php - 对象序列化 __sleep

Question

php 手册指出:

It can clean up the object and is supposed to return an array with the names of all variables of that object that should be serialized.

我的理解是，如果有一个类(class)。像这样:

<?php

class Foo {

    public $bar = 'bar';

    public $baz = 'baz';

    public function __sleep() {
        return array('bar');
    }

}

$obj = new Foo();
$serialized = serialize($obj);
$unserialized = unserialize($serialized);

var_dump($unserialized);

?>

它只会序列化对象和属性 $bar?像这样:

object(Foo)[2]
  public 'bar' => string 'bar' (length=3)

但它返回:

object(Foo)[2]
  public 'bar' => string 'bar' (length=3)
  public 'baz' => string 'baz' (length=3)

我理解错了吗？还是我做错了什么？

Answer 1

反序列化创建对象的新实例，并且由于您对类的定义初始化了属性，因此您获得了它的默认值。试试这个:

class Foo {
    public $bar;
    public $baz;
    public function __sleep()
    {
        return array('bar');
    }
}

$obj = new Foo();
$obj->bar = 'bar';
$obj->baz = 'baz';
$serialized = serialize($obj);
$unserialized = unserialize($serialized);
var_dump($unserialized);

编辑:或者，您可以使用 vardump($serialized) 并查看其中没有 baz。