Function to return 2 arrays as output

A function can return two arrays, by using a ByRef argument.

Sub test()
    Dim firstReturn As Variant
    Dim secondReturn As Variant

    firstReturn = myFtn("x", secondReturn)
    
    MsgBox Join(firstReturn) & vbCr & Join(secondReturn)
End Sub


Function myFtn(aString As String, Optional ByRef secondArray As Variant) As Variant
    Dim Result1(1 To 3)   As String
    Dim Result2(1 To 3) As String
    Dim i As Long
    For i = 1 To 3: Result1(i) = aString & i: Next i
    For i = 1 To 3: Result2(i) = i & aString: Next i
    
    myFtn = Result1
    secondArray = Result2
End Function