# append(contentsOf:) Appends the contents of a sequence to the end of the set, excluding elements that are already members. ``` mutating func append(contentsOf elements: some Sequence) ``` ## Parameters `elements` A finite sequence of elements to append. --- 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)