//响应json
    /*$data = [
        'errCode'=>0,
        'errMsg' =>'success',
        'data'   => 'yxh',
    ];
    return response()->json($data);*/

//重定向
    //return redirect('Hello');
    //return redirect('Hello')->with('message','yxh');
    //return redirect()->action('UserController@Hello')->with('message','yxh');
    //return redirect()->route('Hello')->with('message','yxh');

//返回上一个页面
    //return redirect()->back();