# insert(contentsOf:beforeIndex:) Adds the specified sequence of entities to this collection in order, directly before the entity at the given index. ``` mutating func insert(contentsOf sequence: S, beforeIndex index: Int) where S : Sequence, S.Element : Entity ``` ## Parameters `sequence` A sequence of entities to add to the collection. `index` The index of an entity to insert in front of. If `endIndex` is provided, the entities will be appended. ## Discussion> Note: This operation can invalidate the index order of any extant entities. --- 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)