Unity入门，这个问题很是不懂

Question

麻烦来个好心人解答一下这是怎么回事，我是按书上打的代码，怎么会错

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class hellowolrd. : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {

    }

    // Update is called once per frame
    void Update()
    {
    void OnGUI()
    {
        GUI.skin.label.fontSize = 100;
        GUI.Label(new Rect(10, 10, Screen.width, Screen.height), "Hello World");
    }
    }
}

Answer 1

首先楼上说的C#本身是支持函数嵌套的，这块从语法上讲没错误，错误应该在于hellowolrd. 后面的这个点，C#是不支持这么定义类名的，去掉就好了