# replaceSubrange(_:with:) Replaces the elements within the specified bounds with the given Unicode scalar values. ``` mutating func replaceSubrange(_ subrange: Range, with newElements: C) where C : Collection, C.Element == Unicode.Scalar ``` ## Parameters `subrange` The range of elements to replace. The bounds of the range must be valid indices of the view. `newElements` The new Unicode scalar values to add to the string. ## Discussion Calling this method invalidates any existing indices for use with this string. > Complexity: O(*m*), where *m* is the combined length of the view and > `newElements`. If the call to `replaceSubrange(_:with:)` simply > removes elements at the end of the string, the complexity is O(*n*), > where *n* is equal to `bounds.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)