Robust Bubble Sort in VBA

I'm creating a robust bubble sort for VBA when sorting stored arrays in VBA. Mostly this would be used when an array is stored in a single cell with a delimiter. Otherwise, one could just sort on the sheet during intake.

I'm trying to make this as robust as I can so it can be used as a tool rather than just continually rewriting it for each task when I need it. It can sort ascending or descending, the intention being that one may be able to use it to get minimums, maximums and medians.

I'd like to make it able to sort alphabetically, but right now it only sorts numbers. I mention this because I'd like to refactor the procedure that turns the variant array (hence the area with extra white space) into the double array, but I can't figure out an optimal way to do that without sending copies of arrays around, so it's just sitting in the TestBubbleSorting procedure right now. Any suggestions on that refactoring would be awesome.

Also, if the bubble sort method isn't the most robust sort algorithm to be using, I'd love to know that so I can try again.

Example input would be something like this

3
7,3,5
15,20,40
300,550,137

```
Option Explicit
Public Sub TestBubbleSorting()
Const DELIMITER As String = ","
Dim targetSheet As Worksheet
Set targetSheet = ActiveSheet
Dim numberOfArrays As Long
numberOfArrays = targetSheet.Cells(1, 1)
Dim rawArray As Variant
Dim arrayToSort() As Double
Dim targetRow As Long
Dim targetElement As Long
Dim numberOfElements As Long
Dim inputValue As String
Dim outputValue As String

For targetRow = 2 To numberOfArrays + 1
inputValue = targetSheet.Cells(targetRow, 1)
If Replace(inputValue, DELIMITER, vbNullString) = vbNullString Then GoTo NextIteration

rawArray = GetArrayFromCell(inputValue, DELIMITER)

numberOfElements = UBound(rawArray) + 1
ReDim arrayToSort(1 To numberOfElements)
For targetElement = 0 To numberOfElements - 1

In large I think the sort function is right out of the book of bubblesort.

IMO your naming is a little overdone. The long names are for an inexperienced eye hard to read.

The ascending and descending sort loops are essentially the same except for the direction of the comparation, so no need for backward loop or special temporary variables etc.

The swap mechanism calls for a swap function.

All in all find below a revised version of the sort function.

Private Sub Swap(vector() As Double, i As Long, j As Long)
    Dim tmp As Double
    tmp = vector(i)
    vector(i) = vector(j)
    vector(j) = tmp
End Sub

Private Sub BubbleSortNumbers(vector() As Double, Optional sortAscending As Boolean = True)
    Dim index As Long
    Dim isChanged As Boolean
    Dim first As Long
    Dim last As Long

    first = 1
    last = UBound(vector) - 1

    If sortAscending Then
        Do
            isChanged = False
            For index = first To last
                If vector(index) > vector(index + 1) Then
                    isChanged = True
                    Swap vector, index, index + 1
                End If
            Next index
            last = last - 1 ' The not yet positioned largest value "rabbits" down to its final position for every loop, so there is no need for checking it again.
        Loop While isChanged
    Else
        Do
            isChanged = False
            For index = first To last
                If vector(index) < vector(index + 1) Then
                    isChanged = True
                    Swap vector, index, index + 1
                End If
            Next index
            last = last - 1 
        Loop While isChanged
    End If
End Sub

All that said, bubble sort is not the most efficient algorithm, so if you have large data sets to sort I will suggest other more powerfull algorithms like quicksort, mergesort, heapsort or combsort where quicksort and combsort maybe are the easiest to implement (they are all well documented on Wikipedia).

StackExchange Code Review Q#145601, answer score: 3