# replaceValue(at:inPropertyWithKey:withValue:) Replaces the object at the specified index in the collection specified by the passed key. ``` func replaceValue(at index: Int, inPropertyWithKey key: String, withValue value: Any) ``` ## Discussion The method `replaceIn:atIndex:` is invoked if it exists. If no corresponding scripting-KVC-compliant method (`-replaceInatIndex:`) is found, this method invokes `-mutableArrayValueForKey:` and mutates the result. > Note: > Prior to OS X version 10.4, this method did not invoke `-mutableArrayValueForKey:`. --- 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)