Question

I want to pass my set of objects and variables to VBA function, make some changes to it and pass it back as a result. So I create a sample Class1:

Public pInfo As String

and sample function:

Public Function populate(someVar As Class1) As Class1

    populate.pInfo = someVar.pInfo & " 1 "

End Function

and tryed to pass it to my function populate:

Sub test()
Dim v, w As Class1
Set v = New Class1
v.pInfo = "303"
Set w = populate(v) ' ERROR here

End Sub

results in compile error : byRef argument type mismatch.

UPDATE. Thanks to your help it compiles now.

Answer 1

Its a type error

Dim v, w As Class1

Unintuitively here only w is of type Class1, v is a variant.
To make them both Class1 you must:

Dim v As Class1, w As Class1

Here:

Public Function populate(someVar As Class1) As Class1
    populate.pInfo = someVar.pInfo & " 1 "
End Function

populate is not an instance of Class1, you need to create it:

Public Function populate(someVar As Class1) As Class1
    set populate = new Class1
    populate.pInfo = someVar.pInfo & " 1 "
End Function

(Rather than using a function you may prefer a v.copyTo(w))