# Indexed signatures are not supported Rule ``arkts-no-indexed-signatures`` **Severity: error** ArkTS does not allow indexed signatures. Use arrays instead. ## TypeScript ``` // Interface with an indexed signature: interface StringArray { [index: number]: string } function getStringArray() : StringArray { return ["a", "b", "c"] } const myArray: StringArray = getStringArray() const secondItem = myArray[1] ``` ## ArkTS ``` class X { public f: string[] = [] } let myArray: X = new X() const secondItem = myArray.f[1] ```