Introduction
Today, in this article let's
play around with one of the interesting and most useful concept in .NET.
Question: What
is copy constructor?
In simple terms "It enables
to copy the values into new object from existing object".
Step 1: Create
a new WebForm project

Step 2: The
complete code of Arithmetic.cs looks like this:
using
System;
using
System.Collections.Generic;
using
System.Linq;
using
System.Web;
namespace
Copy_ConstructorApp
{
public class Arithmetic
{
public double a;
public double b;
public Arithmetic(Arithmetic
arthmetic)
{
a = arthmetic.a;
b = arthmetic.b;
}
public Arithmetic(double
a, double b)
{
this.a = a; this.b
= b;
}
public double
Add()
{
return a + b;
}
public double
Sub()
{
return a - b;
}
public double
Mul()
{
return a * b;
}
public double
Div()
{
return a / b;
}
}
}
Step 3: The
complete code WebForm1.aspx looks like this: <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="Copy_ConstructorApp.WebForm1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<center>
<div>
<table>
<tr>
<td colspan="2">
<asp:Label ID="Label1" runat="server" Text="Copy Constructor
in .NET" Font-Bold="true"
Font-Size="Large" Font-Names="Verdana" ForeColor="Maroon"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label3" runat="server" Text="Please Enter First
Number" Font-Size="Large"
Font-Names="Verdana" Font-Italic="true"></asp:Label>
</td>
<td>
<asp:TextBox ID="TextBox1" runat="server" Width="120px"></asp:TextBox>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label2" runat="server" Text="Please Enter
Second Number" Font-Size="Large"
Font-Names="Verdana" Font-Italic="true"></asp:Label>
</td>
<td>
<asp:TextBox ID="TextBox2" runat="server" Width="120px"></asp:TextBox>
</td>
</tr>
<tr>
<td colspan="2" align="center">
<asp:Button ID="Button1" 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="Button2" 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="Button3" 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="Button4" 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="Label5" runat="server" Font-Bold="true" Font-Names="Verdana" ForeColor="Maroon"></asp:Label>
</td>
</tr>
</table>
</div>
</center>
</form>
</body>
</html>
Step 4: The
complete code 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
Copy_ConstructorApp
{
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(TextBox1.Text)
|| string.IsNullOrEmpty(TextBox2.Text))
{
Label5.Text =
"Please Enter Some Values"; Label5.ForeColor
= System.Drawing.Color.Red;
}
else
{
Arithmetic
obj_Arithmetic = new Arithmetic(double.Parse(TextBox1.Text),
double.Parse(TextBox2.Text));
Arithmetic
obj_CopyArithmetic = new
Arithmetic(obj_Arithmetic);
Label5.Text =
"Addition Result is: " +
obj_CopyArithmetic.Add();
Label5.ForeColor = System.Drawing.Color.Green;
TextBox1.Text
= string.Empty; TextBox2.Text =
string.Empty;
}
}
protected void
Button2_Click(object sender,
EventArgs e)
{
if (string.IsNullOrEmpty(TextBox1.Text)
|| string.IsNullOrEmpty(TextBox2.Text))
{
Label5.Text =
"Please Enter Some Values"; Label5.ForeColor
= System.Drawing.Color.Red;
}
else
{
Arithmetic
obj_Arithmetic = new Arithmetic(double.Parse(TextBox1.Text),
double.Parse(TextBox2.Text));
Arithmetic
obj_CopyArithmetic = new
Arithmetic(obj_Arithmetic);
Label5.Text =
"Substraction Result is: " +
obj_CopyArithmetic.Sub();
Label5.ForeColor = System.Drawing.Color.Green;
TextBox1.Text
= string.Empty; TextBox2.Text =
string.Empty;
}
}
protected void
Button3_Click(object sender,
EventArgs e)
{
if (string.IsNullOrEmpty(TextBox1.Text)
|| string.IsNullOrEmpty(TextBox2.Text))
{
Label5.Text =
"Please Enter Some Values";
Label5.ForeColor = System.Drawing.Color.Red;
}
else
{
Arithmetic
obj_Arithmetic = new Arithmetic(double.Parse(TextBox1.Text),
double.Parse(TextBox2.Text));
Arithmetic
obj_CopyArithmetic = new
Arithmetic(obj_Arithmetic);
Label5.Text =
"Multiplication Result is: " +
obj_CopyArithmetic.Mul();
Label5.ForeColor = System.Drawing.Color.Green;
TextBox1.Text
= string.Empty; TextBox2.Text =
string.Empty;
}
}
protected void
Button4_Click(object sender,
EventArgs e)
{
if (string.IsNullOrEmpty(TextBox1.Text)
|| string.IsNullOrEmpty(TextBox2.Text))
{
Label5.Text =
"Please Enter Some Values"; Label5.ForeColor
= System.Drawing.Color.Red;
}
else
{
Arithmetic
obj_Arithmetic = new Arithmetic(double.Parse(TextBox1.Text),
double.Parse(TextBox2.Text));
Arithmetic
obj_CopyArithmetic = new
Arithmetic(obj_Arithmetic);
Label5.Text =
"Division Result is: " +
obj_CopyArithmetic.Div();
Label5.ForeColor = System.Drawing.Color.Green;
TextBox1.Text
= string.Empty; TextBox2.Text =
string.Empty;
}
}
}
}
Step 5: The
output of application looks like this:

Step 6: The
addition result output of application looks like this:
