# map(_:) Creates a new column of typed values by applying the given thread-safe transform to every non-missing element of this untyped column. ``` func map(_ lazyTransform: @escaping (MLDataValue) -> T) -> MLDataColumn where T : MLDataValueConvertible ``` ## Parameters `lazyTransform` A thread-safe element transformation function. The implementation of the transform you provide should accept an `Element` of the column and return a transformed value of a type that conforms to [`MLDataValueConvertible`](/documentation/CreateML/MLDataValueConvertible). ## Return Value A new `MLDataColumn` typed to the return type of `lazyTransform`. --- 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)