(PHP 5 >= 5.1.0, PHP 7, PHP 8)
SplObjectStorage::contains — Checks if the storage contains a specific object
$object): boolChecks if the storage contains the object provided.
objectThe object to look for.
Returns true if the object is in the storage, false otherwise.
示例 #1 SplObjectStorage::contains() example
<?php
$o1 = new stdClass;
$o2 = new stdClass;
$s = new SplObjectStorage();
$s[$o1] = "hello";
var_dump($s->contains($o1));
var_dump($s->contains($o2));
?>以上示例的输出类似于：
bool(true) bool(false)