C#栈

using System;using System.Collections;using System.Collections.Generic;using System.Text;namespace Csharp{    class Program    {        static void Main(string[] args)        {            //栈            var s = new Stack<char>();            s.Push('A');            s.Push('B');            s.Push('C');            s.Push('D');            s.Pop();            s.Push('E');            foreach (var item in s)            {                Console.Write(item);            }                        Console.ReadKey();        }           }  }