This probably doesn't apply to your situation, but **IF** your A1, A2 and
Result arrays are **ALL** declared as being String arrays, you can perform
the combining of them in a single line of code...
Result = Split(Join(A1, Chr(1)) & Chr(1) & Join(A2, Chr(1)), Chr(1))
The resulting Result array will always be zero-based no matter what your
Option Base setting is (the Split function always produces zero-based
arrays). But remember, the above single line of code applies only if the
arrays are declared as Strings. For example...
Sub Test
Dim A1() As String
Dim A2() As String
Dim Result() As String
A1 = Split("1 2 3")
A2 = Split("4 5 6 7 8")
Result = Split(Join(A1, Chr(1)) & Chr(1) & Join(A2, Chr(1)), Chr(1))
Debug.Print UBound(Result)
End Sub
Note that in use, the elements of Result can still be used in calculations
as VB's behind-the-scenes automatic coercion would turn the numerical String
values into real numbers in order to perform the calculations.