# subscribe(_:) Attaches the specified subscriber to this publisher. ``` func subscribe(_ subscriber: S) where S : Subscriber, Self.Failure == S.Failure, Self.Output == S.Input ``` ## Parameters `subscriber` The subscriber to attach to this publisher. After attaching, the subscriber can start to receive values. ## Discussion Always call this function instead of [`receive(subscriber:)`](/documentation/Combine/Publisher/receive(subscriber:)). Adopters of [`Publisher`](/documentation/Combine/Publisher) must implement [`receive(subscriber:)`](/documentation/Combine/Publisher/receive(subscriber:)). The implementation of [`subscribe(_:)`](/documentation/Combine/Publisher/subscribe(_:)-4u8kn) provided by [`Publisher`](/documentation/Combine/Publisher) calls through to [`receive(subscriber:)`](/documentation/Combine/Publisher/receive(subscriber:)). --- 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)