The __set_state Method

The __set_state method is static and is called automatically when using the var_export function on an object. It should return a new instance of the class with restored properties. This method is useful for object serialization and deserialization.

Syntax

phppublic static function __set_state(array $properties): object

Example

Let's create a class and implement the __set_state method in it:

php<?php
class MyClass {
  public $prop1;
  public $prop2;
  
  public function __construct($val1, $val2) {
    $this->prop1 = $val1;
    $this->prop2 = $val2;
  }
  
  public static function __set_state($array) {
    return new self($array['prop1'], $array['prop2']);
  }
}

$obj = new MyClass('a', 'b');
$exported = var_export($obj, true);
eval('$newObj = ' . $exported . ';');

var_dump($newObj);
?>

Code execution result:

phpobject(MyClass)#2 (2) {
  ["prop1"]=> string(1) "a"
  ["prop2"]=> string(1) "b"
}

Example

Using __set_state with private properties:

php<?php
class PrivateClass {
  private $secret;
  
  public function __construct($value) {
    $this->secret = $value;
  }
  
  public static function __set_state($array) {
    $obj = new self($array['secret']);
    return $obj;
  }
}

$privateObj = new PrivateClass('12345');
$exported = var_export($privateObj, true);
eval('$newPrivateObj = ' . $exported . ';');

var_dump($newPrivateObj);
?>

Code execution result:

phpobject(PrivateClass)#2 (1) {
  ["secret":"PrivateClass":private]=> string(5) "12345"
}

See Also