XL: Using a Visual Basic Macro to Sort Arrays in Microsoft Excel

ID: Q133135

The information in this article applies to:

• Microsoft Excel for Windows, versions 5.0, 5.0c
• Microsoft Excel for Windows NT, version 5.0
• Microsoft Excel for Windows 95, versions 7.0, 7.0a
• Microsoft Excel 97 for Windows
• Microsoft Excel for the Macintosh, versions 5.0, 5.0a
• Microsoft Excel 98 Macintosh Edition

SUMMARY

In Microsoft Excel, there is no direct method for sorting an array of values with a Microsoft Visual Basic for Applications macro or procedure. This article discusses two different algorithms that you can use to sort arrays: Selection Sort and Bubble Sort.

MORE INFORMATION

Microsoft provides programming examples for illustration only, without warranty either expressed or implied, including, but not limited to, the implied warranties of merchantability and/or fitness for a particular purpose. This article assumes that you are familiar with the programming language being demonstrated and the tools used to create and debug procedures. Microsoft support professionals can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific needs. If you have limited programming experience, you may want to contact the Microsoft fee-based consulting line at (800) 936-5200. For more information about the support options available from Microsoft, please see the following page on the World Wide Web:

   http://www.microsoft.com/support/supportnet/refguide/

Method 1: Selection Sort

To perform a Selection Sort of an array with 1...n elements, locate the largest element from 1...n. If this is not element n, then exchange the largest element with element n. Then, locate the largest element from 1...n-1 and, if this is not element n-1, exchange the largest element with element n-1. Next, locate the largest element from 1...n-2 and, if this is not element n-2, exchange the largest element with element n-2, and so on. Below is an example of a Selection Sort with a Visual Basic Variant type array.

1. Type the following in a module sheet:

      Option Base 1

      Function SelectionSort(TempArray As Variant)
          Dim MaxVal As Variant
          Dim MaxIndex As Integer
          Dim i, j As Integer

          ' Step through the elements in the array starting with the
          ' last element in the array.
          For i = UBound(TempArray) To 1 Step -1

              ' Set MaxVal to the element in the array and save the
              ' index of this element as MaxIndex.
              MaxVal = TempArray(i)
              MaxIndex = i

              ' Loop through the remaining elements to see if any is
              ' larger than MaxVal. If it is then set this element
              ' to be the new MaxVal.
              For j = 1 To i
                  If TempArray(j) > MaxVal Then
                      MaxVal = TempArray(j)
                      MaxIndex = j
                  End If
              Next j

              ' If the index of the largest element is not i, then
              ' exchange this element with element i.
              If MaxIndex < i Then
                  TempArray(MaxIndex) = TempArray(i)
                  TempArray(i) = MaxVal
              End If
          Next i

      End Function

      Sub SelectionSortMyArray()
          Dim TheArray As Variant

          ' Create the array.
          TheArray = Array("one", "two", "three", "four", "five", "six", _
              "seven", "eight", "nine", "ten")

          ' Sort the Array and display the values in order.
          SelectionSort TheArray
          For i = 1 To UBound(TheArray)
              MsgBox TheArray(i)
          Next i

      End Sub

   or Microsoft Excel 98, click the Tools menu, point to Macro, and then 
   click Macros.)

Method 2: Bubble Sort

To perform a Bubble Sort, evaluate 1...n-1 elements in the array where you compare each element with the one after it (element 1 is compared to element 2, element 2 is compared to element 3, and so on). If an element is larger than the element after it, then those two elements are exchanged. Continue this process until there are no more exchanges of elements. Below is an example of a Bubble Sort with a Visual Basic Variant type array.

1. Type the following in a module sheet:

      Option Base 1

      Function BubbleSort(TempArray As Variant)
          Dim Temp As Variant
          Dim i As Integer
          Dim NoExchanges As Integer

          ' Loop until no more "exchanges" are made.
          Do
              NoExchanges = True

              ' Loop through each element in the array.
              For i = 1 To UBound(TempArray) - 1

                  ' If the element is greater than the element
                  ' following it, exchange the two elements.
                  If TempArray(i) > TempArray(i + 1) Then
                      NoExchanges = False
                      Temp = TempArray(i)
                      TempArray(i) = TempArray(i + 1)
                      TempArray(i + 1) = Temp
                  End If
              Next i
          Loop While Not (NoExchanges)

      End Function

      Sub BubbleSortMyArray()
          Dim TheArray As Variant

          ' Create the array.
          TheArray = Array(15, 8, 11, 7, 33, 4, 46, 19, 20, 27, 43, 25, 36)

          ' Sort the Array and display the values in order.
          BubbleSort TheArray
          For i = 1 To UBound(TheArray)
              MsgBox TheArray(i)
          Next i
      End Sub

   or Microsoft Excel 98, click the Tools menu, point to Macro, and then 
   click Macros.)

MORE INFORMATION

NOTE: Both of these examples sort in ascending order. To perform a Selection Sort in descending order, change ">" to "<" in the following line of the SelectionSort function:

   If TempArray(j) > MaxVal Then

   If TempArray(i) > TempArray(i + 1) Then

Keywords          : kbprg kbdta kbdtacode PgmHowto KbVBA 
Version           : WINDOWS:5.0,5.0c,7.0,97; MACINTOSH:5.0,5.0a,98
Platform          : MACINTOSH WINDOWS
Issue type        : kbhowto

Last Reviewed: May 18, 1999