RAD Studio VCL Reference
Variants.VarIsNull Function

Indicates whether the specified variant is Null.

function VarIsNull(const V: Variant): Boolean;
Boolean VarIsNull(const Variant V);

VarIsNull returns true if the given variant contains the value Null. If the variant contains any other value, the function result is false.

Note: Do not confuse a Null variant with an unassigned 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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