C#应用 - 01.怎么求两个List集合的交并差集

1. 求交并差集主要利用了查询表达式LINQ的扩展方法。

using System;
using System.Collections.Generic;
using System.Linq;

namespace _01
{
    
    
    class Program
    {
    
    
        static void Main(string[] args)
        {
    
    
            List<object> list1 = new List<object>() {
    
     1, 'a', "b" };
            List<object> list2 = new List<object>() {
    
     2, 'a', "b" };
            List<object> list3 = null;

            Console.WriteLine("list1和list2共有的元素：");
            list3 = Test.GetIntersect(list1, list2);
            foreach (var item in list3)
            {
    
    
                Console.Write($"{
      
      item}\t");
            }
            Console.WriteLine();
            Console.WriteLine();

            Console.WriteLine("list1和list2所有的元素：");
            list3 = Test.GetUnion(list1, list2);
            foreach (var item in list3)
            {
    
    
                Console.Write($"{
      
      item}\t");
            }
            Console.WriteLine();
            Console.WriteLine();

            Console.WriteLine("list1比list2多的元素：");
            list3 = Test.GetExcept(list1, list2);
            foreach (var item in list3)
            {
    
    
                Console.Write($"{
      
      item}\t");
            }
            Console.WriteLine();
            Console.WriteLine();

            Console.WriteLine("list2比list1多的元素：");
            list3 = Test.GetExcept(list2, list1);
            foreach (var item in list3)
            {
    
    
                Console.Write($"{
      
      item}\t");
            }
            Console.WriteLine();
            Console.WriteLine();
        }
    }

    class Test
    {
    
    
        /// <summary>
        /// 获取交集
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="list1"></param>
        /// <param name="list2"></param>
        /// <returns></returns>
        public static List<T> GetIntersect<T>(List<T> list1, List<T> list2)
        {
    
    
            return list1.Intersect<T>(list2).ToList();
        }

        /// <summary>
        /// 获取并集
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="list1"></param>
        /// <param name="list2"></param>
        /// <returns></returns>
        public static List<T> GetUnion<T>(List<T> list1, List<T> list2)
        {
    
    
            return list1.Union<T>(list2).ToList();
        }

        /// <summary>
        /// 获取差集
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="list1"></param>
        /// <param name="list2"></param>
        /// <returns></returns>
        public static List<T> GetExcept<T>(List<T> list1, List<T> list2)
        {
    
    
            return list1.Except<T>(list2).ToList();
        }
    }
}