class User

{

    private $name,$regTime,$money;

    public function __construct($name, $regTime)

    {

        $this->name = $name;

        $this->regTime = $regTime;

    }

    public function setMoney($money)

    {

        $this->money = $money;

    }

    public function __toString()

    {

        return "{$this->name} :  {$this->regTime} :  {$this->money}";

    }

}

class UserIterator implements Iterator

{

    private $users = array();

    private $valid = false;

    public function __construct()

    {

        try{

            $sql = "SELECT * FROM yx_users";

            $pdo = new PDO('mysql:host=localhost;dbname=db_zuiyouxin', 'root', 'root');

            $res = $pdo->query($sql);

            foreach ($res as $row) {

                $user = new User($row['name'], $row['created_at']);

                $user->setMoney($row['money']);

                $this->users[$row['id']] = $user;

            }

            $pdo = null;

        } catch (Exception $e) {

            die('Error:' . $e->getMessage());

        }

    }

    public function current()

    {

        return current($this->users);

    }

    public function next()

    {

        $this->valid = (next($this->users) === false) ? false : true;

    }

    public function key()

    {

        return key($this->users);

    }

    public function valid()

    {

        return $this->valid;

    }

    public function rewind()

    {

        $this->valid = (reset($this->users) === false) ? false : true;

    }

}

$users = new UserIterator();

foreach ($users as $key => $val) {

    echo $key;

    echo $val;

    echo "<br>";

}