<?php 

   class User 
   { 
       public $name; 
       public $id; 

       function __construct() 
       { 
           //give user a unique ID 赋予一个不同的ID 
           $this->id = uniqid(); 
       } 

       function __sleep() 
       { 
           //do not serialize this->id 不串行化id   
           return(array("name")); 
       } 

       function __wakeup() 
       { 
           //give user a unique ID 
           $this->id = uniqid(); 
       } 
   } 

   //create object 建立一个对象 
   $u = new User; 
   $u->name = "Leon"; 

   //serialize it 串行化 注意不串行化id属性,id的值被抛弃 
   $s = serialize($u); 

   //unserialize it 反串行化 id被重新赋值 
   $u2 = unserialize($s); 

   //$u and $u2 have different IDs $u和$u2有不同的ID 
   print_r($u); 
   print_r($u2); 
?>