Blog

Lambda Expressions in C#

By Vijay Prativadi Blogs | Visual C# Oct 12, 2012
Today, in this blog let’s play around with one of the interesting and most useful concept in C#.

Introduction

 

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

 

Question: What are lambda expressions?

 

In simple terms "It is an anonymous function which accepts some input parameters and performs an expected operation with lambda operator."

 

Step 1: Create a new webform project

 

pic1.png
 

Step 2: The complete code of webform1.aspx looks like this

 

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

 

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">

<head id="Head2" runat="server">

    <title></title>

</head>

<body>

    <form id="form1" runat="server">

    <center>

        <div>

            <table>

                <tr>

                    <td colspan="2" align="center">

                        <asp:Label ID="Label3" runat="server" Text="Arithmetic Operations with Lambda Expressions in C#"

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

                    </td>

                </tr>

                <tr>

                    <td>

                        <asp:Label ID="Label4" runat="server" Text="Please Enter FirstNumber" Font-Size="Large"

                            Font-Names="Verdana" Font-Italic="true"></asp:Label>

                    </td>

                    <td>

                        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>

                    </td>

                </tr>

                <tr>

                    <td>

                        <asp:Label ID="Label7" runat="server" Text="Please Enter SecondNumber" Font-Size="Large"

                            Font-Names="Verdana" Font-Italic="true"></asp:Label>

                    </td>

                    <td>

                        <asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>

                    </td>

                </tr>

                <tr>

                    <td colspan="2" align="center">

                        <asp:Button ID="Button5" runat="server" Text="Addition" Font-Names="Verdana" Width="213px"

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

                    </td>

                </tr>

                <tr>

                    <td colspan="2" align="center">

                        <asp:Button ID="Button6" runat="server" Text="Substraction" Font-Names="Verdana"

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

                    </td>

                </tr>

                <tr>

                    <td colspan="2" align="center">

                        <asp:Button ID="Button7" runat="server" Text="Multiplication" Font-Names="Verdana"

                            Width="213px" BackColor="Orange" Font-Bold="True" OnClick="Button3_Click" />

                    </td>

                </tr>

                <tr>

                    <td colspan="2" align="center">

                        <asp:Button ID="Button8" runat="server" Text="Division" Font-Names="Verdana" Width="213px"

                            BackColor="Orange" Font-Bold="True" OnClick="Button4_Click" />

                    </td>

                </tr>

                <tr>

                    <td colspan="2" align="center">

                        <asp:Label ID="Label8" runat="server" Font-Bold="true" Font-Names="Verdana"></asp:Label>

                    </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 LamdaExpressionApp

{

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

    {

        protected void Page_Load(object sender, EventArgs e)

        {

        }

        protected void Button1_Click(object sender, EventArgs e)

        {

            if (string.IsNullOrEmpty(TextBox4.Text) || string.IsNullOrEmpty(TextBox1.Text))

            {

                Label5.Text = "Please Enter Some Values";Label5.ForeColor = System.Drawing.Color.Red;

            }

            else

            {

                ArithmticDelegate objAdd = (x, y) => x + y;

                Label5.Text = "Addition Result is: " + objAdd.Invoke(double.Parse(TextBox4.Text), double.Parse(TextBox1.Text));

                Label5.ForeColor = System.Drawing.Color.Green;TextBox1.Text = string.Empty;

                TextBox4.Text = string.Empty;

            }

        }

        protected void Button2_Click(object sender, EventArgs e)

        {

            if (string.IsNullOrEmpty(TextBox4.Text) || string.IsNullOrEmpty(TextBox1.Text))

            {

                Label5.Text = "Please Enter Some Values";

                Label5.ForeColor = System.Drawing.Color.Red;

            }

            else

            {

                ArithmticDelegate objSub = (x, y) => x - y;

                Label5.Text = "Substraction Result is: " + objSub.Invoke(double.Parse(TextBox4.Text), double.Parse(TextBox1.Text));

                Label5.ForeColor = System.Drawing.Color.Green;TextBox1.Text = string.Empty;TextBox4.Text = string.Empty;

            }

        }

        protected void Button3_Click(object sender, EventArgs e)

        {

            if (string.IsNullOrEmpty(TextBox4.Text) || string.IsNullOrEmpty(TextBox1.Text))

            {

                Label5.Text = "Please Enter Some Values";Label5.ForeColor = System.Drawing.Color.Red;

            }

            else

            {

                ArithmticDelegate objMul = (x, y) => x * y;Label5.Text = "Multiplication Result is: " + objMul.Invoke(double.Parse(TextBox4.Text), double.Parse(TextBox1.Text));

                Label5.ForeColor = System.Drawing.Color.Green;TextBox1.Text = string.Empty;TextBox4.Text = string.Empty;

            }

        }

        protected void Button4_Click(object sender, EventArgs e)

        {

            if (string.IsNullOrEmpty(TextBox4.Text) || string.IsNullOrEmpty(TextBox1.Text))

            {

                Label5.Text = "Please Enter Some Values";

                Label5.ForeColor = System.Drawing.Color.Red;

            }

            else

            {

                ArithmticDelegate objDiv = (x, y) => x / y;

                Label5.Text = "Division Result is: " + objDiv.Invoke(double.Parse(TextBox4.Text), double.Parse(TextBox1.Text));

                Label5.ForeColor = System.Drawing.Color.Green;

                TextBox1.Text = string.Empty;TextBox4.Text = string.Empty;

            }

        }

        #region Public Memberspublic delegate double ArithmticDelegate(double a, double b);

        #endregion

    }

}

 

Step 4: The output of the application looks like this
 

Output2.png
 

Step 5: The addition operation output of the application looks like this

  Output3.png

I hope this article is useful for you.

COMMENT USING