JSON编码格式错误

Question

对不起那些问这个简单问题的人，但我陷入了困境。

我有一个来自webservice的GET方法来检索用户数据。

所以我现在有这样的json输出：

{
    error: false
    users: [2]
       0:  {
          user_id: 44
          email: "asdasd1212@gmail.comnmmm"
          name: "rendyyyyyyy"
          phone: "1212121"
          picture: "hahaha.jpg"
          status: "Actived"
          created_at: "2014-12-27 10:48:10"
    }
    -1:  {
        user_id: 45
        email: "asdas1212151@gmail.comnmmm"
        name: "rendyyyyyyy"
        phone: "1212121"
        picture: "hahaha.jpg"
        status: "Actived"
        created_at: "2014-12-27 10:48:15"
    }
}

我使用以下代码获得了该输出：

$app->get('/admin/list/user', 'authenticate', function() 
{ 
            global $user_id;
            $response = array();


            // fetching all users
            $userDB = new AdminController(MySqlDb::getInstance()->connect());
            $users = $userDB->getAllUsers();

            $response["error"] = false;
            $response["users"] = array();

            foreach ($users as $user) {
                $tmp = array();
                $tmp['user_id'] = $user->getUserId();
                $tmp["email"] = $user->getEmail();
                $tmp["name"] = $user->getName();
                $tmp["phone"] = $user->getPhone();
                $tmp["picture"] = $user->getPicture();
                $tmp["status"] = $user->getStatus();
                $tmp["created_at"] = $user->getCreatedAt();
                array_push($response["users"], $tmp);
            }

            echoRespnse(200, $response);
});


function echoRespnse($status_code, $response) 
{
    $app = \Slim\Slim::getInstance();
    // Http response code
    $app->status($status_code);

    // setting response content type to json
    $app->contentType('application/json');

    echo json_encode($response);
}

我不知道为什么我的JSON输出会出错。 我想要的就是获得这样的JSON输出：

     {
        error: false
        users: [
             {
              user_id: 44
              email: "asdasd1212@gmail.comnmmm"
              name: "rendyyyyyyy"
              phone: "1212121"
              picture: "hahaha.jpg"
              status: "Actived"
              created_at: "2014-12-27 10:48:10"
             },
           {
            user_id: 45
            email: "asdas1212151@gmail.comnmmm"
            name: "rendyyyyyyy"
            phone: "1212121"
            picture: "hahaha.jpg"
            status: "Actived"
            created_at: "2014-12-27 10:48:15"
           }
       ]
    }