The SplObjectStorage class

Introduction

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

The SplObjectStorage class provides a map from objects to data or, by ignoring data, an object set. This dual purpose can be useful in many cases involving the need to uniquely identify objects.

Class synopsis

public addAll(SplObjectStorage $storage): int

#[\Deprecated] 
 public attach(object $object, mixed $info = null): void

#[\Deprecated] 
 public contains(object $object): bool

public count(int $mode = COUNT_NORMAL): int

public current(): object

#[\Deprecated] 
 public detach(object $object): void

public getHash(object $object): string

public getInfo(): mixed

public key(): int

public next(): void

public offsetExists(object $object): bool

public offsetGet(object $object): mixed

public offsetSet(object $object, mixed $info = null): void

public offsetUnset(object $object): void

public removeAll(SplObjectStorage $storage): int

public removeAllExcept(SplObjectStorage $storage): int

public rewind(): void

public seek(int $offset): void

public serialize(): string

public setInfo(mixed $info): void

public unserialize(string $data): void

public valid(): bool

Examples

<?php
// As an object set
$s = new SplObjectStorage();

$o1 = new stdClass;
$o2 = new stdClass;
$o3 = new stdClass;

$s->attach($o1);
$s->attach($o2);

var_dump($s->contains($o1));
var_dump($s->contains($o2));
var_dump($s->contains($o3));

$s->detach($o2);

var_dump($s->contains($o1));
var_dump($s->contains($o2));
var_dump($s->contains($o3));
?>

bool(true)
bool(true)
bool(false)
bool(true)
bool(false)
bool(false)

<?php
// As a map from objects to data
$s = new SplObjectStorage();

$o1 = new stdClass;
$o2 = new stdClass;
$o3 = new stdClass;

$s[$o1] = "data for object 1";
$s[$o2] = array(1,2,3);

if (isset($s[$o2])) {
    var_dump($s[$o2]);
}
?>

array(3) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(3)
}

Changelog

Table of Contents

• SplObjectStorage::addAll — Adds all objects from another storage
• SplObjectStorage::attach — Adds an object in the storage
• SplObjectStorage::contains — Checks if the storage contains a specific object
• SplObjectStorage::count — Returns the number of objects in the storage
• SplObjectStorage::current — Returns the current storage entry
• SplObjectStorage::detach — Removes an object from the storage
• SplObjectStorage::getHash — Calculate a unique identifier for the contained objects
• SplObjectStorage::getInfo — Returns the data associated with the current iterator entry
• SplObjectStorage::key — Returns the index at which the iterator currently is
• SplObjectStorage::next — Move to the next entry
• SplObjectStorage::offsetExists — Checks whether an object exists in the storage
• SplObjectStorage::offsetGet — Returns the data associated with an object
• SplObjectStorage::offsetSet — Associates data to an object in the storage
• SplObjectStorage::offsetUnset — Removes an object from the storage
• SplObjectStorage::removeAll — Removes objects contained in another storage from the current storage
• SplObjectStorage::removeAllExcept — Removes all objects except for those contained in another storage from the current storage
• SplObjectStorage::rewind — Rewind the iterator to the first storage element
• SplObjectStorage::seek — Seeks iterator to a position
• SplObjectStorage::serialize — Serializes the storage
• SplObjectStorage::setInfo — Sets the data associated with the current iterator entry
• SplObjectStorage::unserialize — Unserializes a storage from its string representation
• SplObjectStorage::valid — Returns if the current iterator entry is valid