Search for specific string in an Excel Workbook - vba

Question

So, I need to make an Excel Macro in VBA that will search for a string, then compare it with a pre-set string of my choice and then change the value of a cell in another Sheet.
It goes like this:
Sub Macro1()
Dim A As Integer
Dim WS As Worksheet
Dim ToCompare, Coniburo As String
Coniburo = "My String"
For Each WS In Worksheets
For A = 1 To Rows.Count
ToCompare = Left(Cells(A, 3), 100)
If InStr(ToCompare, Coniburo) > 0 Then
Sheets("Last Sheet").Cells(21, 2).Value = "233"
End If
Next A
Next
The macro works....... If I remove the first For (the one that search through sheets) and as long as I'm in a sheet where "My string" is present. Otherwise, it doesn't work. It takes a long time to process, over a minute since there are 17 sheets.
Why isn't working? I read a lot of posts here, the Microsoft Dev forum, a site called Tech on the Net, and still there is something I'm missing, but I don't know why.
Can anybody point me in the right direction?

Answer 1

Use a With ... End With to focus the parent worksheet for each iteration of the loop.
Option Explicit
Sub Macro1()
Dim a As Long, Coniburo As String, ws As Worksheet
Coniburo = "My String"
For Each ws In Worksheets
With ws
For a = 1 To .Cells(.Rows.Count, "C").End(xlUp).Row
If CBool(InStr(Left(.Cells(a, 3), 100), Coniburo, vbTextCompare)) Then
Worksheets("Last Sheet").Cells(21, 2).Value = 233
End If
Next a
End With
Next
End Sub
You need to prefix Rows, Range and Cells calls with a period like .Rows... or .Range(...) or .Cells(...) when inside a With ... End With block. This identifies them with the parent worksheet described by the With .. End With.
I also made the comparison case-insensitive with vbTextCompare.
There is the remaining problem of writing and rewriting 233 into the same cell on the same worksheet but that is another matter.

Answer 2

I've bent the rules a little here but I want to show how we could use the built in FIND function to speed things up dramatically. Simply, we'll work through each sheet within column C only; we'll use the FIND function to find the ROW number where column C contains your search string.... then we'll double-check that cell to see if your search string is within the first 100 characters, per your requirement. If it is, we'll consider that a match. In addition to your result of logging "233" into the sheet "Last Page" I've included some bright green highlighting just to help see what's going on...
Sub findConiburo()
Coniburo = "My String"
For Each ws In Worksheets
With ws.Range("C:C")
myName = ws.Name 'useful for debugging
queue = 1 'will be used to queue the FIND function
x = 0 'loop counter
Do 'loop to find multiple results per sheet
On Error Resume Next 'Disable error handling
'FIND Coniburo within ws column C, log row number:
'Note ".Cells(queue, 1)" is a relative reference to the current WS, column C
foundRow = .Find(What:=Coniburo, After:=.Cells(queue, 1), LookIn:=xlFormulas, LookAt _
:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, MatchCase:= _
False, SearchFormat:=False).Row
'If no result found then an error number is stored. Perform error handling:
If Err.Number <> 0 Then
'No results found, don't do anything, exit DO to skip to next sheet:
Exit Do
End If
On Error GoTo 0 'Re-enable error handling
If x = 0 Then
'first loop - log the first row result:
originalFoundRow = foundRow
ElseIf foundRow = originalFoundRow Then
'Not the first loop. Same result as original loop = we're back at the start, so exit loop:
Exit Do
End If
'Update queue so next loop will search AFTER the previous result:
queue = foundRow
'check if the string is not only SOMEWHERE in the cell,
'but specifically within the first 100 characters:
ToCompare = Left(.Cells(foundRow, 1), 100)
If InStr(ToCompare, Coniburo) > 0 Then
.Cells(foundRow, 1).Interior.ColorIndex = 4 'highlight green
Sheets("Last Sheet").Cells(21, 2).Value = "233"
End If
'Update loop counter:
x = x + 1
Loop
End With
Next ws
End Sub