The SplObjectStorage class

Introduction

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

SplObjectStorage

SplObjectStorage implements Countable , Iterator , Traversable , Serializable , ArrayAccess {

/* Methods */

public void addAll ( SplObjectStorage $storage )

public void attach ( object $object [, mixed $data ] )

public boolean contains ( object $object )

public int count ( void )

public object current ( void )

public void detach ( object $object )

public mixed getInfo ( void )

public int key ( void )

public void next ( void )

public boolean offsetExists ( object $object )

public mixed offsetGet ( object $object )

public void offsetSet ( object $object , mixed $info )

public void offsetUnset ( object $object )

public void removeAll ( SplObjectStorage $storage )

public void rewind ( void )

public string serialize ( void )

public void setInfo ( mixed $data )

public void unserialize ( string $serialized )

public boolean valid ( void )

}

Examples

Example #1 SplObjectStorage as a set


<?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));
?>

The above example will output:

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

Example #2 SplObjectStorage as a map


<?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]);
}
?>

The above example will output:

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

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::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::rewind — Rewind the iterator to the first storage element
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

The SplObjectStorage class

Introduction

Class synopsis

Examples

Table of Contents