thinkphp5判断跳转

<?php
namespace app\test\controller;
use think\Controller;

class YangZheWei extends Controller
{
    protected $flag = false;

    public function index()
    {
        if($this -> flag){
          $this->success('注册成功!', 'https://www.xkwo.com/');
        }else{
             $this -> error('失败');
        }
        return '333<br>';
    }
}

?>