PHP Object Serialization The Serializable interface



Classes that implement this interface no longer support __sleep() and __wakeup(). The method serialize is called whenever an instance needs to be serialized. This does not invoke __destruct() or has any other side effect unless programmed inside the method. When the data is unserialized the class is known and the appropriate unserialize() method is called as a constructor instead of calling __construct(). If you need to execute the standard constructor you may do so in the method.

Basic usage

class obj implements Serializable {
    private $data;
    public function __construct() {
        $this->data = "My private data";
    public function serialize() {
        return serialize($this->data);
    public function unserialize($data) {
        $this->data = unserialize($data);
    public function getData() {
        return $this->data;

$obj = new obj;
$ser = serialize($obj);

var_dump($ser); // Output: string(38) "C:3:"obj":23:{s:15:"My private data";}"

$newobj = unserialize($ser);

var_dump($newobj->getData()); // Output: string(15) "My private data"