# zip(_:_:_:) Combines elements from three other publishers and delivers groups of elements as tuples. ``` func zip(_ publisher1: P, _ publisher2: Q, _ publisher3: R) -> Publishers.Zip4 where P : Publisher, Q : Publisher, R : Publisher, Self.Failure == P.Failure, P.Failure == Q.Failure, Q.Failure == R.Failure ``` ## Parameters `publisher1` A second publisher. `publisher2` A third publisher. `publisher3` A fourth publisher. ## Return Value A publisher that emits groups of elements from the upstream publishers as tuples. ## Discussion Use [`zip(_:_:_:)`](/documentation/Combine/Publisher/zip(_:_:_:)-16rcy) to return a new publisher that combines the elements from three other publishers to publish a tuple to the downstream subscriber. The returned publisher waits until all four publishers have emitted an event, then delivers the oldest unconsumed event from each publisher as a tuple to the subscriber. In this example, several [`PassthroughSubject`](/documentation/Combine/PassthroughSubject) instances emit values; [`zip(_:_:_:)`](/documentation/Combine/Publisher/zip(_:_:_:)-16rcy) receives the oldest unconsumed value from each publisher and combines them into a tuple that it republishes to the downstream: ``` let numbersPub = PassthroughSubject() let lettersPub = PassthroughSubject() let emojiPub = PassthroughSubject() let fractionsPub = PassthroughSubject() cancellable = numbersPub .zip(lettersPub, emojiPub, fractionsPub) .sink { print("\($0)") } numbersPub.send(1) // numbersPub: 1 lettersPub: emojiPub: fractionsPub: zip output: numbersPub.send(2) // numbersPub: 1,2 lettersPub: emojiPub: fractionsPub: zip output: numbersPub.send(3) // numbersPub: 1,2,3 lettersPub: emojiPub: fractionsPub: zip output: fractionsPub.send(0.1) // numbersPub: 1,2,3 lettersPub: "A" emojiPub: fractionsPub: 0.1 zip output: lettersPub.send("A") // numbersPub: 1,2,3 lettersPub: "A" emojiPub: fractionsPub: 0.1 zip output: emojiPub.send("😀") // numbersPub: 2,3 lettersPub: "A" emojiPub: "😀" fractionsPub: 0.1 zip output: (1, "A", "😀", 0.1) lettersPub.send("B") // numbersPub: 2,3 lettersPub: "B" emojiPub: fractionsPub: zip output: fractionsPub.send(0.8) // numbersPub: 2,3 lettersPub: "B" emojiPub: fractionsPub: 0.8 zip output: emojiPub.send("🥰") // numbersPub: 3 lettersPub: "B" emojiPub: fractionsPub: 0.8 zip output: (2, "B", "🥰", 0.8) // Prints: // (1, "A", "😀", 0.1) // (2, "B", "🥰", 0.8) ``` If any upstream publisher finishes successfully or fails with an error, so too does the zipped publisher. --- 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)