Conditionial Concatenation in VBA - arrays

Question

Short disclaimer: This is my very first question, so please be understanding.
I'm trying to code a function in Excel VBA that takes a binary number (formatted as a string) that counts the spaces, the 0s, and outputs the consecutive amount of 0s (and adds one to it) until the next "1" in that string appears, with "," in between. At the very end of the string, if there's the a "1", the output should look like: "..., 1". I'll try to make a little easier to understand with an example:
Strings of length twelve:
101011010101 --> 2, 2, 1, 2, 2, 2, 1
110000101101 --> 1, 5, 2, 1, 2, 1
100010001000 --> 4, 4, 4
So far I've managed to make a one-dimensional boolean array that takes the string and splits it into parts of length 1, so to say a "binary array". But I couldn't test it, since I only have half of the function.
Function ABSTAND(str As String, size As Integer) As String
Dim i As Integer
Dim arrays(size) As Boolean
For i = 1 To Len(str)
If Mid(str, i, 1) = "1" Then
arrays(i) = True
Else
arrays(i) = False
End If
'Maybe all of this works in a loop?
'Count consecutive 0s, add one
'Output the value with ", " (Concatenate numbers with strings, or make the number a string)
'Count consecutive 0s again
'and so on...
'Add conditions for the last value: Don't add a ", " and check if a one is the last character
End Function
I know, it looks like I have already figured out the problem and only need to implement it, but I'm new to VBA and don't know that well how it works and how to fix syntax and other problems.
Also, I would like to have a generalized form of my problem, that works with every string length, if that's possible.

Answer 1

Unfortunately, VBA isn't the best language for dealing with arrays. I've written the function as described but it sounds like, from your description, you might want to remove the check for If Len(arrZeroes(i)) > 0 Then etc. because it looks like you want to return '1' values in those cases.
Have a play around with the 'Split' function to try get a better feel for it and how it relates to your problem.
Function ABSTAND(str As String) As String
Dim arrZeroes() As String
Dim arrResult() As String
Dim i As Integer
'Initialise arrResult dimensions
ReDim arrResult(1 To 1)
'Splits your binary number into an array with each element being zero or more 0's
'(if there are several 1's in a row or a 1 at the start or finish it returns 0-length element for that position)
arrZeroes = Split(str, "1")
'Loop through each element in this new array
For i = LBound(arrZeroes) To UBound(arrZeroes)
'Sets the top element of the result array to this length + 1 then increments the size (like appending to array)
arrResult(UBound(arrResult)) = Len(arrZeroes(i)) + 1
ReDim Preserve arrResult(1 To UBound(arrResult) + 1)
Next i
'The last step on the result array incremented its ubound which is still empty so we remove that
ReDim Preserve arrResult(1 To UBound(arrResult) - 1)
'then return the array joined!
ABSTAND = Join(arrResult, ", ")
End Function
Let me know if anything doesn't make sense!
Edit:
An array is basically like an indexed list of elements of a specified data type. The line Dim arrZeroes() as String is dimming a dynamic array of string elements. The benefit of using a dynamic array is that you can dynamically change the amount of elements in it using Redim. To get around the lack of an 'append' function, what you have to do is redim the array to make it one element bigger then set this new biggest element to your new value.
arrResult(UBound(arrResult)) = Len(arrZeroes(i)) + 1
ReDim Preserve arrResult(1 To UBound(arrResult) + 1)
That's what these lines are doing. What the Split function does is, given a string and a delimiter, cut the string into a load of slices at each occurrence of the delimiter and return the array. For example, Split("11101101", "0") returns {"111", "11", "1"}. Where there are more than one occurrence of the delimiter in sequence, or the delimiter appears at the beginning or end of the string, it outputs a zero-length element, such as Split("101101", "1") returns {, "0", , "0",}. What the function is doing is looking at the length of each of these slices (i.e. consecutive digits that are not the delimiter) and outputting them to a new array.

Answer 2

Remove the # in your code.
It is used for preprocessing directive, and you do not need it.
More about Preprocessing directives:
https://msdn.microsoft.com/VBA/Language-Reference-VBA/articles/ifthenelse-directive
In general, try the following code:
Option Explicit
Public Sub TestMe()
Debug.Print ABSTAND("101011010101", 12)
End Sub
Function ABSTAND(str As String, size As Long) As String
Dim i As Long
Dim arrays() As Variant
Dim strResult As String
ReDim arrays(size)
For i = 1 To Len(str)
If Mid(str, i, 1) = "1" Then
arrays(i) = True
Else
arrays(i) = False
End If
strResult = strResult & arrays(i)
Next i
ABSTAND = strResult
End Function
It would print something like TrueFalseTrueFalseTrueTrue... Then try to build up your solution further.
Just some points:
Pay attention how the Array is created.
Use Long instead of Integer.
You can shorten the ABSTAND function, to the following:
Function ABSTAND(str As String, size As Long) As String
Dim i As Long
Dim arrays() As Variant
Dim strResult As String
ReDim arrays(size)
For i = 1 To Len(str)
arrays(i) = Mid(str, i, 1) = "1"
strResult = strResult & arrays(i)
Next i
ABSTAND = strResult
End Function