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__wakeup(), when executing unserialize(), this function will be called first
If __sleep() is white, then __wakeup() It's just black.
So why?
Because:
In contrast, `unserialize()` will check whether there is a `__wakeup()` method. If it exists, the `__wakeup` method will be called first to prepare the resources needed by the object in advance.
Function:
__wakeup() is often used in deserialization operations, such as re-establishing a database connection, or performing other initialization operations.
Still look at the code:
<?php class Person { public $sex; public $name; public $age; public function __construct($name="", $age=25, $sex='男') { $this->name = $name; $this->age = $age; $this->sex = $sex; } /** * @return array */ public function __sleep() { echo "当在类外部使用serialize()时会调用这里的__sleep()方法<br>"; $this->name = base64_encode($this->name); return array('name', 'age'); // 这里必须返回一个数值,里边的元素表示返回的属性名称 } /** * __wakeup */ public function __wakeup() { echo "当在类外部使用unserialize()时会调用这里的__wakeup()方法<br>"; $this->name = 2; $this->sex = '男'; // 这里不需要返回数组 } } $person = new Person('小明'); // 初始赋值 var_dump(serialize($person)); var_dump(unserialize(serialize($person)));
Running result:
当在类外部使用serialize()时会调用这里的__sleep()方法 string(58) "O:6:"Person":2:{s:4:"name";s:8:"5bCP5piO";s:3:"age";i:25;}" 当在类外部使用serialize()时会调用这里的__sleep()方法 当在类外部使用unserialize()时会调用这里的__wakeup()方法 object(Person)#2 (3) { ["sex"]=> string(3) "男" ["name"]=> int(2) ["age"]=> int(25) }
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