Handle Error 9 when there is an Empty Array

Question

I am writing a script that will loop through an Excel spreadsheet and find if there are duplicates of selected cells. If there are duplicates then the function will return

Answer 1

Is your array variant Empty or Empty()?

'Empty' is an uninitialised variant: IsEmpty(myVar) will return true... And you could be fooled into thinking you have an empty array (which is 'Empty()', not 'Empty' - try to keep up, there will be a short test after this class) because IsEmpty(myArray) returns True, too.

Dim myVar as Variant      ' this is currently Empty, and Ubound returns an error

Dim myArray() as variant  ' this is currently Empty(), and Ubound returns an error  


Redim myVar(0 to 0)   ' this is no longer empty, and has a valid Ubound

Redim myArray(0 to 0) ' this is no longer empty, and has a valid Ubound

A reliable way to check myVar is TypeName(myVar) - if it's an array, the name contains brackets:

  
If Instr(Typename(myVar), "(") > 0 then  

    ' we now know it is an array  
    If Not IsEmpty(myVar) Then  

       ' We can now check its dimensions  
        If Ubound(myVar) > 0  
             ' insert error-free code here  
        Endif  

    Endif  

Endif  

The full answer is 'Detecting an array variant in Excel VBA' on Excellerando.