|A converter like this is required for any Payroll or Accounts Payable check writing. Sometimes a modified version might be needed as a second description of important numbers in a transaction or such. If you are going to print checks, remember that a large check amount like 1 million will take the entire length of the check, and you might want to consider having a 2 rows available for the description if large checks are the norm and the check allows it.|
I've worked with a number of these converters and have had trouble understanding them enough to make it easy to modify or fix any found bug. This one is simple enough that I feel most people will be able to convert it easily to C#, or any language, and be able to modify the formatting to suite the client's check writing. I did not do this as a web service since it didn't make sense within one application and one server speedwise, and I wouldn't want to rely on a separate server on payroll day.
The dollar class has one public method, convert, that relies on a private method ConvertHundreds which relies on private method ConvertTens. The input string is separated into dollars and cents. The cents are handled entirely within convert method. The dollars are separated after padding to 9 width with 0s to millions, thousands, and hundreds sections that all have 3 digits so that convertHundreds and convertTens will apply symmetrically to them.
Each method is simple enough that it is trivial to add billions, or remove hyphen in forty-five, or put and between each section. It would also be easy to remove reference to dollars and just refer to numbers also. A regular expression validator has been used to make sure the input string is valid enough for this conversion, though the conversion does complete the validation. The only framework elements required were array, replace, split, floor, substring, length, indexof, padleft, and padright. Therefore the only import is system.math for the floor method. Look at the code now and later I will discuss the 2 private methods further.
Public Class Dollar
Dim oneWords As String = ",One,Two,Three,Four,Five,Six,Seven,Eight,Nine,Ten,Eleven,Twelve,Thirteen,Fourteen,Fifteen,Sixteen,Seventeen,Eighteen,Nineteen"
Dim ones() As String = oneWords.Split(",")
Dim tenWords As String = ",Ten,Twenty,Thirty,Forty,Fifty,Sixty,Seventy,Eighty,Ninety"
Dim tens() As String = tenWords.Split(",")
Public Function Convert(ByVal input As String) As String
input = input.Replace("$", "").Replace(",", "")
If input.Length > 12 Then Return "Error in input value"
Dim output, dollars, mills, thous, hunds, cents As String
Dim mill, thou, hund, cent As Integer
If input.IndexOf(".") > 0 Then
dollars = input.Substring(0, input.IndexOf(".")).PadLeft(9, "0")
cents = input.Substring(input.IndexOf(".") + 1).PadRight(2, "0")
If cents = "00" Then cents = "0"
dollars = input.PadLeft(9, "0") : cents = "0"
mill = CType(dollars.Substring(0, 3), Integer) : mills = convertHundreds(mill)
thou = CType(dollars.Substring(3, 3), Integer) : thous = convertHundreds(thou)
hund = CType(dollars.Substring(6, 3), Integer) : hunds = convertHundreds(hund)
cent = CType(cents, Integer) : cents = convertHundreds(cent)
output = IIf(mills.Trim = "", "", mills + " Million ")
output += IIf(thous.Trim = "", "", thous + " Thousand ")
output += IIf(hunds.Trim = "", "", hunds)
output = IIf(output.Length = 0, "Zero Dollars and ", output + " Dollars and ")
output = IIf(output = "One Dollars and ", "One Dollar and ", output)
output += IIf(cents = "", "Zero", cents) + " Cents"
Private Function convertHundreds(ByVal input As Integer) As String
Dim output As String
If input <= 99 Then
output = (convertTens(input))
output = ones(Floor(input / 100))
output += " Hundred "
If input - Floor(input / 100) * 100 = 0 Then
output += ""
output += "" + convertTens(input - Floor(input / 100) * 100)
Private Function convertTens(ByVal input As Integer) As String
Dim output As String
If input < 20 Then
output = ones(input)
input = 0
output = tens(CType(Floor(input / 10), Integer))
input -= Floor(input / 10) * 10
output = output + IIf(ones(input).Trim = "", "", "-" + ones(input))