php魔术方法，__sleep,__wakeup使用

<?php
class Person
{
    private $name, $age, $sex, $info;

    public function __construct( $name, $age, $sex )
    {
        $this->name = $name;
        $this->age  = $age;
        $this->sex  = $sex;
        $this->info = sprintf("prepared by construct magic functionname: %s age: %d sex: %s",
            $this->name, $this->age, $this->sex);
    }

    public function getInfo()
    {
        echo $this->info . PHP_EOL;
    }
    /**
     * serialize前调用 用于删选需要被序列化存储的成员变量
     * @return array [description]
     */
    public function __sleep()
    {
        echo __METHOD__ . PHP_EOL;
        //序列化时只会存储 name age sex, info 不会被序列化
        return ['name', 'age', 'sex'];
    }
    /**
     * unserialize前调用 用于预先准备对象资源
     */
    public function __wakeup()
    {
        echo __METHOD__ . PHP_EOL;
        $this->info = sprintf("prepared by wakeup magic function name: %s age: %d sex: %s",
            $this->name, $this->age, $this->sex);
    }
}

$boy = new Person( 'sallency', 25, 'male' );
//构造函数组装的 $info
$boy->getInfo();
echo '</br>';
//序列化时并不会存储 $info 属性
$temp = serialize($boy);
echo $temp . PHP_EOL;
echo '</br>';
//反序列化时会调用 __wakeup() 函数
$boy = unserialize($temp);
//__wakeup() 组装的 $info
$boy->getInfo();