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.