VBA: How to prevent duplicate entries in a UserForm list based on specific criteria?
I tried several approaches but none seem to work... I'm working on a UserForm in Excel VBA that allows users to input data into a list. The challenge I'm facing is ensuring that when a user tries to add a new entry, it's checked against existing entries to prevent duplicates based on a specific field (let's say 'Name'). I've implemented a simple check using a loop, but I'm encountering issues with it not functioning correctly under certain circumstances. Currently, my code for adding an entry looks like this: ```vba Private Sub btnAdd_Click() Dim newName As String newName = txtName.Value Dim isDuplicate As Boolean isDuplicate = False Dim i As Long For i = 2 To wsData.Cells(wsData.Rows.Count, 1).End(xlUp).Row If wsData.Cells(i, 1).Value = newName Then isDuplicate = True Exit For End If Next i If isDuplicate Then MsgBox "This name already exists!", vbExclamation Else wsData.Cells(wsData.Rows.Count, 1).End(xlUp).Offset(1, 0).Value = newName MsgBox "Name added successfully!" End If End Sub ``` Despite this approach, I find that duplicate entries can still be added occasionally if the input is slightly different in case (e.g., 'John Doe' vs. 'john doe'). I attempted to address this by modifying the comparison to: ```vba If UCase(wsData.Cells(i, 1).Value) = UCase(newName) Then ``` However, I'm still encountering situations where duplicates slip through, especially when there are leading or trailing spaces in the input. I've even tried using the `Trim` function, but it's not consistently effective. Could anyone suggest a more robust way to ensure that duplicates are effectively caught? Also, are there any best practices to follow when validating UserForm inputs in VBA to avoid these issues? What's the best practice here? This is part of a larger service I'm building. Am I missing something obvious?