System.Variants.NullEqualityRule
Delphi
NullEqualityRule: TNullCompareRule = ncrLoose;
C++
extern DELPHI_PACKAGE TNullCompareRule NullEqualityRule;
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
| variable | public | System.Variants.pas System.Variants.hpp |
System.Variants | System.Variants |
Description
Specifies rule for Null variant equality comparison.
NullEqualityRule determines the rule for handling equality comparisons (equals or not-equals) when one of the values compared is a variant containing a null value. NullEqualityRule can have the following values:
| Constant | Meaning |
|---|---|
|
ncrLoose |
(Default.) A variant containing a null is treated as a unique value that is only equal to another variant containing a null. |
|
ncrStrict |
An equality comparison of a variant containing a null is always false, regardless of the other value. |
|
ncrError |
An equality comparison raises an EVariantInvalidNullOpError if either value is a variant containing a null. |