Online PHP editor | refs for 0Z6jd

<?php class parentobj implements Serializable { private $data; protected $extradata; public function __construct() { $this->data = "My private data"; } public function getData() { return $this->data; } public function setData($data) { $this->data = $data; } public function getExtraData(){ $this->extradata = array( 'data1','data2' ); } public function serialize() { return serialize(array( $this->data, $this->extradata, )); } public function unserialize($data) { $orgdata = unserialize($data); $this->data = $orgdata[0]; $this->extradata = $orgdata[1]; } } class childobj extends parentobj { public function __construct() { return parent::__construct(); } public function getExtraData(){ $this->extradata = array( 'datachild1','datachild2' ); } public function serialize() { return serialize($this->extradata); } public function unserialize($data) { $this->extradata = unserialize($data); } } $obj = new childobj(); $s = serialize($obj); echo 'first serialize: '; var_dump($s); $u = unserialize($s); echo 'first unserialize: '; var_dump($u); $u->getExtraData(); echo 'with extradata: '; var_dump($u); $s2 = serialize($u); echo 'second serialize: '; var_dump($s2); $u2 = unserialize($s2); echo 'second unserialize: '; var_dump($u2);