Calculate factorial of a number using C# and VB.net

Introduction:

 In this article i have explained how to calculate factorial of a number in asp.net. 

• In the design page(.aspx) place two text boxes and a button as:

<table>

            <tr>

                <td>

                    Enter number</td>

                <td>

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

                </td>

            </tr>

            <tr>

                <td>

                    &nbsp;</td>

                <td>

                    <asp:Button ID="btnFactorial" runat="server" Text="Find  factorial"

                        onclick="btnFactorial_Click" />

                </td>

            </tr>

            <tr>

                <td>

                    Output:</td>

                <td>

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

                </td>

            </tr>

        </table>

• Now in the code behind file(.aspx.cs) write the code as:

C#.Net Code to get/find/calculate factorial of a number using C# and VB.net

    protected void btnFactorial_Click(object sender, EventArgs e)

    {

        int count = 1, factorial = 1, number = 1, factorialNumber;

        factorialNumber = Convert.ToInt32(txtNumber.Text);

        while (count <= factorialNumber)

        {

            factorial = factorial * number;

            count++;

            number++;

        }

        txtFactorial.Text = factorial.ToString();

    }

VB.Net Code to calculate factorial of a number using C# and VB.net

• Now in the code behind file(.aspx.vb) write the code as:

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

        Dim count As Integer = 1, factorial As Integer = 1, number As Integer = 1, factorialNumber As Integer

        factorialNumber = Convert.ToInt32(txtNumber.Text)

        While count <= factorialNumber

            factorial = factorial * number

            count += 1

            number += 1

        End While

        txtFactorial.Text = factorial.ToString()

    End Sub