linq中的分组和排序

一、分组  group 组内成员 by 分组条件 into 组的信息

 class Program
    {
        static void Main(string[] args)
        {
            string[] name = { "张三","张六","刘大","刘晓","刘大脑袋","王大锤"};
            var result = from n in name
                         group n by n[0] into g
                         select g;
            foreach (var g in result)
            {
                Console.WriteLine(g.Key+""+g.Count()+"人");
                foreach (var item in g)
                {
                    Console.WriteLine(item);
                }
            }
        }
    }

二、order by 排序

 class Program
    {
        static void Main(string[] args)
        {
            //降序排序，默认是升序
            List<int> nums = new List<int> { 12,46,55,87,45,12,12,1,2,3};
            //方法1 linq语句+linq方法
            var result = from i in nums
                         orderby i descending
                         select i;
            foreach (var i in result)
            {
                Console.WriteLine(i);
            }
            //linq方法
            var num= nums.OrderByDescending(i => i);
            foreach (var i in num)
            {
                Console.WriteLine(i);
            }

        }
    }