CombSort

Sub CombSort(arr As Variant, Optional numEls As Variant, Optional descending
As Boolean)
Dim value As Variant
Dim index As Long
Dim firstItem As Long
Dim Gap As Long
Dim Swap As Boolean

' account for optional arguments

If IsMissing(numEls) Then numEls = UBound(arr)
firstItem = LBound(arr)

Gap = numEls - firstItem + 1

Do While (Gap > 1 Or Swap)
' divide Gap by 1.3 - the author says it's an empirical value

Gap = (10 * Gap) \ 13
' another empirical value

If (Gap = 9 Or Gap = 10) Then Gap = 11
Swap = False
For index = firstItem To numEls - Gap
value = arr(index)
If (value > arr(index + Gap)) Xor descending Then
' if the items are not in order, swap them

arr(index) = arr(index + Gap)
arr(index + Gap) = value
Swap = True
End If
Next
Loop
End Sub

' Comb Sort an array of any type

'

' CombSort is faster than all but QuickSort and close to it.

' On the other hand, the code is much simpler than QuickSort

' and can be easily customized for any array type

' This routine is based on an article appeared on the Byte

' magazine in about 1985.

'

' NUMELS is the index of the last item to be sorted, and is

' useful if the array is only partially filled.

'

' Works with any kind of array, except UDTs and fixed-length

' strings, and including objects if your are sorting on their

' default property. String are sorted in case-sensitive mode.

'

' You can write faster procedures if you modify the first two lines

' to account for a specific data type, eg.

' Sub CombSortS(arr() As Single, Optional numEls As Variant,

' Optional descending As Boolean)

' Dim value As Single