Function to Validate Headers

We've all been there, you've been downloading the same csv for the last 6 months every single damn day and blindly loading it into your model with every belief it's not going to change and bang, a workbook full of errors or your VBA falls over.

Save yourself the misery and make sure that you validate that your field headers haven't changed. Here's how:

Function ValidateHeaders(ByRef varRequiredHeaders As Variant, ByRef rngFoundHeaders As Range, Optional ByRef blnCheckOrder = False) As Boolean

    Dim lngHeader As Long
    Dim varMatches As Variant
    
    varMatches = Application.Match(varRequiredHeaders, rngFoundHeaders, 0)
    ValidateHeaders = Application.CountA(varRequiredHeaders) = _
                      Application.Count(varMatches)
                      
    If blnCheckOrder And ValidateHeaders Then
        For lngHeader = LBound(varMatches) To UBound(varMatches)
            If varMatches(lngHeader) <> lngHeader Then
                ValidateHeaders = False
                Exit Function
            End If
        Next lngHeader
    End If
    
End Function

This function will work within the Excel Grid or as part of your VBA and will return a Boolean result (TRUE or FALSE) to report it's success or failure.

Simply pass an array or a range of cells into the first two parameters and an optional TRUE in the blnCheckOrder parameter if field order is important and boom, immediate validation.