# map(_:) Returns a new result, mapping any success value using the given transformation. ``` func map(_ transform: (Success) -> NewSuccess) -> Result where NewSuccess : ~Copyable ``` ## Parameters `transform` A closure that takes the success value of this instance. ## Return Value A `Result` instance with the result of evaluating `transform` as the new success value if this instance represents a success. ## Discussion Use this method when you need to transform the value of a `Result` instance when it represents a success. The following example transforms the integer success value of a result into a string: ``` func getNextInteger() -> Result { /* ... */ } let integerResult = getNextInteger() // integerResult == .success(5) let stringResult = integerResult.map { String($0) } // stringResult == .success("5") ``` --- 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)