How to create multi-dimensional array of unknown size? - arrays

Question

I've got a simple problem:
I've got a set of data, which I'm sifting through and adding into an array upon criteria match
Issue is, I don't know how many matches there might be, so I need the array to be of unspecified size.
The second index of the array is static.
In an (pseudo-language) example:
if <matched criteria> = True {
i = i + 1
array( i, 1 ) => "John Doe" ' name
array( i, 2 ) => "New York" ' location
array( i, 3 ) => "02. 08. 1992" ' birthdate
}
Issue is, in vba you have to kind of pre-declare the arrays (especially with Option Explicit enabled). My thought process was to declare an array, that would start with first index at 0 and I would gradually ReDim it upon need.
Here is an simplified example of my code:
Dim cell as Range
Dim arr(0, 1 to 3) as String
Dim i As Integer: i = 0
For each cell in Range("A1:A100")
If criteria_match(cell) = True Then
arr(i, 1) = Cells(cell.row, 4)
arr(i, 2) = Cells(cell.row, 5)
arr(i, 3) = Year(Cells(cell.row, 6))
i = i + 1
ReDim Preserve arr(i, 1 to 3)
End If
Next cell
Issue is, this throws an exception:
Is there perhaps any way, I could steadily increase the size of the first array index depending on the need?

Answer 1

Don't size the array in the variable declaration statement.
Change:
Dim arr(0, 1 to 3) as String
to:
Dim arr() as String
ReDim arr(1 to 3, i)
Redimension it as necessary.
Edit:
For more information, see this link: https://learn.microsoft.com/en-us/office/vba/language/reference/user-interface-help/array-already-dimensioned
To briefly summarize, when you size the array in the declaration statement, it creates a static array (which can't be resized). When you don't declare a size, then it becomes a dynamic array, which can be resized.
An important note to make: ReDim Preserve can only be applied on the last dimension of the array
eg. ReDim Preserve arr(1 to 3, i) will work.
Meanwhile, ReDim Preserve arr (i, 1 to 3) will not.

Answer 2

Use a Type for the data and a collection for the variables based on the type.
Class Person
Public Name As String
Public Location As String
Public DoB As Date
In a Module
Sub Test()
Dim this_person As Person
Dim Persons As Collection
Dim my_cell As Excel.Range
Set Persons = New Collection
For Each my_cell In Range("A1:A100")
If Criteria_Match(my_cell) Then
Set this_person = New Person
With this_person
.Name = ActiveWorkbook.ActiveWorksheet.Cells(my_cell.Row, 4).Value2
.Location = ActiveWorkbook.ActiveWorksheet.Cells(my_cell.Row, 5).Value2
.DoB = Year(ActiveWorkbook.ActiveWorksheet.Cells(my_cell.Row, 6).Value2)
End With
Persons.Add this_person
End If
Next
End Sub