Visual Basic 6's Variant data type is able to hold any other
data type, including numbers, strings, dates, and object
references. This data type can be very useful in a wide variety
of situations. I'll show you a couple of useful tricks with
Variants. When a Variant has been declared but not assigned a
value, it contains the special value Empty. You can test for
this with the IsEmpty function. For example, suppose you want to
determine whether a Variant has been assigned a value. If it has
been assigned a value, you do nothing; if it hasn't been
assigned a value, then assign the value 0. Here's how (assume
that V is a type Variant variable): If IsEmpty(V) Then V = 0 If
an empty Variant is used in an expression, it will evaluate as
either the value 0 or an empty string depending on the
expression. Another useful special value is Null, which is
traditionally used to indicate that a variable does not contain
valid data. You can assign this value to a Variant with the Null
keyword: V = Null You can test for it wi