Microsoft VBScript in Outlook uses only the Variant data type.
A Variant is a special kind of data type that can contain different kinds of information, depending on how it's used. Because Variant is the only data type in VBScript, it's also the data type returned by all functions in VBScript.
At its simplest, a Variant can contain either numeric or string information. A Variant behaves as a number when you use it in a numeric context and as a string when you use it in a string context. That is, if you're working with data that looks like numbers, VBScript assumes that it is numbers and does the thing that is most appropriate for numbers. Similarly, if you're working with data that can only be string data, VBScript treats it as string data. Of course, you can always make numbers behave as strings by enclosing them in quotation marks (" ").