PHP Object Serialization
Serialize / Unserialize
serialize() returns a string containing a byte-stream representation of any value that can be stored in PHP. unserialize() can use this string to recreate the original variable values.
To serialize an object
serialize($object);
To Unserialize an object
unserialize($object)
Example
$array = array();
$array["a"] = "Foo";
$array["b"] = "Bar";
$array["c"] = "Baz";
$array["d"] = "Wom";
$serializedArray = serialize($array);
echo $serializedArray;
Output
a:4:{s:1:"a";s:3:"Foo";s:1:"b";s:3:"Bar";s:1:"c";s:3:"Baz";s:1:"d";s:3:"Wom";}
The Serializable interface
Introduction
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"