unity test: アクセス指定子 https://dkrevel.com/makegame-beginner/access/

access-1.cs

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

public class NewBehaviourScript : MonoBehaviour
{
    // Cube の Inspector を見ると、script のところに a だけが表示されている
    public int a;
    internal int b;
    protected int c;
    protected internal int d;
    private int e;

    // Start is called before the first frame update
    void Start()
    {
    }

    // Update is called once per frame
    void Update()
    {
    }
}

access-2.cs

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

public class NewBehaviourScript : MonoBehaviour
{
    public float speed;     // public なので自動的にシリアライズされて、インスペクタで表示される

    // Start is called before the first frame update
    void Start()
    {
    }

    // Update is called once per frame
    void Update()
    {
        // ゲームオブジェクトを回転
        transform.rotation *= Quaternion.Euler(0, speed * Time.deltaTime, 0);
    }
}