# +=(_:_:) Appends the elements of a sequence to a range-replaceable collection. ``` static func += (lhs: inout Self, rhs: Other) where Other : Sequence, Self.Element == Other.Element ``` ## Parameters `lhs` The array to append to. `rhs` A collection or finite sequence. ## Discussion Use this operator to append the elements of a sequence to the end of range-replaceable collection with same `Element` type. This example appends the elements of a `Range` instance to an array of integers. ``` var numbers = [1, 2, 3, 4, 5] numbers += 10...15 print(numbers) // Prints "[1, 2, 3, 4, 5, 10, 11, 12, 13, 14, 15]" ``` > Complexity: O(*m*), where *m* is the length of the right-hand-side > argument. --- 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)