Decimal To Roman Numeral in Visual Basic NET

Here is a sample program to ask the user to give a number and then it will convert in Roman Numeral equivalent using Microsoft Visual Basic NET.  The code is very short and easy to understand. Thank you.

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Sample Program Output

Program Listing

Public Class Form1

    Private Function ConvertRoman(ByVal n As Integer) As String

        If n = 0 Then ConvertRoman = "0" : Exit Function

        Const r = "IVXLCDM"

        Dim i As Integer = Math.Abs(n)

        Dim s As String = ""

        For p As Integer = 1 To 5 Step 2

            Dim d As Integer = i Mod 10

            i = i \ 10

            Select Case d '

                Case 0 To 3 : s = s.PadLeft(d + Len(s), Mid(r, p, 1))

                Case 4 : s = Mid(r, p, 2) & s

                Case 5 To 8 : s = Mid(r, p + 1, 1) & s.PadLeft(d - 5 + Len(s), Mid(r, p, 1))

                Case 9 : s = Mid(r, p, 1) & Mid(r, p + 2, 1) & s

            End Select

        Next

        s = s.PadLeft(i + Len(s), "M")

        If n < 0 Then s = "-" & s

        ConvertRoman = s

    End Function

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        Label2.Text = " The equivalent value of " & TextBox1.Text & " is " & ConvertRoman(TextBox1.Text) & "."

    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click

        TextBox1.Text = ""

        Label2.Text = ""

        TextBox1.Focus()

    End Sub

    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click

        End

    End Sub

End Class