Roman Numerals

Question

I am new at VB 2010 and am trying to covert 1-10 into roman numerals so that when you input a 1-10 the roman numeral I-X comes up, this is what I've got so far,and it won't display

Public

 

 

Class Form1

 

 

Private Sub Btnconvert_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnconvert.Click

 

 

'declare the intergers

 

 

Dim intDecimal As Integer

 

 

Dim intDecimal {}Roman_Numeral

　

 

 

'displays the roman numerals

 

 

If intDecimal = 1 Then

Lblroman.Text =

 

"I"

 

 

ElseIf intDecimal = 2 Then

Lblroman.Text =

 

"II"

 

 

ElseIf intDecimal = 3 Then

Lblroman.Text =

 

"III"

 

 

ElseIf intDecimal = 4 Then

Lblroman.Text =

 

"IV"

 

 

ElseIf intDecimal = 5 Then

Lblroman.Text =

 

"V"

 

 

ElseIf intDecimal = 6 Then

Lblroman.Text =

 

"VI"

 

 

ElseIf intDecimal = 7 Then

Lblroman.Text =

 

"VII"

 

 

ElseIf intDecimal = 8 Then

Lblroman.Text =

 

"VIII"

 

 

ElseIf intDecimal = 9 Then

Lblroman.Text =

 

"IX"

 

 

ElseIf intDecimal = 10 Then

Lblroman.Text =

 

"X"

 

 

End If

Lblroman.Text ={

 

""} FormatNumber

 

 

End

　

　

 

 

End Sub

 

 

Private Sub Btnexit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnexit.Click

 

 

Me.Close()

Please Help!! I know it must be something small that I missed?!

Thanx

Answer 1

You haven't set intDecimal to a value.  For instance, if the decimal value is being entered into TextBox1 then you would use

Dim intDecimal as Integer
intDecimal = Val(TextBox1.Text)

(but note that code will fail if the user has left the text box blank).

You could also look at the use of an array to hold the numeral strings, so you could simply use intDecimal as an index into an array.

lblRoman.Text=Numerals(intDecimal)

 

Answer 2

Have a look at this:

 

Dim iNumber as integer = 1

Dim ary As String() = {"I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX", "X"}

Lblroman.Text = ary(iNumber - 1) 'ary is zero based

"CherryHillRich" wrote in message news:9635bb56-a9ff-4301-84a8-b1a3b2eca245...

I am new at VB 2010 and am trying to covert 1-10 into roman numerals so that when you input a 1-10 the roman numeral I-X comes up, this is what I've got so far,and it won't display

Public

 

 

Class Form1

 

 

Private Sub Btnconvert_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnconvert.Click

 

 

'declare the intergers

 

 

Dim intDecimal As Integer

 

 

Dim intDecimal {}Roman_Numeral

　

 

 

'displays the roman numerals

 

 

If intDecimal = 1 Then

Lblroman.Text =

 

"I"

 

 

ElseIf intDecimal = 2 Then

Lblroman.Text =

 

"II"

 

 

ElseIf intDecimal = 3 Then

Lblroman.Text =

 

"III"

 

 

ElseIf intDecimal = 4 Then

Lblroman.Text =

 

"IV"

 

 

ElseIf intDecimal = 5 Then

Lblroman.Text =

 

"V"

 

 

ElseIf intDecimal = 6 Then

Lblroman.Text =

 

"VI"

 

 

ElseIf intDecimal = 7 Then

Lblroman.Text =

 

"VII"

 

 

ElseIf intDecimal = 8 Then

Lblroman.Text =

 

"VIII"

 

 

ElseIf intDecimal = 9 Then

Lblroman.Text =

 

"IX"

 

 

ElseIf intDecimal = 10 Then

Lblroman.Text =

 

"X"

 

 

End If

Lblroman.Text ={

 

""} FormatNumber

 

 

End

　

　

 

 

End Sub

 

 

Private Sub Btnexit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnexit.Click

 

 

Me.Close()

Please Help!! I know it must be something small that I missed?!

Thanx

---

Harry

Answer 3

 

Roman only used the number 1 to 3,899,999 in there numerical system.

Here is a small class that can translate any integer ( 1 to 3,899,999 ) to roman numeral

It is not a solution to your problem, but you might be interested to see

 

Public Class Form1

  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim Val As Integer
    If Integer.TryParse(TextBox1.Text, Val) And Val > 0 And Val < 3899999 Then
      TextBox2.Text = Roman.Int2Roman(Val)
    Else
      TextBox2.Text = "Invalid value"
    End If
  End Sub
End Class



Class Roman
  Private Shared RomanToken() As String = {"(M)", "(C)(M)", "(D)", "(C)(D)", "(C)", _
                   "(X)(C)", "(L)", "(X)(L)", "(X)", "M(X)", _
                   "(V)", "M(V)", "M", "CM", "D", "CD", "C", _
                   "XC", "L", "XL", "X", "IX", "V", "IV", "I"}
  Private Shared TokenValue() As Integer = {1000000, 900000, 500000, 400000, 100000, 90000, _
                   50000, 40000, 10000, 9000, 5000, 4000, 1000, 900, _
                   500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1}

  Public Shared Function Int2Roman(ByVal IntValue As Integer) As String
    If IntValue > 3899999 Or IntValue < 1 Then
      Throw New Exception("Overflow: Roman only used the numbers 1 to 3,899,999")
    Else
      Dim RomanNumeral As String = ""
      For index As Integer = 0 To RomanToken.Count - 1
        Dim Tp As Integer = IntValue \ TokenValue(index)
        IntValue = IntValue - Tp * TokenValue(index)
        While Tp > 0
          RomanNumeral &= RomanToken(index)
          Tp -= 1
        End While
      Next
      Return RomanNumeral
    End If
  End Function
End Class