XL: Using a Visual Basic Macro to Sort Arrays in Microsoft Excel
ID: Q133135
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The information in this article applies to:
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Microsoft Excel for Windows, versions 5.0, 5.0c
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Microsoft Excel for Windows NT, version 5.0
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Microsoft Excel for Windows 95, versions 7.0, 7.0a
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Microsoft Excel 97 for Windows
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Microsoft Excel for the Macintosh, versions 5.0, 5.0a
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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/overview/overview.asp 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.
- 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
- To run the macro, click Macro on the Tools menu. (In Microsoft Excel 97
or Microsoft Excel 98, click the Tools menu, point to Macro, and then
click Macros.)
- Select the SelectionSortMyArray macro, and click Run.
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.
- 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
- To run the macro, click Macro on the Tools menu. (In Microsoft Excel 97
or Microsoft Excel 98, click the Tools menu, point to Macro, and then
click Macros.)
- Select the SelectionSortMyArray macro, and click Run.
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
To perform a Bubble Sort in descending order, change ">" to a "<" in the
following line of the BubbleSort function:
If TempArray(i) > TempArray(i + 1) Then
Additional query words:
5.00a 5.00c 8.00 XL98 XL97 XL7 XL5
Keywords : kbprg kbdta kbdtacode PgmHowto KbVBA
Version : MACINTOSH:5.0,5.0a,98; WINDOWS:5.0,5.0c,7.0,7.0a,97; winnt:5.0
Platform : MACINTOSH WINDOWS winnt
Issue type : kbhowto
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