C# 根据首字母排序单词的雏形示例

原文档地址：https://www.veryhuo.com/down/html/26615.html

class Program
    {
        public class Student //声明一个Student类 
        {
            public string First { get; set; }  //定义自动属性First表示First Name
            public string Last { get; set; }   //定义自动属性Last表示Last Name
            public int ID { get; set; }        //定义自动属性表示学生ID号
        }

        public static List<Student> GetStudents()
        {
            // 定义集合GetStudents作为数据源.
            List<Student> students = new List<Student>
        {
           new Student {First="Svetlana", Last="Omelchenko", ID=111},//学生信息
           new Student {First="Claire", Last="O'Donnell", ID=112},
           new Student {First="Sven", Last="Mortensen", ID=113},
           new Student {First="Cesar", Last="Garcia", ID=114}//,
           //new Student {First="Debra", Last="Garcia", ID=115} 
        };

            return students;

        }
        static void Main(string[] args)
        {
            // 创建LINQ查询数据源 students
            List<Student> students = GetStudents();

            // 创建LINQ查询
            IEnumerable<Student> sortedStudents =
                from student in students
                orderby student.Last ascending, student.First ascending //先按Lastname排序，再按First排序
                select student;

            // 执行查询.
            Console.WriteLine("排好序的姓和名是:");
            foreach (Student student in sortedStudents)
                Console.WriteLine(student.Last + " " + student.First);

            // 创建分组并排序.             
            var sortedGroups =
                from student in students
                orderby student.Last, student.First
                group student by student.Last[0] into newGroup//按照Lastname的第一个字母进行分组
                orderby newGroup.Key
                select newGroup;

            // 执行查询.
            Console.WriteLine(Environment.NewLine + "分组排序结果是：");
            foreach (var studentGroup in sortedGroups)
            {
                Console.WriteLine("分组的首字母是："+studentGroup.Key);
                foreach (var student in studentGroup)
                {
                    Console.WriteLine("   {0}, {1}", student.Last, student.First);
                }
            }
            
            Console.WriteLine("Press any key to exit.");
            Console.ReadKey();
        }

    }

结果：

排好序的姓和名是:
Garcia Cesar
Mortensen Sven
O'Donnell Claire
Omelchenko Svetlana

分组排序结果是：
分组的首字母是：G
   Garcia, Cesar
分组的首字母是：M
   Mortensen, Sven
分组的首字母是：O
   O'Donnell, Claire
   Omelchenko, Svetlana