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Description
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Represents a variant of
VarType
1.
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Comments
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The
Null
value has special meaning indicating that a variable contains no data.
Most numeric operators return
Null
when either of the arguments is
Null
. This "propagation" of
Null
makes it especially useful for returning error values through a complex expression. For example, you can write functions that return
Null
when an error occurs, then call this function within an expression. You can then use the
IsNull
function to test the final result to see whether an error occurred during calculation.
Since variants are
Empty
by default, the only way for
Null
to appear within a variant is for you to explicitly place it there. Only a few functions return this value.
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Example
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Sub Main()
Dim a As Variant
a = Null
If IsNull(a) Then MsgBox "The variable is Null."
MsgBox "The VarType of a is: " & VarType(a) 'Should display 1.
End Sub
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CIMPLICITY