note 108687 modified in class.arrayobject by danbrown

From:	danbrown@php.net	Date:	Thu, 17 May 2012 18:18:34 +0000
Subject:	note 108687 modified in class.arrayobject by danbrown
References:	1	Groups:	php.notes
Request:	Send a blank email to php-notes+get-188041@lists.php.net to get a copy of this message

Please note, that there's another potential "gotcha" in using ArrayObject like regular array. Objects are reference types and arrays are value types. Consider following piece of code:
<?php

class MyArrayObject extends ArrayObject
{
	protected $data = array();
	public function offsetGet($name) {
		return $this->data[$name];
	}
	public function offsetSet($name, $value) {
		$this->data[$name] = $value;
	}
	public function offsetExists($name) {
		return isset($this->data[$name]);
	}
	public function offsetUnset($name) {
		unset($this->data[$name]);
	}
}

function my_array_modify($data) { //note - not reference &$data
	$data['b'] = 2;
}

$regularArray = array();
$arrayObject = new MyArrayObject();

$regularArray['a'] = 1;
$arrayObject['a'] = 1;
my_array_modify($regularArray);
my_array_modify($arrayObject);
var_dump($regularArray['b']); // PHP Notice: Undefined index: b
var_dump($arrayObject['b']); // int(2)
?> --was-- Please note, that there's another potential "gotcha" in using ArrayObject like regular array. Objects are reference types and arrays are value types. Consider following piece of code: <?php class MyArrayObject extends ArrayObject { protected $data = array(); public function offsetGet($name) { return $this->data[$name]; } public function offsetSet($name, $value) { $this->data[$name] = $value; } public function offsetExists($name) { return isset($this->data[$name]); } public function offsetUnset($name) { unset($this->data[$name]); } } function my_array_modify($data) { //note - not reference &$data $data['b'] = 2; } $regularArray = array(); $arrayObject = new MyArrayObject(); $regularArray['a'] = 1; $arrayObject['a'] = 1; my_array_modify($regularArray); my_array_modify($arrayObject); var_dump($regularArray['b']); // PHP Notice: Undefined index: b var_dump($arrayObject['b']); // int(2) http://php.net/manual/en/class.arrayobject.php