C#基础-059 泛型集合List<>与字典Dictionary<,>

来源：互联网发布：svm算法编辑：程序博客网时间：2024/05/17 04:58

 static void Test01()        {            ArrayList list = new ArrayList();            //Add方法的参数类型是object类型 在传递参数的时候整型1会转化成object类型  这样属于装箱操作            list.Add(1);            //如果实现  list[0] + 2  得到正确的结果  要将list[0]转化成int类型  也就是说要进行拆箱操作              Console.WriteLine((int)list[0] + 2);            //泛型集合在声明的时候已经确定了里面的元素类型            List<string> list0 = new List<string>();            //里面的传入的数据类型只能和声明时定义的类型保持一致            //泛型能在编译时，提供强大的类型检查，减少数据类型之间的显示转化、装箱操作和运行时的类型检查。            list0.Add("C#编程之道");            list0.Add("C#从入门到精通");            list0.AddRange(list0);            Console.WriteLine(list0.Count);            bool ret = list0.Contains("C#编程之道");            Console.WriteLine(ret);            int index = list0.IndexOf("C#从入门到精通", 2);            Console.WriteLine(index);            List<int> numList = new List<int>();            numList.Add(1);            numList.Add(2);            numList.Add(5);            numList.Add(1);            numList.Add(2);            numList.Add(2);            numList.Add(4);            List<int> newList = numList.GetRange(0, numList.Count);            index = -1;            //记录查找元素的数量            int count = 0;            while (newList.IndexOf(2) != -1)            {                index = newList.IndexOf(2);                count++;                newList.RemoveAt(index);            }            Console.WriteLine(count);            Console.WriteLine("-------------------------");            foreach (var item in numList)            {                Console.WriteLine(item);            }        }

Dictionary:

 class Book    {        private string name;        private int price;        private string author;        public string Name        {            get            {                return name;            }            set            {                name = value;            }        }        public int Price        {            get            {                return price;            }            set            {                price = value;            }        }        public string Author        {            get            {                return author;            }            set            {                author = value;            }        }        public Book(string name, int price, string author)        {            this.Name = name;            this.Price = price;            this.Author = author;        }        public override string ToString()        {            return string.Format("书名:{0} 价格:{1} 作者:{2}", Name, Price, Author);        }    }

  static void Test01()        {            Dictionary<string, string> dic = new Dictionary<string, string>();            dic.Add("张杰", "高飞");            dic.Add("刘欢", "好汉歌");            //在一个字典中 键是唯一的            //在一个字典中不同的键可以对应相同的值            dic.Add("周杰伦", "青花瓷");            dic.Add("刘英", "青花瓷");            bool key = dic.ContainsKey("周杰伦");            Console.WriteLine(key);            bool value = dic.ContainsValue("好汉歌");            Console.WriteLine(value);            KeyCollection keys = dic.Keys;            //dic.Remove("刘英");            foreach (var item in keys)            {                Console.WriteLine(item);            }        }        static void Test02()        {            Dictionary<string, Book> books = new Dictionary<string, Book>();            books.Add("0000000",new Book("C#编程之道",56,"王垚"));            books.Add("0000001", new Book("C#从入门到精通", 98, "YY"));            books.Add("0000002", new Book("C#从入门到放弃", 2, "亚东"));            foreach (var item in books)            {                Console.WriteLine(item.Key +" " + item.Value.Price);            }        }        static void Test03()        {            SortedDictionary<string, string> dic = new SortedDictionary<string, string>();            dic.Add("张杰", "高飞");            dic.Add("刘欢", "好汉歌");            //在一个字典中 键是唯一的            //在一个字典中不同的键可以对应相同的值            dic.Add("周杰伦", "青花瓷");            dic.Add("刘英", "青花瓷");            dic.Add("asdef", "青花瓷");            dic.Add("asdeh", "青花瓷");            bool key = dic.ContainsKey("周杰伦");            Console.WriteLine(key);            bool value = dic.ContainsValue("好汉歌");            Console.WriteLine(value);            foreach (KeyValuePair<string,string> item in dic)            {                Console.WriteLine(item.Key);            }        }

阅读全文

0 0