How do I convert a number in to its written form?

[Steven Sargent]

How can I convert a number into its written form?
For example, I input 15, and the program will output "fifteen".
I'm doing this in a console application. It would be better if, instead of giving me the full answer, you could set me on the right path.

All I can think of now is a very long switch structure for every character in the number.

[GaryTexmo]

I don't think you need a giant switch statement... You can lay down some rules and check for compliance:

* 0-9 have a specific equivalent word associated with them
* 10 added to any of the first adds postfix of "teen", with the exception of 11 and 12 which are single mapping
* 20, 30, ..., 90 added to any of the first adds a prefix of the word equivalent of those
* 100, 200, ..., 900 added to the above set also adds another prefix

Then I'd start parsing the number by digit and digit sets, trying to fit pieces of them into the above categories and building the word string as I can. You can check the length of the number or subset to see what prefix you should generate, perhaps?

I don't know if this is the correct way or not, I've never done this before and you've asked for a nudge. If I were to approach this problem, I believe this is how I'd start.

I hope that helps!

[Steven Sargent]

Actually, that's exactly what I had considered first... I don't think I explained myself well.

At any rate, I was hoping there was a quicker way that I wasn't seeing.

Thanks.

[john garvey]

Here is a solution I wrote in VB which will convert any money value below 99,999,999.99 into text which will be gramatically correct. You could butcher this to get what you need

' PayNum is a monetry value, in this case £GBPounds, with or without decimal places for pence
' The returned string is gramatically correct, as if you wrote a cheque (check)



Option Explicit
Dim strUnder21(1 To 20) As String
Dim strTens(1 To 9) As String


Public Function NumToConvert(PayNum As String) As String

' Initialise the arrays
strUnder21(1) = "One "
strUnder21(2) = "Two "
strUnder21(3) = "Three "
strUnder21(4) = "Four "
strUnder21(5) = "Five "
strUnder21(6) = "Six "
strUnder21(7) = "Seven "
strUnder21(8) = "Eight "
strUnder21(9) = "Nine "
strUnder21(10) = "Ten "
strUnder21(11) = "Eleven "
strUnder21(12) = "Twelve "
strUnder21(13) = "Thirteen "
strUnder21(14) = "Fourteen "
strUnder21(15) = "Fifteen "
strUnder21(16) = "Sixteen "
strUnder21(17) = "Seventeen"
strUnder21(18) = "Eighteen "
strUnder21(19) = "Nineteen "
strUnder21(20) = "Twenty "

strTens(1) = "Ten "
strTens(2) = "Twenty "
strTens(3) = "Thirty "
strTens(4) = "Fourty "
strTens(5) = "Fifty "
strTens(6) = "Sixty "
strTens(7) = "Seventy "
strTens(8) = "Eighty "
strTens(9) = "Ninety "

NumToConvert = PoundsPence(PayNum)


End Function

Public Function PoundsPence(PayNum As String) As String
Dim Po As String, Pe As String, pence As Integer
Dim start As Integer, Nt As String
On Error GoTo Err_PoundsPence
start = InStr(PayNum, ".")
If start = 0 Then
Po = getPounds(PayNum, Nt)
Else
Po = Left(PayNum, start - 1)
pence = Val(Right(PayNum, Len(PayNum) - (Len(Po) + 1)))
PayNum = Po
Po = getPounds(PayNum, Nt)
If getDigitsToText(pence, Nt) Then
Pe = Nt & " pence"
Pe = Replace(Pe, " ", " ")
End If
End If
PoundsPence = Po & Pe
PoundsPence = UCase(Left(PoundsPence, 1)) & LCase(Right(PoundsPence, Len(PoundsPence) - 1))
Exit_PoundsPence:
Exit Function
Err_PoundsPence:
MsgBox Error$
Resume Exit_PoundsPence
End Function

Private Function getPounds(PayNum As String, Nt As String) As String
Dim Tm As Integer, Tms As String
Dim Ht As Integer, Hts As String
Dim tt As Integer, tts As String
Dim H As Integer, Hs As String
Dim t As Integer, ts As String
On Error GoTo Err_NumToText

Nt = Right("00000000" & PayNum, 8)
Tm = Val(Mid(Nt, Len(Nt) - 8 + 1, 2))
Ht = Val(Mid(Nt, Len(Nt) - 6 + 1, 1))
tt = Mid(Nt, Len(Nt) - 5 + 1, 2)
H = Val(Mid(Nt, Len(Nt) - 3 + 1, 1))
t = Val(Mid(Nt, Len(Nt) - 2 + 1, 2))

' Millions
If getDigitsToText(Tm, Tms) Then
Tms = Tms & "million "
End If
' Hundred Thousands
If getDigitsToText(Ht, Hts) Then
Hts = Hts & "hundred "
End If
' Ten thousands/ thousands
If getDigitsToText(tt, tts) Then
If Ht > 0 Then tts = "and " & tts
End If
If (Ht > 0) Or (tt > 0) Then
tts = tts & "thousand "
End If
' Hundreds
If getDigitsToText(H, Hs) Then
Hs = Hs & "hundred "
End If
' Tens and units
If getDigitsToText(t, ts) Then
If (Tm > 0) Or (Ht > 0) Or (tt > 0) Or (H > 0) Then ts = "and " & ts
End If
getPounds = Tms & Hts & tts & Hs & ts
getPounds = Replace(getPounds, " -", "-")
getPounds = Replace(getPounds, " ", " ")

If Len(getPounds & "") > 0 Then
getPounds = getPounds & "pounds "
End If

Exit_NumToText:
Exit Function
Err_NumToText:
MsgBox Error$
Resume Exit_NumToText
End Function

Private Function getDigitsToText(iNum As Integer, txtAmount As String) As Boolean
Dim iUnit As Integer
iUnit = iNum Mod 10
Select Case iNum
Case 0
txtAmount = ""
Case Is < 21
txtAmount = strUnder21(iNum)
Case Else
txtAmount = strTens((iNum - (iNum Mod 10)) / 10)
If iUnit > 0 Then
txtAmount = txtAmount & "-" & strUnder21(iUnit)
End If
End Select
getDigitsToText = (iNum > 0)
End Function