# Private '#' identifiers are not supported Rule ``arkts-no-private-identifiers`` **Severity: error** ArkTS does not use private identifiers starting with the symbol ``#``. Use the keyword ``private`` instead. ## TypeScript ``` /* * Such notation for private fields is not supported in ArkTS: class C { #foo: number = 42 } */ ``` ## ArkTS ``` class C { private foo: number = 42 } ```