# modifier(_:) Attach a `PreviewModifier` to the preview. ``` @MainActor static func modifier(_ modifier: some PreviewModifier) -> PreviewTrait ``` ## Discussion You can compose modifiers by passing more than one instance of this trait. Composed modifiers will be applied to the preview in order: the first modifier will apply to the body of the preview, the second modifier to the body of the first modifier, and so on. --- 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)