C#中foreach原理以及模拟的实现

2019-12-26 12:29:55丽君

   {
       return null;
   }
   else
   {
       return name[index];
   }
      }
  }
  public bool MoveNext()
  {
      ++index;  //每调用此方法就将索引往下+1
      if (index<name.Length)
      {
   return true;
      }
      else
      {
   return false;
      }
  }
  public void Reset()
  {
     index=-1;
  }
}

 

在主方法里面:

 

复制代码 class Program
{
        static void Main(string[] args)
        {
            Person p = new Person();
            //for (int i = 0; i < p.Count; i++)
            //{
            //    Console.WriteLine(p[i]);
            //}
            foreach (string item in p)
            {
                Console.WriteLine(item);
            }
            //实际执行foreach就相当于执行下面几句话:
            Console.WriteLine("==================================================");
            IEnumerator p1 = p.GetEnumerator();
            while (p1.MoveNext())
            {
                string str=(string)p1.Current;
                Console.WriteLine(str);
            }