# +(_:_:) Creates a new collection by concatenating the elements of a collection and a sequence. ``` static func + (lhs: Self, rhs: Other) -> Self where Other : Sequence, Self.Element == Other.Element ``` ## Parameters `lhs` A range-replaceable collection. `rhs` A collection or finite sequence. ## Discussion The two arguments must have the same `Element` type. For example, you can concatenate the elements of an integer array and a `Range` instance. ``` let numbers = [1, 2, 3, 4] let moreNumbers = numbers + (5...10) print(moreNumbers) // Prints "[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]" ``` The resulting collection has the type of the argument on the left-hand side. In the example above, `moreNumbers` has the same type as `numbers`, which is `[Int]`. --- 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)