Adjacent number algorithm grouper

Question

By which I mean this:

Given the input set of numbers:

1,2,3,4,5 becomes \"1-5\".

1,2,3,5,7,9,10,11,12,14 becomes \"1-3, 5, 7, 9-12, 14\"

This is

Answer 1

VBA

Public Function convertListToRange(lst As String) As String
    Dim splLst() As String
    splLst = Split(lst, ",")
    Dim x As Long
    For x = 0 To UBound(splLst)
        Dim groupStart As Integer
        groupStart = splLst(x)
        Dim groupEnd As Integer
        groupEnd = groupStart
        Do While (x <= UBound(splLst) - 1)
            If splLst(x) - splLst(x + 1) <> -1 Then Exit Do
            groupEnd = splLst(x + 1)
            x = x + 1
        Loop
        convertListToRange = convertListToRange & IIf(groupStart = groupEnd, groupStart & ",", groupStart & "-" & groupEnd & ",")
    Next x
    convertListToRange = Left(convertListToRange, Len(convertListToRange) - 1)
End Function

convertListToRange("1,2,3,7,8,9,11,12,99,100,101")
Return: "1-3,7-9,11-12,99-101"