Iterate over all rows and find the empty ones of active sheet VBA - excel

Question

I have an Excel-worksheet with different "sections" separated by an empty row. What I want to do is to simple get the row numbers to work with them. Sadly the code is not executing the For-Loop (No failure, just not entering it) but the rowNumber variable is set properly. Did I miss something on the For-Loop?
Sub Foo()
Dim currentSheet As Worksheet
Set currentSheet = activeSheet
emptyRows = FindAllEmptyRows(currentSheet)
End Sub
Function FindAllEmptyRows(sheet As Worksheet) As Variant
Dim emptyRows() As Variant
Dim i As Long, rowNumber As Long
Dim rowCounter As Integer
rowCounter = 1
rowNumber = sheet.UsedRange.Rows.Count
For i = rowNumber To 1
If Cells(i, 1).End(xlToRight).Column = 16384 And Cells(i, 1) = "" Then
emptyRows(rowCounter) = i
rowCounter = rowCounter + 1
End If
Next
FindAllEmptyRows = emptyRows
End Function

Answer 1

If you want to iterate from last row to first you will need to add Step -1.
emptyRows() needs to be sized to fit the data using ReDim
.Column = 16384 should be changed to .Column = sheet.Columns.Count.
I prefer If WorksheetFunction.CountA(sheet.Rows(i)) = 0 Then
Cells needs to be qualified to sheet: sheet.Cells(i, 1)
Refactored Code
Function FindAllEmptyRows(sheet As Worksheet) As Variant
Dim emptyRows() As Variant
Dim i As Long, rowNumber As Long
Dim rowCounter As Integer
rowNumber = sheet.UsedRange.Rows.Count
For i = rowNumber To 1 Step -1
If sheet.Cells(i, 1).End(xlToRight).Column = sheet.Columns.Count And Cells(i, 1) = "" Then
If rowCounter = 0 Then
ReDim emptyRows(0)
Else
ReDim Preserve emptyRows(rowCounter)
End If
emptyRows(rowCounter) = i
rowCounter = rowCounter + 1
End If
Next
FindAllEmptyRows = emptyRows
End Function
SpecialCells
Range.SpecialCells() can be used to divide a Range into areas of cells that meet certain criteria.
MSDN - Range.SpecialCells Method (Excel)
Returns a Range object that represents all the cells that match the specified type and value
OZ Grid
One of the most beneficial Methods in Excel (in my experience) is the SpecialCells Method. When used, it returns a Range Object that represents only those type of cells we specify. For example, one can use the SpecialCells Method to return a Range Object that only contains formulae. In fact, we can, if we wish, even narrow it down further to have our Range Object (containing only formulae) to return only formulae with errors.
Examining the output of this code should give you a good ideas of how to use SpecialCells.
Sub SpecialFoo()
Dim rArea As Range, rBlanks As Range, rFormulas As Range, rConstants As Range, rUnion As Range
Dim sheet As Worksheet
Set sheet = ActiveSheet
On Error Resume Next
Set rBlanks = sheet.UsedRange.SpecialCells(xlCellTypeBlanks)
On Error GoTo 0
If Not rBlanks Is Nothing Then
For Each rArea In rBlanks.Areas
Debug.Print "rBlanks Areas: "; rArea.Address
Next
End If
On Error Resume Next
Set rFormulas = sheet.UsedRange.SpecialCells(xlCellTypeFormulas)
On Error GoTo 0
If Not rFormulas Is Nothing Then
For Each rArea In rFormulas.Areas
Debug.Print "rFormulas Areas: "; rArea.Address
Next
End If
On Error Resume Next
Set rConstants = sheet.UsedRange.SpecialCells(xlCellTypeConstants)
On Error GoTo 0
If Not rConstants Is Nothing Then
For Each rArea In rConstants.Areas
Debug.Print "rConstants Areas: "; rArea.Address
Next
End If
If Not rFormulas Is Nothing And Not rConstants Is Nothing Then
Set rFormulas = Union(rConstants, rFormulas)
For Each rArea In rFormulas.Areas
Debug.Print "rUnion Areas: "; rArea.Address
Next
End If
End Sub

Answer 2

you have to size emptyRows() before using it
furthermore you could use WorksheetFunction.Count() to check for any value in current row
finally
Function FindAllEmptyRows(sheet As Worksheet) As Variant
Dim emptyRows() As Variant
Dim i As Long, rowNumber As Long, rowCounter As Long
With sheet.UsedRange ' reference passed sheet UsedRange
rowNumber = .Rows.Count
ReDim emptyRows(0 To rowNumber - 1) ' dim the array to the maximum possible size
For i = rowNumber To 1 Step -1 ' step through reference range rows from the last baxkwards to the first
If WorksheetFunction.Count(.Rows(i)) = 0 Then
emptyRows(rowCounter) = i + .Rows(1).Row - 1 ' fill array in current index with current row index
rowCounter = rowCounter + 1 ' update array index
End If
Next
End With
ReDim Preserve emptyRows(0 To rowCounter) ' redim the array according to the actual number of found empty rows
FindAllEmptyRows = emptyRows
End Function
please note that:
emptyRows(rowCounter) = i + .Rows(1).Row - 1
is storing the absolute row index, i.e. the sheet row index, while
emptyRows(rowCounter) = i
would store the relative row index, i.e. the row index withing the UsedRange, which may start from a row different than row 1