---
title: "zip(_:_:_:)"
framework: combine
role: symbol
role_heading: Instance Method
path: "combine/publisher/zip(_:_:_:)-16rcy"
---

# zip(_:_:_:)

Combines elements from three other publishers and delivers groups of elements as tuples.

## Declaration

```swift
func zip<P, Q, R>(_ publisher1: P, _ publisher2: Q, _ publisher3: R) -> Publishers.Zip4<Self, P, Q, R> 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

Return Value A publisher that emits groups of elements from the upstream publishers as tuples.

## Discussion

Discussion Use zip(_:_:_:) 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 instances emit values; zip(_:_:_:) receives the oldest unconsumed value from each publisher and combines them into a tuple that it republishes to the downstream: let numbersPub = PassthroughSubject<Int, Never>() let lettersPub = PassthroughSubject<String, Never>() let emojiPub = PassthroughSubject<String, Never>() let fractionsPub  = PassthroughSubject<Double, Never>()

cancellable = numbersPub     .zip(lettersPub, emojiPub, fractionsPub)     .sink { print("\($0)") } numbersPub.send(1)         // numbersPub: 1       lettersPub:        emojiPub:       fractionsPub:         zip output: <none> numbersPub.send(2)         // numbersPub: 1,2     lettersPub:        emojiPub:       fractionsPub:         zip output: <none> numbersPub.send(3)         // numbersPub: 1,2,3   lettersPub:        emojiPub:       fractionsPub:         zip output: <none> fractionsPub.send(0.1)     // numbersPub: 1,2,3   lettersPub: "A"    emojiPub:       fractionsPub: 0.1     zip output: <none> lettersPub.send("A")       // numbersPub: 1,2,3   lettersPub: "A"    emojiPub:       fractionsPub: 0.1     zip output: <none> 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: <none> fractionsPub.send(0.8)     // numbersPub: 2,3     lettersPub: "B"    emojiPub:       fractionsPub: 0.8     zip output: <none> 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.

## See Also

### Collecting and republishing the oldest unconsumed elements from multiple publishers

- [zip(_:)](combine/publisher/zip(_:).md)
- [zip(_:_:)](combine/publisher/zip(_:_:)-4xn21.md)
- [zip(_:_:)](combine/publisher/zip(_:_:)-8d7k7.md)
- [zip(_:_:_:)](combine/publisher/zip(_:_:_:)-9yqi1.md)
- [zip(_:_:_:_:)](combine/publisher/zip(_:_:_:_:).md)