VBA Vlookup across multiple sheets

Question

So I have two lists, each one in a different sheet. I'm checking that values in Sheet B are also in Sheet A. I'm using VLookup for this, the problem seems to be with the range statements, as this range appears to be 'empty'.

My VBA attempt is something like,

Dim lookupVal As String
Dim myString As String

For i = 1 to N
    lookupVal = Sheets("b").Cells(1 + i, 2)
    myString = Application.WorksheetFunction.VLookup(lookupVal, Sheets("a").range(Sheets("a").Cells(9,3), Sheets("a").Cells(N+8, 3)), 1, False)
    If IsEmpty(myString) Then
        Sheets("b").Cells(1+i, 3) = ""
    Else
        Sheets("b").Cells(1+i, 3) = myString
    End if

Next i

I get 'Run-time 1004: Application-defined or object-defined error'. Any help appreciated.

Answer 1

Change your code to the below.

If IsEmpty(myString) is the wrong way to do it. In case of #N/A , that statement will still be true.

Is this what you are trying?

Sub Sample()
    Dim lookupVal As String
    Dim myString As Variant
    Dim rng As Range

    '~~> Change this whatever you want
    n = 5

    For i = 1 To n
        lookupVal = Sheets("b").Cells(1 + i, 2)

        Set rng = Sheets("a").Range(Sheets("a").Cells(9, 3), Sheets("a").Cells(n + 8, 3))

        myString = Application.Evaluate("=VLOOKUP(" & lookupVal & "," & "a!" & rng.Address & ",1,0)")

        Select Case CVErr(myString)
            Case CVErr(xlErrName), CVErr(xlErrNA), CVErr(xlErrRef), CVErr(xlErrValue)
            Case Else: Sheets("b").Cells(1 + i, 3) = myString
        End Select
    Next i
End Sub

Answer 2

There are two problems in your code:

1. for worksheetfunction.vlookup the searching range cant be volatile. So the way to solve this issue is to use additional variable to do it permanent

2. if worksheetfunction.vlookup cannot find the searching value, then error will appear, in this case you need to use additional manipulation with error handling

3. lookupVal must be declared as Range due to format of the cells (lookup range and lookup value) can be different, but in your code cells value always will be converted into string type, and you will not be able to find numbers if they converted into string

4. myString also required to be declared as Variant due to same reason as described in "3." Type of the cell can be double for instance, but your code will convert it into string

so, your updated code is below, works fine

Sub test()
Dim lookupVal As Range, myString As Variant, Rng$, n&
n = Sheets("b").[B:B].Cells.Find("*", , , , xlByRows, xlPrevious).Row
On Error Resume Next
For i = 1 To n
    Set lookupVal = Sheets("b").Cells(1 + i, 2)
    Rng = Range(Cells(9, 3), Cells(n + 8, 3)).Address
    myString = WorksheetFunction.VLookup(lookupVal, Sheets("a").Range(Rng), 1, False)
    If Err.Number > 0 Then
        Sheets("b").Cells(1 + i, 3) = ""
        Err.Clear
    Else
        Sheets("b").Cells(1 + i, 3) = myString
    End If
Next i
End Sub

---

alternative way below

Sub test()
Dim cl As Range, Dic As Object
Set Dic = CreateObject("Scripting.Dictionary"): Dic.Comparemode = vbTextCompare
With Sheets("a")
    For Each cl In .Range("C9:C" & .Cells(Rows.Count, "C").End(xlUp).Row)
        If Not Dic.exists(cl.Value) Then Dic.Add cl.Value, cl.Row
    Next cl
End With
With Sheets("b")
    For Each cl In .Range("B2:B" & .Cells(Rows.Count, "B").End(xlUp).Row)
        If Dic.exists(cl.Value) Then cl.Offset(, 1).Value = cl.Value
    Next cl
End With
Set Dic = Nothing
End Sub