<?php

declare (strict_types = 1);

namespace app\controller;

use app\BaseController;

use think\facade\Db;

class Index extends BaseController

{

    public function index()

    {

        $this->hello((int) $_GET['a']);

        $a = Db::name('user')->where('id', 1)->find();

        return json($a);

    }

    public function hello(string $name = 'ThinkPHP6')

    {

        return 'hello,' . $name;

    }

}

Argument 1 passed to app\controller\Index::hello() must be of the type string, int given, called in /www/wwwroot/test/tp6/app/controller/Index.php on line 12