用於檢查對象是否存在Storage中var_dump($container->contains($a1)); //truevar_dump($container->contains($a4)); //false //遍曆$container->rewind();while($container->valid()) {  var_dump($container->current());  $container->next();}