Type Dictionary
    As String key
    As String value
End Type

Sub merge(original() As Dictionary, update() As Dictionary, result() As Dictionary)
    Dim As Integer i, j, index
    Dim As Boolean found

    For i = 0 To Ubound(update)
        result(i) = update(i)
    Next i

    index = i
    For i = 0 To Ubound(original)
        found = False
        For j = 0 To Ubound(update)
            If original(i).key = update(j).key Then
                found = True
                Exit For
            End If
        Next j
        If Not found Then
            result(index) = original(i)
            index += 1
        End If
    Next i
End Sub

Dim As Dictionary original(2)
original(0).key = "name": original(0).value = "Rocket Skates"
original(1).key = "price": original(1).value = "12.75"
original(2).key = "color": original(2).value = "yellow"

Dim As Dictionary update(2)
update(0).key = "price": update(0).value = "15.25"
update(1).key = "color": update(1).value = "red"
update(2).key = "year": update(2).value = "1974"

Dim As Dictionary merged(Ubound(update) + Ubound(original) - 1)
merge(original(), update(), merged())

For i As Integer = 0 To Ubound(merged)
    Print "key: "; merged(i).key; ", value: "; merged(i).value
Next i

Sleep