How do I sort a collection?

Question

Does anyone know how to sort a collection in VBA?

Answer 1

This is my implementation of BubbleSort:

Public Function BubbleSort(ByRef colInput As Collection, _
                                    Optional asc = True) As Collection

    Dim temp                    As Variant
    Dim counterA                As Long
    Dim counterB                As Long

    For counterA = 1 To colInput.Count - 1
        For counterB = counterA + 1 To colInput.Count
            Select Case asc
            Case True:
                If colInput(counterA) > colInput(counterB) Then
                    temp = colInput(counterB)
                    colInput.Remove counterB
                    colInput.Add temp, temp, counterA
                End If

            Case False:
                If colInput(counterA) < colInput(counterB) Then
                    temp = colInput(counterB)
                    colInput.Remove counterB
                    colInput.Add temp, temp, counterA
                End If
            End Select
        Next counterB
    Next counterA

    Set BubbleSort = colInput

End Function

Public Sub TestMe()

    Dim myCollection    As New Collection
    Dim element         As Variant

    myCollection.Add "2342"
    myCollection.Add "vityata"
    myCollection.Add "na"
    myCollection.Add "baba"
    myCollection.Add "ti"
    myCollection.Add "hvarchiloto"
    myCollection.Add "stackoveflow"
    myCollection.Add "beta"
    myCollection.Add "zuzana"
    myCollection.Add "zuzan"
    myCollection.Add "2z"
    myCollection.Add "alpha"

    Set myCollection = BubbleSort(myCollection)

    For Each element In myCollection
        Debug.Print element
    Next element

    Debug.Print "--------------------"

    Set myCollection = BubbleSort(myCollection, False)

    For Each element In myCollection
        Debug.Print element
    Next element

End Sub

It takes the collection by reference, thus it can easily return it as a function and it has an optional parameter for Ascending and Descending sorting. The sorting returns this in the immediate window:

2342
2z
alpha
baba
beta
hvarchiloto
na
stackoveflow
ti
vityata
zuzan
zuzana
--------------------
zuzana
zuzan
vityata
ti
stackoveflow
na
hvarchiloto
beta
baba
alpha
2z
2342