022 LINQ OrderBy and OrderByDescending

A sorting operator arranges the elements of the collection in ascending or descending order.

Here is the example of sorting by name.The example shows that how sorting can be done ascending or descending order with LINQ query.

Example

-------------------------------------------------------

using System;

using System.Collections.Generic;

using System.Data.SqlClient;

using System.Data.Sql;

using System.Data;

using System.Linq;

using System.Collections;

using System.Xml;

using System.Xml.Linq;

using System.IO;

namespace ConsoleApplication1

{

              class Program

              {

                  static void Main(string[] args)

                  {

                     var students = new student[]

                                {

                                    new student{name = "John1",roll=123,age=12},

                                    new student{name = "John2",roll=124,age=13},

                                    new student{name = "John3",roll=125,age=14},

                                    new student{name = "John4",roll=126,age=15},

                                    new student{name = "John5",roll=127,age=16},

                                    new student{name = "John6",roll=128,age=17},

                                    new student{name = "John7",roll=129,age=18}

                              };

/************Example of Order ***************************/

Console.WriteLine("*************Example of Order by Name***********/");

                var query1 = from s in students

                                       orderby s.name

                                       select s;

                           foreach (var obj in query1)

                          {

                               Console.WriteLine("Name :{0} ,Age :{1},Roll :{2}", obj.name, obj.age, obj.roll);

                          }

Console.WriteLine("*************Example of Order by Name Decending***********/");

             var query2 = from s in students

                                    orderby s.name descending

                                    select s;

                          foreach (var obj in query2)

                           {

                                       Console.WriteLine("Name :{0} ,Age :{1},Roll :{2}", obj.name, obj.age, obj.roll);

                          }

                       Console.ReadKey();

                       }

           }

}

public class student

{

            public string name { get; set; }

            public int roll { get; set; }

            public int age { get; set; }

}

Output :

*************Example of Order by Name***********/
Name :John1 ,Age :12,Roll :123
Name :John2 ,Age :13,Roll :124
Name :John3 ,Age :14,Roll :125
Name :John4 ,Age :15,Roll :126
Name :John5 ,Age :16,Roll :127
Name :John6 ,Age :17,Roll :128
Name :John7 ,Age :18,Roll :129



*************Example of Order by Name Decending***********/
Name :John7 ,Age :18,Roll :129
Name :John6 ,Age :17,Roll :128
Name :John5 ,Age :16,Roll :127
Name :John4 ,Age :15,Roll :126
Name :John3 ,Age :14,Roll :125
Name :John2 ,Age :13,Roll :124
Name :John1 ,Age :12,Roll :123

------------------------------------------------------------------------------------





Below is the example of sorting with Lambda expression.The query is sorted by name with Lambda expression both ascending or descending order.

Example

----------------------------------------------------------

using System;

using System.Collections.Generic;

using System.Data.SqlClient;

using System.Data.Sql;

using System.Data;

using System.Linq;

using System.Collections;

using System.Xml;

using System.Xml.Linq;

using System.IO;

namespace ConsoleApplication1

{

          class Program

          {

             static void Main(string[] args)

             {

                  var students = new student[]

                  {

                    new student{name = "John1",roll=123,age=12},

                    new student{name = "John2",roll=124,age=13},

                    new student{name = "John3",roll=125,age=14},

                    new student{name = "John4",roll=126,age=15},

                    new student{name = "John5",roll=127,age=16},

                    new student{name = "John6",roll=128,age=17},

                   new student{name = "John7",roll=129,age=18}

               };

Console.WriteLine("*************Example of Order by Name***********/");

              var query = students.OrderBy(a => a.name);

              foreach (var obj in query)

              {

             Console.WriteLine("Name :{0} ,Age :{1},Roll :{2}", obj.name, obj.age, obj.roll);

             }

Console.WriteLine("*************Example of Order by Name Decending***********/");

            var query2 = students.OrderByDescending(a => a.name);

           foreach (var obj in query2)

           {

                Console.WriteLine("Name :{0} ,Age :{1},Roll :{2}", obj.name, obj.age, obj.roll);

           }

       Console.ReadKey();

      }

   }

}

public class student

{

      public string name { get; set; }

      public int roll { get; set; }

      public int age { get; set; }

}

Output :

-------------------------------------------------------------------------------

*************Example of Order by Name***********/
Name :John1 ,Age :12,Roll :123
Name :John2 ,Age :13,Roll :124
Name :John3 ,Age :14,Roll :125
Name :John4 ,Age :15,Roll :126
Name :John5 ,Age :16,Roll :127
Name :John6 ,Age :17,Roll :128
Name :John7 ,Age :18,Roll :129
*************Example of Order by Name Decending***********/
Name :John7 ,Age :18,Roll :129
Name :John6 ,Age :17,Roll :128
Name :John5 ,Age :16,Roll :127
Name :John4 ,Age :15,Roll :126
Name :John3 ,Age :14,Roll :125
Name :John2 ,Age :13,Roll :124
Name :John1 ,Age :12,Roll :123