数组进行增、删、查、改

class Program    {        private static int[] num = new int[0];//定义一个数组        /// <summary>封装num数字字段        ///封装num数字字段        /// </summary>        public int[] Num        {            get            {                if (num == null)                {                    num = new int[0];                }                return num;            }            set { num = value; }        }        /// <summary> 程序入口处        /// 程序入口处        /// </summary>        /// <param name="args"></param>        static void Main(string[] args)        {            string tian;//选择项            int shu, reshu;            do            {                Random rd = new Random();                int n = rd.Next(0, 1000);                Console.WriteLine("1.显示 2.添加 3.删除 4修改 5.查询 6. 退出");                tian = Console.ReadLine();                switch (tian)                {                    case "1":                        ListArray();                        break;                    case "2":                        AddArray(n);                        break;                    case "3":                        if (Cun() == false)                        {                            Console.WriteLine("数组没有一个值存在！！");                            break;                        }                        Console.WriteLine("请输入删除的数");                        shu = int.Parse(Console.ReadLine());                        MinusArray(shu);                        break;                    case "4":                        if (Cun() == false)                        {                            Console.WriteLine("数组没有一个值存在！！");                            break;                        }                        Console.WriteLine("请输入要修改的数");                        shu = int.Parse(Console.ReadLine());                        Console.WriteLine("请输入修改值");                        reshu = int.Parse(Console.ReadLine());                        AmendArray(shu, reshu);                        break;                    case "5":                        if (Cun() == false)                        {                            Console.WriteLine("数组没有一个值存在！！");                            break;                        }                        Console.WriteLine("请输入要查询的数");                        shu = int.Parse(Console.ReadLine());                        FindArray(shu);                        break;                    default:                        Console.WriteLine("输入错误！！");                        break;                }            } while (tian != "6");        }        /// <summary>添加        /// 添加        /// </summary>        /// <param name="shu">添加的数</param>        public static void AddArray(int shu)        {            int[] newnum = new int[num.Length + 1];            for (int i = 0; i < num.Length; i++)            {                if (shu == num[i])                {                    Console.WriteLine("不能重复添加！！");                    return;                }            }            if (num == null)            {                newnum[0] = shu;            }            else            {                for (int i = 0; i < num.Length; i++)                {                    newnum[i] = num[i];                }                newnum[newnum.Length - 1] = shu;                num = newnum;                Console.WriteLine("添加成功！！");            }        }        /// <summary>删除        /// 删除        /// </summary>        /// <param name="shu"></param>        public static void MinusArray(int shu)        {            int[] newnum = new int[num.Length - 1];            int index = -1;            for (int i = 0; i < num.Length; i++)            {                if (shu == num[i])                {                    index = i;                    break;                }            }            if (index < 0)            {                Console.WriteLine("数组中没有此数值！！");                return;            }            for (int i = 0; i < num.Length; i++)            {                if (i != index)                {                    if (i < index)                    {                        newnum[i] = num[i];                    }                    else                    {                        newnum[i - 1] = num[i];                    }                }            }            num = newnum;            if (index >= 0) { Console.WriteLine("删除成功！！"); }        }        /// <summary>修改        /// 修改        /// </summary>        /// <param name="shu"></param>        public static void AmendArray(int shu, int reshu)        {            int index = -1;            for (int i = 0; i < num.Length; i++)            {                if (shu == num[i])                {                    index = i;                }            }            int index2 = -1;            if (index >= 0)            {                //判断修改的值是否与数组中的元素值有重复                for (int i = 0; i < num.Length; i++)                {                    if (reshu == num[i])                    {                        index2 = i;                    }                }                if (index2 >= 0)                {                    Console.WriteLine("不能修改为数组重复的数");                    return;                }                else                {                    num[index] = reshu;                    Console.WriteLine("修改成功！！");                }            }            else            {                Console.WriteLine("没有此数！！");            }        }        /// <summary>查找数组是否此数据        /// 查找数组是否此数据        /// </summary>        /// <param name="shu"></param>        public static void FindArray(int shu)        {            int index = -1;            for (int i = 0; i < num.Length; i++)            {                if (shu == num[i])                {                    index = i;                }            }            if (index > 0)            {                Console.WriteLine("有此数{0}", shu);            }            else            {                Console.WriteLine("没有此数！！");            }        }        /// <summary>显示数组清单        /// 显示数组清单        /// </summary>        public static void ListArray()        {            if (num == null || num.Length == 0)            {                Console.WriteLine("数组没有一个值存在！！");                return;            }            else            {                for (int i = 0; i < num.Length; i++)                {                    Console.WriteLine(num[i]);                }            }        }        /// <summary>判断数组是否为空或者数组长度为0        /// 判断数组是否为空或者数组长度为0        /// </summary>        /// <returns></returns>        public static bool Cun()        {            bool bl = true;            if (num == null || num.Length == 0)            {                bl = false;            }            return bl;        }    }