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VarType

function VarType(const V: Variant): TVarType;

Example​

procedure ScriptEvent(var Value: variant);
var
  Items: Variant;
  Kind: TVarType;
begin
  Items := VarArrayCreate(2, varInteger);
  Kind := VarType(Items);
  Value := (Kind and varArray) <> 0; // True
end;

Usage​

VarType returns the raw Word type code of a Variant, including array and by-reference flags.

Parameters and result

ItemTypeDescription
VVariant (const)Variant whose top-level stored type code is required. No conversion is performed.
ResultTVarTypeRaw Word type code, including base type and any array/by-reference flags.

Additional Technical Info​

VarType returns the raw TVarData.VType code stored in V. The result contains a base Variant type and can also contain the varArray and varByRef flag bits.

The example is fictional and source-reviewed only.

Implementation

The modified PascalScript runtime registers Delphi System.Variants.VarType directly. The installed Delphi implementation returns TVarData(V).VType without dereferencing or masking it.

This raw behaviour is important. The missing-value predicates resolve underlying Variant indirection before comparing with varEmpty or varNull; VarType instead reports the top-level representation that the caller supplied.

Interpreting the result

ComponentMeaning
Kind and varTypeMaskBase type code, such as varEmpty, varNull, varInteger, varDate, varOleStr, varVariant or a custom type code.
(Kind and varArray) <> 0The Variant contains Automation array storage.
(Kind and varByRef) <> 0The Variant contains a by-reference representation.

An exact equality check such as VarType(V) = varInteger is appropriate only when flags must be absent. For an integer Variant array, the raw result is varInteger or varArray, so mask the base code and test the array flag separately.

Edge cases and quirks

  • VarType(Unassigned) is varEmpty; VarType(Null) is varNull.
  • A varVariant wrapper and a by-reference Variant can report their wrapper/flag type rather than the resolved payload type.
  • Custom Variant type codes are returned unchanged; this function does not ask the custom handler for a more general category.
  • Type inspection says nothing about semantic validity. An empty string, zero, false, nil interface and invalid business date can each have a normal non-Empty type code.
  • Type codes are implementation identifiers, not stable text-format values. Do not persist them as a cross-language schema without an explicit contract.

Side effects, errors, performance and concurrency

The routine reads one type field. It allocates nothing, performs no I/O or conversion, does not invoke custom handlers and has no normal exception path. It is constant-time. The same Variant must not be mutated concurrently while its representation is being inspected.

Related entries

External references

Created 2026-07-15