Sorting Date in a Generic List using LINQ

Let us say you have a Generic List with you which contains a Date Field. You now want to sort Date in the Generic List and want to do it in the simplest possible way, then here's how to do so. I have added a DropDownList for demonstration purpose to display the results:

C#

using System;


using System.Collections.Generic;


using System.Linq;


using System.Web;


using System.Web.UI;


using System.Web.UI.WebControls;


 


 


public partial class LINQ : System.Web.UI.Page


{


    protected void Page_Load(object sender, EventArgs e)


    {


 


        List<Employee> empList = new List<Employee>();


        empList.Add(new Employee() { ID = 1, FName = "John",  DOB = DateTime.Parse("12/11/1971")});


        empList.Add(new Employee() { ID = 2, FName = "Mary",  DOB = DateTime.Parse("01/17/1961")});


        empList.Add(new Employee() { ID = 3, FName = "Amber", DOB = DateTime.Parse("12/23/1971")});


        empList.Add(new Employee() { ID = 4, FName = "Kathy", DOB = DateTime.Parse("11/15/1976")});


        empList.Add(new Employee() { ID = 5, FName = "Lena",  DOB = DateTime.Parse("05/11/1978")});


 


        empList.Sort((x, y) => (x.DOB.CompareTo(y.DOB)));


 


        empList.ForEach(delegate(Employee em)


        {


            DropDownList1.Items.Add(em.DOB.ToString());


        });


 


    }


 


    class Employee


    {


        public int ID { get; set; }


        public string FName { get; set; }


        public DateTime DOB { get; set; }


    }


 


}





VB.NET

Imports System


Imports System.Collections.Generic


Imports System.Linq


Imports System.Web


Imports System.Web.UI


Imports System.Web.UI.WebControls


 


 


Partial Public Class LINQ


    Inherits System.Web.UI.Page


    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)


 


        Dim empList As New List(Of Employee)()


        empList.Add(New Employee() With {.ID = 1, .FName = "John", .DOB = DateTime.Parse("12/11/1971")})


        empList.Add(New Employee() With {.ID = 2, .FName = "Mary", .DOB = DateTime.Parse("01/17/1961")})


        empList.Add(New Employee() With {.ID = 3, .FName = "Amber", .DOB = DateTime.Parse("12/23/1971")})


        empList.Add(New Employee() With {.ID = 4, .FName = "Kathy", .DOB = DateTime.Parse("11/15/1976")})


        empList.Add(New Employee() With {.ID = 5, .FName = "Lena", .DOB = DateTime.Parse("05/11/1978")})


 


        empList.Sort(Function(x, y) (x.DOB.CompareTo(y.DOB)))


 


        empList.ForEach(AddressOf AnonymousMethod1)


 


    End Sub


    Private Sub AnonymousMethod1(ByVal em As Employee)


        DropDownList1.Items.Add(em.DOB.ToString())


    End Sub


 


    Private Class Employee


        Private privateID As Integer


        Public Property ID() As Integer


            Get


                Return privateID


            End Get


            Set(ByVal value As Integer)


                privateID = value


            End Set


        End Property


        Private privateFName As String


        Public Property FName() As String


            Get


                Return privateFName


            End Get


            Set(ByVal value As String)


                privateFName = value


            End Set


        End Property


        Private privateDOB As DateTime


        Public Property DOB() As DateTime


            Get


                Return privateDOB


            End Get


            Set(ByVal value As DateTime)


                privateDOB = value


            End Set


        End Property


    End Class


 


End Class




Here we make use of the List.Sort to do an in place sorting.

After sorting the dates, the result will be as displayed below:



Will you give this article a +1 ? Thanks in advance


About The Author

Suprotim Agarwal
Suprotim Agarwal, ASP.NET Architecture MVP (Microsoft Most Valuable Professional) works as an Architect Consultant and provides consultancy on how to design and develop Web applications.

Suprotim is also the founder and primary contributor to DevCurry, DotNetCurry and SQLServerCurry. He is the Editor of a Developer Magazine called DNC Magazine. He has also written two EBooks 51 Recipes using jQuery with ASP.NET Controls. and The Absolutely Awesome jQuery CookBook

Follow him on twitter @suprotimagarwal

1 comment:

Luke said...

Great post, was exactly what i was looking for.