[RESOLVED] Counting using the alphabet

Hello all,
How do I properly increment (counting) a number using the alphabet? For example,
a + 1 = b
b + 1 = c
......
z + 1 = aa
aa + 1 = ab
.......
Any help is greatly appreciated.

i would use the character values..

chr(97) = a
chr(98) = b

vb Code:

if value > 122 then ' value for z
chr(97) & chr(value - 25)

i think.

edit. this is confusing me. sorry if i made it worse.

I don't know if this will help:
http://www.freevbcode.com/ShowCode.asp?ID=5440

vb.net Code:

Public Sub Numbers()
 
      Dim s As String               ' String value
      Dim v As Integer             ' Character increment
      Dim x As Integer = -1       ' Used for multiple characters
      Dim p As Integer = 97       ' Start of characters.. (97 = a)
 
      For i As Integer = 0 To 200
 
         v = i + p
 
         If (v = 123) Then
            x += 1
            p -= 27
         Else
 
            If x > -1 Then
 
               s = Chr(97 + x) & Chr(v)
 
            Else
 
               s = Chr(v)
 
            End If
 
            Console.WriteLine(s)
 
         End If
 
      Next
 
   End Sub

edit.
works up to zz properly... zz = 728

Quote:

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Originally Posted by nmadd

I don't know if this will help:
http://www.freevbcode.com/ShowCode.asp?ID=5440

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Yeah, that's it... It gave me an idea about the logic behind... Just have to rewrite it using proper VB.Net code :)
Thank you.

You certainly helped me many times, so I'm glad I could finally help you. :bigyello:

I believe you can use the "Asc" method to get the caracter's ASCI code and than add one to it and show the total number by Chr method. Here an example:

vb Code:

Dim myAsci As Integer
myAsci = Asc("a") + 1
Debug.WriteLine(Chr(myAsci))

for the "aa + 1 = ab" you use the same logic. For example the "a" letter asci is 97 and "z"'s is 121 and any thing between are other letters. You can have a flag that if the characters asci + 1 is less than 122 than return Chr(asci).

Here is the method

vb Code:

Private Function SomeThing(ByVal myString As String, ByVal num As Integer) As String
        Dim lastChar As Char = myString.Substring(myString.Length - 1)
        Dim asci As Integer = Asc(lastChar) + num
        If asci > 122 Then
            myString = myString.Substring(0, myString.Length - 1) & "aa"
        Else
            myString = myString.Substring(0, myString.Length - 1) & Chr(asci)
        End If
        Return myString
    End Function

Thank you all who have spent your precious time solving my question... You guys are really helpful :thumb:

To NPassero: while I have no doubt that your code would work correctly up to "zz", however I need a more robust solution - a function that takes a string a spits out the next incremented string regardless of the input length. Your solution seems to work with pre-known, fixed string length only.

To VBDT: Your function does something different than what I expect.... For example, If I plug in "zz", I expect to see the output as "aaa", not "zaa" :)

Anyway, this is the solution, in case someone else is also looking to do the same thing as I'm...

Code:

---

Private Function IncrementString(ByVal input As String) As String
        Dim output As String = String.Empty
        Dim length As Integer = input.Length
        Dim curChar As Char = Nothing
        Dim i As Integer = 0
        If String.IsNullOrEmpty(input) Then
            output = "a"
        Else
            For i = length - 1 To 0 Step -1
                curChar = input(i)
                If curChar = "z"c Then
                    input = input.Substring(0, i) & "a" & input.Substring(i + 1)
                    If i = 0 Then
                        input = "a" & input
                    End If
                Else
                    input = input.Substring(0, i) & Chr(Asc(curChar) + 1) & input.Substring(i + 1)
                    Exit For
                End If
            Next
            output = input
        End If
        Return output
    End Function

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Gotcha, didn't know the functionality that you were using it for. good work.