C# 键值对

using System;
using System.Collections.Generic;
namespace _09键值对
{
    class Program
    {
        static void Main(string[] args)
        {
            //Dictionary
            //定义一个键值对集合
            Dictionarystring, string> dictionary = new Dictionarystring, string>();
            //添加键值对数据,键必须唯一,值可重复
            dictionary.Add("1", "张珊");
            dictionary.Add("2", "李四");
            dictionary.Add("3", "王五");
            dictionary.Add("4", "王八");
            //重赋值
            dictionary["3"] = "沈继涵";
 
 
 
            //判断集合中是否含有某一个键ContainsKey()
            if (!dictionary.ContainsKey("5"))
            {
                dictionary.Add("5", "杨过");//不含则加
            }
            else
            {
                dictionary["5"] = "杨过";//含则改
            }
 
            Console.WriteLine(dictionary["5"]);
 
            //用foreach
            //通过键遍历集合
            foreach (string item in dictionary.Keys)
            {
 
                Console.WriteLine("键--{0}   值--{1}", item, dictionary[item]);
            }
 
            //通过键值对遍历集合
            foreach (KeyValuePairstring, string> kv in dictionary)
            {
                Console.WriteLine("键--{0}   值--{1}", kv.Key, kv.Value);
            }
 
            Console.ReadKey();
        }
    }
}