Is it possible to fill an array with row numbers which match a certain criteria without looping?

Question

I would like to fill an array in VBA with the row numbers of only rows which meet a certain criteria. I would like the fastest method possible (for example, something like <

Answer 1

I still have a loop, but only through the necessary rows to populate the array:

Sub get_row_numbers()

Dim RowArray() As Long
Dim valRange As Range
Dim valMatch As String

Set valRange = ActiveSheet.Range("A1:A11")
valMatch = "aa"
ReDim RowArray(WorksheetFunction.CountIf(valRange, valMatch) - 1)

Dim c As Range
Dim x As Integer
Set c = valRange.Find(What:=valMatch, LookIn:=xlFormulas, SearchOrder:=xlByRows, SearchDirection:=xlNext)

Do
  RowArray(x) = c.Row
  Set c = valRange.FindNext(after:=c)
  x = x + 1
Loop Until x = UBound(RowArray) + 1


End Sub

Answer 2

You may want to look at Find vs Match vs Variant Array which concludes that the variant array approach is fastest unless the hit density is very low.

But the fastest method of all is only for sorted data and exact match: use binary search to find the fisrt and last ocurrences and then get that subset of data into a variant array.