serialize将实例转化为字符串, unserialize() 还原已经序列化的对象

//serialize.php
//声明一个类
class dog {
    var $name;
    var $age;
    var $owner;
    function dog($in_name="unnamed",$in_age="0",$in_owner="unknown") {
        $this->name = $in_name;
        $this->age = $in_age;
        $this->owner = $in_owner;
    }
    function getage() {
        return ($this->age * 365);
    }

    function getowner() {
        return ($this->owner);
    }

    function getname() {
        return ($this->name);
    }
}
//实例化这个类
$ourfirstdog = new dog("Rover",12,"Lisa and Graham");
var_dump($ourfirstdog);
//用serialize函数将这个实例转化为一个序列化的字符串
$dogdisc = serialize($ourfirstdog);
print $dogdisc; //$ourfirstdog 已经序列化为字符串 O:3:"dog":3:{s:4:"name";s:5:"Rover";s:3:"age";i:12;s:5:"owner";s:15:"Lisa and Graham";}
print '
';
/*
-----------------------------------------------------------------------
    在这里你可以将字符串 $dogdisc 存储到任何地方如 session,cookie,数据库,php文件
-----------------------------------------------------------------------
*/
//我们在此注销这个类
unset($ourfirstdog);
echo '

---

---

';
/*    还原操作   */
/*
-----------------------------------------------------------------------
    在这里将字符串 $dogdisc 从你存储的地方读出来如 session,cookie,数据库,php文件
-----------------------------------------------------------------------
*/
//我们在这里用 unserialize() 还原已经序列化的对象
$pet = unserialize($dogdisc); //此时的 $pet 已经是前面的 $ourfirstdog 对象了
var_dump($pet);
//获得年龄和名字属性
$old = $pet->getage();
$name = $pet->getname();
//这个类此时无需实例化可以继续使用,而且属性和值都是保持在序列化之前的状态
print "Our first dog is called $name and is $old days old
";
print '
';
?>

object(dog)[1]
  public 'name' =>  'Rover' (length=5)
  public 'age' =>  12
  public 'owner' =>  'Lisa and Graham' (length=15)

O:3:"dog":3:{s:4:"name";s:5:"Rover";s:3:"age";i:12;s:5:"owner";s:15:"Lisa and Graham";}

---

---

object(dog)[1]
  public 'name' =>  'Rover' (length=5)
  public 'age' =>  12
  public 'owner' =>  'Lisa and Graham' (length=15)

Our first dog is called Rover and is 4380 days old