using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public class Student

    {

        public int StudentID {get;set;}

        public string StudentName {get;set;}

        public int Age {get;set;}

        public int StandardID {get;set;}

    }

    public static void Main()

    {

        IList<Student> studentList = new List<Student>() { 

                    new Student() { StudentID = 1, StudentName = "John", Age = 18, StandardID = 1 } ,

                    new Student() { StudentID = 2, StudentName = "Steve",  Age = 21, StandardID = 1 } ,

                    new Student() { StudentID = 3, StudentName = "Bill",  Age = 18, StandardID = 2 } ,

                    new Student() { StudentID = 4, StudentName = "Ram" , Age = 20, StandardID = 2 } ,

                    new Student() { StudentID = 5, StudentName = "Ron" , Age = 21 

                                  } 

        };

        var sortedList = from s in studentList

                              group s by s.StandardID into sg

                              orderby sg.Key 

                                    select new { sg.Key, sg };

​

        foreach (var group in sortedList)

        {

            Console.WriteLine(string.Format("**{0}**", group.Key));         

            group.sg.ToList().ForEach(st => Console.WriteLine(st.StudentName ));

            Console.WriteLine(Environment.NewLine);

        }

​

    }

}