redimension multidimensional arrays in Excel VBA - excel

Question

Take a look at the following code. What my problem is is that I can't figure out how to redimension the n integer and the b integer. What I'm doing is the array sent1 is already working and it is populated with about 4 sentences. I need to go through each sentence and work on it but I'm having trouble.
dim sent1()
dim sent2()
dim n as integer, b as integer, x as integer
dim temp_sent as string
b = 0
For n = 1 to ubound(sent1)
temp_sent = sent1(n)
for x = 1 to len(temp_sent1)
code
if a then
b = b + 1
'**THIS IS THE PART OF THE CODE THAT IS NOT WORKING**
redim preserve sent2(1 to ubound(sent1), b)
sent2(n,b) = [code]
next
next

Answer 1

There are two issues in your code:
When you Dim an array without specifying the lower bound it will by default be 0 based (unless you have specified Option Base 1). When explicitly specified, lower bound can be any number, not just 0 or 1
For a multi dimensioned array, Redim Preserve can only change the last dimension, and then only the upper bound.
In general, I find it better to always specify Lower and Upper bounds, eg
Redim MyArray(1 to 10, 0 to 99)

Answer 2

Is there any specific reason why you want to / must use arrays?
If not, I'd suggest using collections instead. You can also have nested collections, e.g.
Dim dimension1 As New Collection
Dim dimension2 AS New Collection
dimension1.Add dimension2
etc.
That way, you won't have to worry about increasing dimensions manually at all. If you need to convert it back to a 2D Array, you can do sth like this in the end
Dim item AS Variant
Dim subCollection AS Collection
Dim nRows AS Integer
Dim nCols AS integer
' assuming "col" is your jagged collection
nRows = col.Count
For Each item in col
If TypeOf item is Collection
Set subCollection = item
If subCollection.Count > nCols Then
nCols = subCollection.Count
End If
Next item
Next item
Dim result(nRows, NCols) As Variant
' Now loop through the collections again and fill the result array

Answer 3

The problem that you have is that you cannot change the rank (dimensions) of an array with a redim statement.
dim sent() creates a 1-rank array, redim sent2(x, y) assumes a 2-rank array. Try dim sent(,).
Also, it will improve performance (and code robustness) if you use
dim sent1() as string
dim sent2(,) as string

Answer 4

In case anyone has this problem here is how I solved it:
<code>
Function find_sentences_complex(instring As String) As Variant
Dim xorr As String: xorr = ChrW(&H22BB)
Dim triple_bar As String: triple_bar = ChrW(&H2261)
Dim idisj As String: idisj = ChrW(&H2228)
Dim cond As String: cond = ChrW(&H2192)
Dim x As Integer, y As Integer, z As Integer, b As Integer
Dim total As Integer, paren_closure As Integer, marker As Boolean
Dim n As Integer
Dim sent1() As Variant, sent3() As Variant
'Dim final1d As Integer, final2d As Integer
Dim b_arr() As Integer
Dim b_max As Integer
Dim temp_string As String
For x = InStr(instring, "(") To Len(instring) Step 1
temp_string = Mid(instring, x, 1)
If Mid(instring, x, 1) = "(" Then
If marker = False Then
z = x
marker = True
End If
total = total + 1
ElseIf Mid(instring, x, 1) = ")" Then
total = total - 1
If total = 0 Then
marker = False
b = b + 1
paren_closure = x
ReDim Preserve sent1(b)
sent1(b) = Mid(instring, z, (x - z) + 1)
End If
End If
Next
Dim temp_sent1 As String
total = 0
marker = False
b = 0
Dim sent2()
ReDim sent2(UBound(sent1), 5)
For n = 1 To UBound(sent1)
temp_sent1 = sent1(n)
temp_sent1 = Mid(temp_sent1, 2, Len(temp_sent1) - 2)
b = 0
For x = 1 To Len(temp_sent1)
temp_string = Mid(instring, x, 1)
If Mid(temp_sent1, x, 1) = "(" Then
If marker = False Then
z = x
marker = True
End If
total = total + 1
ElseIf Mid(temp_sent1, x, 1) = ")" Then
total = total - 1
If total = 0 Then
marker = False
b = b + 1
paren_closure = x
'ReDim Preserve sent2(n, b)
sent2(n, b) = Mid(temp_sent1, z, (x - z) + 1)
End If
End If
Next
'this part of the code redimensions the side of the array
ReDim Preserve b_arr(n)
b_arr(n) = b
Next
b_max = MaxValOfIntArray(b_arr)
ReDim Preserve sent2(UBound(sent1), b_max)
End Function
Public Function MaxValOfIntArray(ByRef TheArray As Variant) As Integer
'This function gives max value of int array without sorting an array
Dim i As Integer
Dim MaxIntegersIndex As Integer
MaxIntegersIndex = 0
For i = 1 To UBound(TheArray)
If TheArray(i) > TheArray(MaxIntegersIndex) Then
MaxIntegersIndex = i
End If
Next
'index of max value is MaxValOfIntArray
MaxValOfIntArray = TheArray(MaxIntegersIndex)
End Function
</code>