?
Solved

Convert large Hex to Decimal in VB.NET or Excel

Posted on 2007-11-27
9
Medium Priority
?
10,851 Views
Last Modified: 2008-03-21
I found some java code to convert Hex to Decimal -- but I'd like to do the equivilent in VB.NET -- can you do it?

        BigInteger b = new BigInteger(hexStr, 16);
        String s = b.toString();

I also found Microsoft's answer to do it in VBA, Excel, but since the number is too big it gets trucated - don't know if there's another option here to make this work for me: http://www.vbaexpress.com/kb/getarticle.php?kb_id=307

Hex Str: 76c55e6970d6843011fa94e4433304ea
Decimal Str: 157873700884132896764748183476385285354
0
Comment
Question by:starship_wars
  • 4
  • 2
  • 2
  • +1
9 Comments
 
LVL 93

Expert Comment

by:Patrick Matthews
ID: 20363365
Hello starship_wars,

Please explain what you mean by "truncated".  Excel and VBA are limited to a maximum of
15 significant digits, and cannot maintain any greater precision than that with numeric data.

Regards,

Patrick
0
 

Expert Comment

by:kieranjcollins
ID: 20364996
I doubt Excel formula will ever do it as the formula "=HEX2DEC(A1)" is limited to a 10 character Hex string.
0
 

Expert Comment

by:kieranjcollins
ID: 20365059
Try putting this into an Excel  module and trying the formula:
=HEX2DEC("76c55e6970d6843011fa94e4433304ea") in a worksheet in same workbook.



Option Explicit 
 
Public Function HexToDec(Hex As String) As Double 
     
    Dim i               As Long 
    Dim j               As Variant 
    Dim k               As Long 
    Dim n               As Long 
    Dim HexArray()      As Double 
     
    n = Len(Hex) 
    k = -1 
    ReDim HexArray(1 To n) 
    For i = n To 1 Step -1 
        j = Mid(Hex, i, 1) 
        k = k + 1 
        Select Case j 
        Case 0 To 9 
            HexArray(i) = j * 16 ^ (k) 
        Case Is = "A" 
            HexArray(i) = 10 * 16 ^ (k) 
        Case Is = "B" 
            HexArray(i) = 11 * 16 ^ (k) 
        Case Is = "C" 
            HexArray(i) = 12 * 16 ^ (k) 
        Case Is = "D" 
            HexArray(i) = 13 * 16 ^ (k) 
        Case Is = "E" 
            HexArray(i) = 14 * 16 ^ (k) 
        Case Is = "F" 
            HexArray(i) = 15 * 16 ^ (k) 
        End Select 
    Next i 
    HexToDec = Application.WorksheetFunction.Sum(HexArray) 
     
End Function 

Open in new window

0
Granular recovery for Microsoft Exchange

With Veeam Explorer for Microsoft Exchange you can choose the Exchange Servers and restore points you’re interested in, and Veeam Explorer will present the contents of those mailbox stores for browsing, searching and exporting.

 

Author Comment

by:starship_wars
ID: 20366538
Yes, I have tried Microsoft's code.  But the problem is that I want the value "157873700884132896764748183476385285354" but instead Excel only shows me: 1.57873700884133E+38

If Excel is limited to 15 digits, does anyone know how I can get the result using VB.NET?
0
 
LVL 81

Accepted Solution

by:
zorvek (Kevin Jones) earned 375 total points
ID: 20367738
I don't get the exact result you listed above but it seems to work correctly:

Public Function GetLargeIntegerFromHex( _
      ByVal HexText As String _
   ) As String
   
   Dim Base2 As String
   Dim Result As String
   Dim Index As Long
   Dim Bit As Long
   Dim Char As Byte
   
   Base2 = "1"
   Result = "0"
   
   HexText = UCase(HexText)
   
   For Index = Len(HexText) To 1 Step -1
      Char = CLng("&H" & Mid(HexText, Index, 1))
      For Bit = 1 To 4
         If IsBitSet(Char, Bit) Then Result = AddString(Result, Base2)
         Base2 = AddString(Base2, Base2)
      Next Bit
   Next Index
   
   GetLargeIntegerFromHex = Result

End Function

Public Function AddString( _
      ByVal Value1 As String, _
      ByVal Value2 As String _
   ) As String

   Dim ResultIndex As Long
   Dim OperandIndex As Long
   Dim Result As String
   Dim Operand As String
   Dim Sum As Long
   Dim Carry As Long
   
   If Len(Value1) > Len(Value2) Then
      Result = Value1
      Operand = Value2
   Else
      Result = Value2
      Operand = Value1
   End If
   
   ResultIndex = Len(Result)
   OperandIndex = Len(Operand)
   Do While OperandIndex > 0
      Sum = CLng(Mid(Result, ResultIndex, 1)) + CLng(Mid(Operand, OperandIndex, 1)) + Carry
      If Sum > 9 Then
         Carry = 1
         Mid(Result, ResultIndex, 1) = Sum - 10
      Else
         Carry = 0
         Mid(Result, ResultIndex, 1) = Sum
      End If
      ResultIndex = ResultIndex - 1
      OperandIndex = OperandIndex - 1
   Loop
   If Carry = 1 Then Result = "1" & Result
   
   AddString = Result

End Function

Public Function IsBitSet( _
      ByVal Value As Variant, _
      ByVal Position As Long _
   ) As Boolean
   
   Select Case VarType(Value)
      Case vbLong, vbInteger, vbByte
         IsBitSet = (CLng(Value) And (2 ^ (Position - 1))) > 0
   End Select

End Function

Kevin
0
 

Author Comment

by:starship_wars
ID: 20405614
Sorry for the delayed response.

Kevin, thank you for the good code example.  Too bad the result is just off a few digits, strange.
0
 
LVL 81

Expert Comment

by:zorvek (Kevin Jones)
ID: 20406567
Are you sure your example is correct? I did some pretty extensive testing with my function.

Kevin
0
 

Author Comment

by:starship_wars
ID: 20413583
OMG - I am SO SORRY!!

You are right, I tried a different value and they came out the same.
The one above were the values someone else gave me, so they made an ass-u-me.

Zorvek - Kevin - you are a genius!  Thank you again!
0
 

Author Comment

by:starship_wars
ID: 20495649
I was revisting this code and couldn't get the values to compute again.  I finally figured out a fix by modifying the AddString function:
        If Len(Value1) < Len(Value2) Then
            'Make values the same length by left padding with zeros
            Value1 = Value1.PadLeft(Len(Value2), "0")
        End If
        'If Len(Value1) > Len(Value2) Then
        Result = Value1
        Operand = Value2
        'Else
        '    Result = Value2
        '    Operand = Value1
        'End If
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

If you need to forecast numbers -- typically for finance -- the Windows and Mac versions of Excel 2016 have a basket of tools to get the job done.
Simulator games are perfect for generating sample realistic data streams, especially for learning data analysis. It is even useful for demoing offerings such as Azure stream analytics, PowerBI etc.
This Micro Tutorial demonstrates using Microsoft Excel pivot tables, how to reverse engineer competitors' marketing strategies through backlinks.
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…

850 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question