值类型与引用类型

using System;
using System.Collections.Generic;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int a = 444;
            //New一个列表
            List<int> ll = new List<int>();
            //初始化列表数据，以便测试
            for (int i = 6; i >0; i--)
            {
                ll.Add(i);
            }
            //把a添加到列表最后
            ll.Add(a);
            //输出
            Console.WriteLine("（改变a的值前）a=" + a);
            Console.Write("（改变a的值前）ll列表：");
            foreach (int i in ll)
                Console.Write(i.ToString() + ",");
            Console.WriteLine();
            //改变a的值
            a = 2;
            //输出
            Console.WriteLine("（改变a的值后）a=" + a);
            Console.Write("（改变a的值后）ll列表：");
            foreach (int i in ll)
                Console.Write(i.ToString() + ",");
            Console.WriteLine();

            List<int> kk = new List<int>();
            kk = ll;
            kk.Add(777);

            Console.Write("（给kk列表添加一个值后）ll列表：");
            foreach (int i in ll)
                Console.Write(i.ToString() + ",");
            Console.WriteLine();
            Console.Write("（给kk列表添加一个值后）kk列表：");
            foreach (int i in kk)
                Console.Write(i.ToString() + ",");
            Console.WriteLine();
            kk.Sort();
            Console.Write("（kk列表排序后）ll列表：");
            foreach (int i in ll)
                Console.Write(i.ToString() + ",");
            Console.WriteLine();
            Console.Write("（kk列表排序后）kk列表：");
            foreach (int i in kk)
                Console.Write(i.ToString() + ",");
            Console.WriteLine();
            Console.ReadKey();
        }
    }
}