# init(base:separator:) Creates an iterator that presents the elements of the sequences traversed by `base`, concatenated using `separator`. ``` init(base: Base, separator: Separator) where Separator : Sequence, Separator.Element == Base.Element.Element ``` ## Discussion> Complexity: O(`separator.count`). --- 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)