VBA Forloop/ Do until-CodePudding

Just needed some help in understanding forloop implementation.

Here is my failed attempt:

Sub test()

   Do Until IsEmpty(Worksheets("do not open!").Range("F1"))
         If UI.ComboBoxSource <> ActiveCell Then
         MsgBox "This procedure already exhists. Please click on update summary. "
         Else
         End If
         Worksheets("do not open!").Range("F1").Offset(1, 0).Select
         Loop


End Sub

Here is the correct attempt by @FaneDuru:

    Sub test()
  Dim ws As Worksheet, rngF As Range
  
  Set ws = Worksheets("do not open!")
  Set rngF = ws.Range("F1")
   
   Do Until rngF.Value = ""
         If UI.ComboBoxSource <> rngF.Value Then
            MsgBox "This procedure already exhists. Please click on update summary. "
         Else 
            'do something...
         End If
         Set rngF = rngF.Offset(1)
  Loop

End Sub

I am trying to loop trough a range of cells (F1 downwards in this case until blank cells), and applying the if statement to compare if the values match. If the values match, then I want the loop to continue till the end...If there is a mismatch, then I want the MsgBox to appear and stop the loop.

This is what I tried to do:

Sub check_procedures()
  Dim ws As Worksheet, rngF As Range
  
  Set ws = Worksheets("do not open!")
  Set rngF = ws.Range("F1")
   
   Do Until rngF.Value = ""
         If UI.ComboBoxSource = rngF.Value Then
         MsgBox "This procedure already exhists. Please click on Update Summary. "
         Exit Sub
         
         
         Else
         End If
            
            
         Set rngF = rngF.Offset(1)
         
         
    
    Loop
    
End Sub

Thanks for the help with this.

CodePudding user response：

Please, try the next way. Selecting, activating only consumes Excel resources, without bringing any benefit:

Sub test()
  Dim ws As Worksheet, rngF As Range
  
  Set ws = Worksheets("do not open!")
  Set rngF = ws.Range("F1")
   
   Do Until rngF.Value = ""
         If UI.ComboBoxSource <> rngF.Value Then
            MsgBox "This procedure already exhists. Please click on update summary. "
         Else 
            'do something...
         End If
         Set rngF = rngF.Offset(1)
  Loop

End Sub

But the code looks strange as logic. It will send a lot of messages. What to be done when UI.ComboBoxSource = rngF.Value? Should all cell values in F:F be equal with UI.ComboBoxSource and only by accident one, or two will not be? If only one, you should place Exit Do after, to make the code faster, not iterating up to the first empty cel...