# subscript(dynamicMember:) Returns a binding to the resulting value of a given key path. ``` subscript(dynamicMember keyPath: WritableKeyPath) -> Binding { get } ``` ## Parameters `keyPath` A key path to a specific resulting value. ## Return Value A new binding. ## Overview Use dynamic member lookup to project a property of the binding’s wrapped value from a key path into a new binding. The returned value is read from, and written to, the original binding. This can be useful when a view accepts a binding for a type that only matches a property of a value from an existing binding. For example, the `PlayerView` controls the current position for an episode using a `Slider`, and whether the episode is a favorite using a `Toggle`. The view projects the `currentPosition` and `isFavorite` properties of `Episode` into bindings that each of these views accept using dynamic member lookup. ``` struct Episode { var title: LocalizedStringKey var duration: TimeInterval var currentPosition: TimeInterval var isFavorite: Bool } struct PlayerView: View { @Binding var episode: Episode var body: some View { Text(episode.title) Toggle("Favorite", isOn: $episode.isFavorite) Slider( value: $episode.currentPosition, in: 0...episode.duration ) } } ``` --- 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)