Play with Last() and LastOrDefault() in LINQ-to-Entities

Introduction

Today, in this article let's play around with one of the interesting and most useful concept in LINQ.

Question: What are these?

Please refer to the below table:

Step 1: Create a new WebForm project

Step 2: The complete code of WebForm1.aspx looks like this

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="LAST_LASTorDefaultLINQApp.WebForm1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

.grid

{

margin-top: 50px;

}

</style>

</head>

<body>

<div>

<table>

<tr>

<asp:Label ID="Label1" runat="server" Text="Play with Last/LastOrDefault using LINQ"

Font-Bold="true" Font-Size="Large" Font-Names="Verdana" ForeColor="Maroon"></asp:Label>

</td>

</tr>

<tr>

<asp:Button ID="Button1" runat="server" Text="Last()" Font-Names="Verdana" Width="213px"

BackColor="Orange" Font-Bold="True" OnClick="Button1_Click" />

</td>

</tr>

<tr>

<asp:Button ID="Button2" runat="server" Text="LastOrDefault()" Font-Names="Verdana"

Width="213px" BackColor="Orange" Font-Bold="True" OnClick="Button2_Click" />

</td>

</tr>

<tr>

<asp:GridView ID="GridView1" runat="server" CssClass="grid" BackColor="LightGoldenrodYellow"

BorderColor="Tan" BorderWidth="1px" CellPadding="2" ForeColor="Black" GridLines="None">

</asp:GridView>

</td>

</tr>

</table>

</div>

</center>

</form>

</body>

</html>

Step 3: The complete code of WebForm1.aspx.cs looks like this

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

namespace LAST_LASTorDefaultLINQApp

{

public partial class WebForm1 : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

}

protected void Button1_Click(object sender, EventArgs e)

{

var query = objEntities.Employee.ToList<Employee>().Last();

var querylist = new List<Employee>

{

query

};

GridView1.DataSource = querylist;

GridView1.DataBind();

}

protected void Button2_Click(object sender, EventArgs e)

{

var query = objEntities.Employee.ToList<Employee>().LastOrDefault();

var querylist = new List<Employee>

{

query

};

GridView1.DataSource = querylist;

GridView1.DataBind();
}

#region Instance Members

CompanyEntities objEntities = new CompanyEntities();

#endregion

}

}

Step 4: The output of the application looks like this

Step 5: The Last () operation output of the application looks like this