VBA Recursive loop for columns - excel

Question

Can anyone explain me if I can recursively loop through a sorted list inside a For loop?
I am looping through a column, and once I found an exact match (lets say EALOLES string), then I want to keep on looping until there's no more matches.
Data example
For i = 2 to UsedRange.Rows.Count
If (Cells(i, 12).Value = "EALOLES") Then
' Start an inner loop until EALOLES ends, increment i++
' Perform actions appropriate to EALOLES case
Exit For
End If
next i
This is all fine with an inner loop, but I was just wondering if this could be achieved also with a recursive function and how that would look like? From the example I learned about recursion, I would imagine to loop from end of workbook to the beginning.
Note, I am not stating it would be a better solution, neither an inner loop, but I am just very curious.

Answer 1

Your question is basically is this a candidate for recursion, and the answer is no. Iteration with your inner loop is the better solution in this case.
Read the article: Recursion and Iteration to learn when to use each.

Answer 2

Assuming your data are sorted, you could take advantage of that
Dim nOccurrences As Long
Dim cell As Range
With Intersect(ActiveSheet.UsedRange, Columns(12))
nOccurrences = WorksheetFunction.CountIf(.Cells, "EALOLES")
If nOccurrences > 0 Then
For Each cell in .Resize(nOccurrences).Offset(.Find(What:= "EALOLES", LookIn:=xlValues, LookAt:=xlWhole, After:=.Cells(.Rows.Count)).Row-1)
‘Do your things
Next
End If
End With

Answer 3

This is not an efficient method of returning the start and stop positions of a string in a sorted list but as an intellectual excercise this should do.
dim i as long, j as long
For i = 2 to UsedRange.Rows.Count
If (Cells(i, 12).Value = "EALOLES") Then
for j=i to UsedRange.Rows.Count
If (Cells(j+1, 12).Value <> "EALOLES") Then
exit for
end if
next j
Exit For
End If
next i
debug.print "start: " & i
debug.print "end: " & j

Answer 4

I was musing with a slightly different take on the same theme
Define a range to loop over. See if the value exists in the range. If it does, start at the first match and keep looping the loop range until the cell value differs from the specified target string.
Option Explicit
Sub StopAtEnd()
Dim wb As Workbook
Dim ws As Worksheet
Dim endRow As Long
Set wb = ThisWorkbook
Set ws = wb.Worksheets("Sheet5") 'change as needed
endRow = ws.Cells(ws.Rows.Count, "L").End(xlUp).Row
Dim loopRange As Range
Set loopRange = ws.Range("L1:L" & endRow) 'Change start row as required
Dim currentCell As Range
Dim targetString As String
Dim startRow As Long
targetString = "EALOLES"
On Error GoTo Errhand
startRow = Application.Match(targetString, loopRange, 0)
Do Until ws.Range("L" & startRow) <> targetString
Debug.Print ws.Range("L" & startRow).Address
startRow = startRow + 1
Loop
Exit Sub
Errhand:
MsgBox "Target string not found"
End Sub
Shout out to #DisplayName who pointed out this could be written instead as:
Option Explicit
Sub StopAtEnd()
Dim wb As Workbook
Dim ws As Worksheet
Dim endRow As Long
Set wb = ThisWorkbook
Set ws = wb.Worksheets("Sheet1") 'change as needed
endRow = ws.Cells(ws.Rows.Count, "L").End(xlUp).Row
Dim loopRange As Range
Set loopRange = ws.Range("L1:L" & endRow) 'Change start row as required
Dim currentCell As Range
Dim targetString As String
Dim startRow As Variant
targetString = "EALOLES"
startRow = Application.Match(targetString, loopRange, 0)
If IsError(startRow) Then
MsgBox "Target string not found"
Else
Do Until ws.Range("L" & startRow) <> targetString
Debug.Print ws.Range("L" & startRow).Address
startRow = startRow + 1
Loop
End If
End Sub