Linq in C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WangXuConsole
{
    class Program
    {
        static void Main(string[] args)
        {
            //定义了一个UserInfo的类的list
            List<UserInfo> userInfos = new List<UserInfo>();
            //向list 中添加了四个元素
            userInfos.Add(new UserInfo(){ Id = 0,Name = "张零",CreatedAt = DateTime.Now});
            userInfos.Add(new UserInfo() { Id = 1, Name = "张一", CreatedAt = DateTime.Now.AddDays(1) });
            userInfos.Add(new UserInfo() { Id = 2, Name = "张二", CreatedAt = DateTime.Now.AddDays(-1) });
            userInfos.Add(new UserInfo() { Id = 3, Name = "张三", CreatedAt = DateTime.Now.AddDays(-2) });
            //讲元素的内容输出出来
            foreach (var userInfo in userInfos)
            {
                Console.WriteLine("Id为{0},名字为{1},创建时间为{2}",userInfo.Id,userInfo.Name,userInfo.CreatedAt);
            }
            Console.WriteLine("接下来按照时间排序");
            var list = userInfos.OrderBy(p => p.CreatedAt);
            foreach (var item in list)
            {
                Console.WriteLine("Id为{0},名字为{1},创建时间为{2}", item.Id, item.Name, item.CreatedAt);
            }
            Console.WriteLine("接下来进行过滤,筛选出id>1的元素");
            var list1 = userInfos.Where(p => p.Id > 1);
            foreach (var item in list1)
            {
                Console.WriteLine("Id为{0},名字为{1},创建时间为{2}", item.Id, item.Name, item.CreatedAt);
            }
            Console.Read();
        }
    }

    public class UserInfo
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public DateTime CreatedAt { get; set; }
    }
}