# transformingAttributes(_:_:_:) Returns an attributed string by calling a closure that transforms two attributes of a source attributed string. ``` @preconcurrency func transformingAttributes(_ k: K1.Type, _ k2: K2.Type, _ c: (inout AttributedString.SingleAttributeTransformer, inout AttributedString.SingleAttributeTransformer) -> Void) -> AttributedString where K1 : AttributedStringKey, K2 : AttributedStringKey, K1.Value : Sendable, K2.Value : Sendable ``` ## Parameters `k` The [`AttributedStringKey`](/documentation/Foundation/AttributedStringKey) that identifies an attribute to transform. `k2` The [`AttributedStringKey`](/documentation/Foundation/AttributedStringKey) that identifies a second attribute to transform. `c` A closure that receives two [`AttributedString.SingleAttributeTransformer`](/documentation/Foundation/AttributedString/SingleAttributeTransformer) instances that you use to access and alter the attributes’ ranges and values. ## Return Value An attributed string with the applied transformations to the specified attributes. --- 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)