' Return the sum of the values in an array of any type' (for string arrays, it concatenates all its elements)'' FIRST and LAST indicate which portion of the array' should be considered; they default to the first' and last element, respectivelyFunction ArraySum(arr As Variant, Optional First As Variant, _    Optional Last As Variant) As Variant    Dim index As Long        If IsMissing(First) Then First = LBound(arr)    If IsMissing(Last) Then Last = UBound(arr)    For index = First To Last        ArraySum = ArraySum + arr(index)    NextEnd Function