class User public $name; public $age; 基于这个类编写程序 $User = new User);$User->name = "Kingmax";$User->age = 30; foreach($User as $kev=>$value)echo $key.":".$value ."\n"; 以上例程会输出: name:Kingmax age : 30 如果我要以上例程输出的结果变成 姓名:Kingmax 年龄:30 要求只能改User类的代码，不能改执行部分的代码，请问如何实现? 请贴上你的User类的代码.

class User {
public $name;
public $age;

public function __toString() {
return "姓名:" . $this->name . "\n" . "年龄:" . $this->age;
}
}

$User = new User();
$User->name = "Kingmax";
$User->age = 30;

foreach($User as $key => $value) {
echo $key . ":" . $value . "\n";
}
以上例程输出的结果变成
姓名:Kingmax
年龄:30