Ejercicio: n factorial

Public Class frmFactorial

    Private Sub btnCalcular_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalcular.Click
        Dim resultado As Integer

        If nudFactorial.Value = 1 Or nudFactorial.Value = 0 Then
            resultado = 1
        Else
            resultado = nudFactorial.Value
            For i As Integer = nudFactorial.Value To 1 Step -1
                If i <> 1 Then
                    resultado *= i - 1
                End If
            Next
        End If

        lblResultado.Text = "El factorial de " & nudFactorial.Value & " es " & resultado.ToString
    End Sub

    Private Sub frmFactorial_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        lblResultado.Text = ""
    End Sub
End Class