# insert(contentsOf:at:) Inserts the elements of a sequence into the collection at the specified position. ``` mutating func insert(contentsOf newElements: C, at i: Self.Index) where C : Collection, Self.Element == C.Element ``` ## Parameters `newElements` The new elements to insert into the collection. `i` The position at which to insert the new elements. `index` must be a valid index of the collection. ## Discussion The new elements are inserted before the element currently at the specified index. If you pass the collection’s `endIndex` property as the `index` parameter, the new elements are appended to the collection. Here’s an example of inserting a range of integers into an array of the same type: ``` var numbers = [1, 2, 3, 4, 5] numbers.insert(contentsOf: 100...103, at: 3) print(numbers) // Prints "[1, 2, 3, 100, 101, 102, 103, 4, 5]" ``` Calling this method may invalidate any existing indices for use with this collection. > Complexity: O(*n* + *m*), where *n* is length of this collection and > *m* is the length of `newElements`. If `i == endIndex`, this method > is equivalent to `append(contentsOf:)`. --- 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)