C# 键值对

1.初始化一个键值对

1  //初始化定义一个键值对，注意最后的括号
2  Dictionary dic = new Dictionary();

 2.为键值对添加元素

1 //键值对的Add函数
2 dic.Add(2, "zhao");
3 dic.Add(4, "qian");
4 dic.Add(6, "sun");
5 dic.Add(8, "li");

3.键值对的ContainsKey和ContainsValue函数

1 //键值对的ContainsKey和ContainsValue函数
2 Console.WriteLine(dic[4]);
3 Console.WriteLine("键值对是否包含键2：" + dic.ContainsKey(2));
4 Console.WriteLine("键值对是否包含键5：" + dic.ContainsKey(5));
5 Console.WriteLine("键值对是否包含值zhao：" + dic.ContainsValue("zhao"));
6 Console.WriteLine("键值对是否包含值Zhao：" + dic.ContainsValue("Zhao"));

 4.键值对的数量

1 //键值对的数量
2 Console.WriteLine("键值对包含键值数量：" + dic.Count);

5.键值对的keys属性

1 //键值对的keys属性
2 foreach (int item in dic.Keys)
3 {
4     Console.WriteLine("键为：{0}，值为：{1}", item, dic[item]);
5 }

 6.对键值对进行遍历

1 //对键值对进行遍历
2 foreach (KeyValuePair kv in dic)
3 {
4     Console.WriteLine("键为：{0}，值为：{1}", kv.Key, kv.Value);
5 }

 

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
            Dictionary dictionary = new Dictionary();
            //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 (KeyValuePair kv in dictionary)
            {
                Console.WriteLine("键--{0}   值--{1}", kv.Key, kv.Value);
            }
 
            Console.ReadKey();
        }
    }
}