Php/docs/splobjectstorage.gethash
SplObjectStorage::getHash
(PHP 5 >= 5.4.0, PHP 7)
SplObjectStorage::getHash — Calculate a unique identifier for the contained objects
说明
public SplObjectStorage::getHash
( object $object
) : string
This method calculates an identifier for the objects added to an SplObjectStorage object.
The implementation in SplObjectStorage returns the same value as spl_object_hash().
The storage object will never contain more than one object with the same identifier. As such, it can be used to implement a set (a collection of unique values) where the quality of an object being unique is determined by the value returned by this function being unique.
参数
object- The object whose identifier is to be calculated.
返回值
A string with the calculated identifier.
范例
Example #1 SplObjectStorage::getHash() example
<?phpclass OneSpecimenPerClassStorage extends SplObjectStorage { public function getHash($o) { return get_class($o); }}class A {}$s = new OneSpecimenPerClassStorage;$o1 = new stdClass;$o2 = new stdClass;$o3 = new A;$s[$o1] = 1;//$o2 is considered equal to $o1 so the value is replaced$s[$o2] = 2;$s[$o3] = 3;//these are considered equal to the objects before//so they can be used to access the values stored under them$p1 = new stdClass;$p2 = new A;echo $s[$p1], "\n";echo $s[$p2], "\n";?>
以上例程的输出类似于：
2 3
