VarIsEmpty
Description
VarIsEmpty returns true if the given variant contains the value Unassigned. If the variant contains any other value, the function result is false.
Note: VarIsEmpty does not indicate when a Variant that represents an interface has had the interface pointer cleared or when a custom Variant is clear. If either of these situations may exist, use the VarIsClear method instead.
Note: Do not confuse an unassigned variant with a Null variant. A Null variant is still assigned, but has the value Null. Unlike unassigned variants, Null variants can be used in expressions and can be converted to other types of variants.
VarIsClear
Description
VarIsClear returns true if the given variant抯 value is undefined. The value can be undefined for any of several reasons:
The Variant may have had its value set to Unassigned.
The Variant抯 value may be an interface type that has been set to nil (Delphi) or NULL (C++).
The Variant may be a custom variant that returns true from its IsClear method.
In all other cases, the function result is false.
Note: Do not confuse an unassigned variant with a Null variant. A Null variant is still assigned, but has the value Null. Unlike unassigned variants, Null variants can be used in expressions and can be converted to other types of variants.
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