(PHP 5 >= 5.3.0, PHP 7)
SplObjectStorage::offsetExists — Checks whether an object exists in the storage
$object
) : boolChecks whether an object exists in the storage.
Note:
SplObjectStorage::offsetExists() is an alias of SplObjectStorage::contains().
Returns TRUE if the object exists in the storage,
and FALSE otherwise.
Example #1 SplObjectStorage::offsetExists() example
<?php
$s = new SplObjectStorage;
$o1 = new StdClass;
$o2 = new StdClass;
$s->attach($o1);
var_dump($s->offsetExists($o1)); // Similar to isset($s[$o1])
var_dump($s->offsetExists($o2)); // Similar to isset($s[$o2])
?>
以上例程的输出类似于：
bool(true) bool(false)