# tag(_:includeOptional:) Sets the unique tag value of this view. ``` @export(implementation) nonisolated func tag(_ tag: V, includeOptional: Bool = true) -> some View where V : Hashable ``` ## Parameters `tag` A value to use as the view’s tag. `includeOptional` If the tag value for `Optional` should also be set. ## Return Value A view with the specified tag set. ## Discussion Use this modifier to differentiate among certain selectable views, like the possible values of a [`Picker`](/documentation/SwiftUI/Picker) or the tabs of a [`TabView`](/documentation/SwiftUI/TabView). Tag values can be of any type that conforms to the protocol. This modifier will write the tag value for the type `V`, as well as `Optional` if `includeOptional` is enabled. Containers checking for tags of either type will see the value as set. In the example below, the [`ForEach`](/documentation/SwiftUI/ForEach) loop in the [`Picker`](/documentation/SwiftUI/Picker) view builder iterates over the `Flavor` enumeration. It extracts the string value of each enumeration element for use in constructing the row label, and uses the enumeration value as input to the `tag(_:)` modifier. ``` struct FlavorPicker: View { enum Flavor: String, CaseIterable, Identifiable { case chocolate, vanilla, strawberry var id: Self { self } } @State private var selectedFlavor: Flavor? = nil var body: some View { Picker("Flavor", selection: $selectedFlavor) { ForEach(Flavor.allCases) { flavor in Text(flavor.rawValue) .tag(flavor) } } } } ``` The selection type of the [`Picker`](/documentation/SwiftUI/Picker) is an `Optional` and so it will look for tags on its contents of `Optional` type. Since the tag modifier defaults to having `includeOptional` enabled, even though the tag for each option is a non-optional `Flavor`, the tag modifier writes values for both the non-optional, and optional versions of the value, allowing the contents to be selectable by the [`Picker`](/documentation/SwiftUI/Picker). A [`ForEach`](/documentation/SwiftUI/ForEach) automatically applies a default tag to each enumerated view using the `id` parameter of the corresponding element. If the element’s `id` parameter and the picker’s `selection` input have exactly the same type, or the same type but optional, you can omit the explicit tag modifier. To see examples that don’t require an explicit tag, see [`Picker`](/documentation/SwiftUI/Picker). --- 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)