# subscript(_:) Reads and writes values associated with a given focused value key. ``` subscript(key: Key.Type) -> Key.Value? where Key : FocusedValueKey { get set } ``` ## Overview Use this subscript to get or set a focused value for a custom [`FocusedValueKey`](/documentation/SwiftUI/FocusedValueKey). In most cases, you’ll use the `Entry` macro to create focused value properties, which automatically generates the appropriate key and uses this subscript internally: ``` extension FocusedValues { @Entry var myCustomValue: MyType? } ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)