# sink(receiveCompletion:receiveValue:) Attaches a subscriber with closure-based behavior. ``` func sink(receiveCompletion: @escaping (Subscribers.Completion) -> Void, receiveValue: @escaping (Self.Output) -> Void) -> AnyCancellable ``` ## Parameters `receiveValue` The closure to execute on receipt of a value. ## Return Value A cancellable instance, which you use when you end assignment of the received value. Deallocation of the result will tear down the subscription stream. ## Discussion Use [`sink(receiveCompletion:receiveValue:)`](/documentation/Combine/Publisher/sink(receiveCompletion:receiveValue:)) to observe values received by the publisher and process them using a closure you specify. In this example, a publisher publishes integers to a [`sink(receiveCompletion:receiveValue:)`](/documentation/Combine/Publisher/sink(receiveCompletion:receiveValue:)) operator’s `receiveValue` closure that prints them to the console. Upon completion the [`sink(receiveCompletion:receiveValue:)`](/documentation/Combine/Publisher/sink(receiveCompletion:receiveValue:)) operator’s `receiveCompletion` closure indicates the successful termination of the stream. ``` let myRange = (0...3) cancellable = myRange.publisher .sink(receiveCompletion: { print ("completion: \($0)") }, receiveValue: { print ("value: \($0)") }) // Prints: // value: 0 // value: 1 // value: 2 // value: 3 // completion: finished ``` This method creates the subscriber and immediately requests an unlimited number of values, prior to returning the subscriber. The return value should be held, otherwise the stream will be canceled. --- 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)