Bubble Sort Question for multideminsional array

Hi guys--

I'm new to VB .net so please bare with me. I am trying to read in a range of values from an excel worksheet and sort them, eventually writting to a seperate file.

For now, i have built a multideminsional array of strings w/ the values from excel.

I am having some difficulties in developing the algorithm to sort them only on the first column. would appreciate it if someone could please provide some pointers or post some code.

Thxs

code

OK, so i had *alot* more time to work on this today than what i had thought. here is my initial pass, any comments / suggestions are welcome as i'm pretty new to VB.

Module Sort
   Public Const numDimensions As Integer = 5
   Public qstArray(5, numDimensions) As String

   Sub BubbleSort(ByRef strArray(,) As String, ByVal numDimensions As Integer)
       'This function will sort our array.  It takes the 2 dim. array that was extracted 
       'from the excel file and the number of columns.
       'Yes, this is a very slow algorithm, but this is only a prototype.  This function 
       'can be optimized in the next release

       Dim intCounter, EventLoop, i As Integer
       Dim Temp(1, numDimensions) As String

       For EventLoop = 1 To UBound(strArray)
           For intCounter = 1 To UBound(strArray) - 1
               If strArray(intCounter, 1) > strArray(intCounter + 1, 1) Then
                   'swap our values.  seperate loops to handle the 2 dimensional array
                   For i = 1 To numDimensions
                       Temp(1, i) = strArray(intCounter, i)
                   Next i
                   For i = 1 To numDimensions
                       strArray(intCounter, i) = strArray(intCounter + 1, i)
                   Next i
                   For i = 1 To numDimensions
                       strArray(intCounter + 1, i) = Temp(1, i)
                   Next i
               End If
           Next intCounter
       Next EventLoop

   End Sub

End Module

I have a few observations:

1. 
   
2. You have a constant named "numDimensions" and you also have a parameter with the same name. This could get confusing.
    
   
3. Arrays are usually zero based but your loops start at one. You could get the lower index from the array itself instead of hard-coding it.
    
   
4. You are using UBound which is part of the Microsoft.VisualBasic namespace. I'm unsure of whether there is a .NET equivalent as I am relatively new to .NET but generally speaking you should avoid this namespace unless you have no choice.
   

1. Arrays are usually zero based but your loops start at one. You could get the lower index from the array itself instead of hard-coding it.
   

On further investigation, according to the MSDN documentation "The lower bound for array subscripts is always 0".

Here's one that I've just written. It can work with 1 or 2 dimension arrays and doesn't require additional information about the size of the dimensions as it works them out. I have also optimised the routine.

   Sub BubbleSort(ByRef stringArray As Array)
     'This function will sort an array (1 or 2 dimension only) based on the first dimension.

     Dim nDimensions As Short
     Dim nPasses As Short
     Dim nIndex As Short
     Dim bSorted As Boolean
     Dim nCount As Short
     Dim tempString As String

     nPasses = 0
     nDimensions = stringArray.Rank

     Do
        nIndex = 0
        bSorted = True
        While nIndex < stringArray.GetUpperBound(0) - nPasses
           If nDimensions > 1 Then
              If stringArray(nIndex, 0) > stringArray(nIndex + 1, 0) Then
                 bSorted = False
                 For nCount = 0 To stringArray.GetUpperBound(1)
                    tempString = stringArray(nIndex, nCount)
                    stringArray(nIndex, nCount) = stringArray(nIndex + 1, nCount)
                    stringArray(nIndex + 1, nCount) = tempString
                 Next
              End If
           Else
              If stringArray(nIndex) > stringArray(nIndex + 1) Then
                 bSorted = False
                 tempString = stringArray(nIndex)
                 stringArray(nIndex) = stringArray(nIndex + 1)
                 stringArray(nIndex + 1) = tempString
              End If
           End If
           nIndex += 1
        End While
        nPasses += 1
     Loop Until bSorted Or (nPasses >= stringArray.GetUpperBound(0))

  End Sub

  Sub TestBubbleSort()

     Dim myArray(4, 4) As String
     Dim X As Short, Y As Short
     For X = 0 To 4
        For Y = 0 To 4
           myArray(X, Y) = Microsoft.VisualBasic.ChrW(69 - X).ToString & (Y + 1).ToString
        Next
     Next

     BubbleSort(myArray)

     Dim myArray2(9) As String
     For X = 0 To 9
        myArray2(X) = Microsoft.VisualBasic.ChrW(74 - X).ToString
     Next

     BubbleSort(myArray2)

  End Sub

Hey Techno-

Thanks for the pointers!

hey folks,

im in the middle of writing a prgm to update inventory transactions, im stumped as to what comes next.... i built and initiated the table, i have built the save field in Working storage, and the sort rtn, and initiaon rtn's... what do i include in the sort rtne? does anybody have knowledge of how this needs to be s/u?

assignii.txt