C#中const和readonly的用法比较

namespace ReadonlyDemo
{
  /// <summary>
  /// 创建一个旅店类
  /// </summary>
  class Hotel
  {
    public readonly int roomNum; //表示房间总数
    public int guestNun;     //表示已入住房间数
    public Hotel(int roomNumValue) { //构造函数
      roomNum = roomNumValue;
    } 
    public bool isFull()
    {
      if(guestNun >= roomNum)
      {
        return true;
      }
      else
      {
        return false;
      }
    }
    //一个旅客入住
    public void LodgeIn()
    {
      if (isFull())
      {
        Console.WriteLine("房间满了");
      }
      else
      {
        guestNun++;
        Console.WriteLine("入住成功");
      }
    }
  }
  class Program
  {
    static void Main(string[] args)
    {
      Console.WriteLine("---------HOT1旅店----------");
      Hotel hot1 = new Hotel(6); //hot1旅店有6个房间
      for (int i = 0; i < 7; i++)
      {
        hot1.LodgeIn(); //入住客人
      }
      Console.WriteLine("HOT1旅店房间总数:{0}", hot1.roomNum);
      Console.WriteLine("HOT1旅店已经入住：{0}人", hot1.guestNun);
      Console.WriteLine("---------Tel1旅店----------");
      Hotel tel1 = new Hotel(5); //Tel1旅店有10个房间
      for (int i = 0; i < 3; i++)
      {
        tel1.LodgeIn(); //入住客人
      }
      Console.WriteLine("Tel1旅店房间总数:{0}", tel1.roomNum);
      Console.WriteLine("Tel1旅店已经入住：{0}人", tel1.guestNun);
      Console.ReadLine();
    }
  }
}