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

# zip(_:)

Combines elements from another publisher and deliver pairs of elements as tuples.

## Declaration

```swift
func zip<P>(_ other: P) -> Publishers.Zip<Self, P> where P : Publisher, Self.Failure == P.Failure
```

## Parameters

- `other`: Another publisher.

## Return Value

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

## Discussion

Discussion Use zip(_:) to combine the latest elements from two publishers and emit a tuple to the downstream. The returned publisher waits until both publishers have emitted an event, then delivers the oldest unconsumed event from each publisher together as a tuple to the subscriber. Much like a zipper or zip fastener on a piece of clothing pulls together rows of teeth to link the two sides, zip(_:) combines streams from two different publishers by linking pairs of elements from each side. In this example, numbers and letters are PassthroughSubjects that emit values; once zip(_:) receives one value from each, it publishes the pair as a tuple to the downstream subscriber. It then waits for the next pair of values.  let numbersPub = PassthroughSubject<Int, Never>()  let lettersPub = PassthroughSubject<String, Never>()

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

// Prints:  //  (1, "A")  //  (2, "B") If either upstream publisher finishes successfully or fails with an error, the zipped publisher does the same.

## See Also

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

- [zip(_:_:)](combine/publisher/zip(_:_:)-4xn21.md)
- [zip(_:_:)](combine/publisher/zip(_:_:)-8d7k7.md)
- [zip(_:_:_:)](combine/publisher/zip(_:_:_:)-9yqi1.md)
- [zip(_:_:_:)](combine/publisher/zip(_:_:_:)-16rcy.md)
- [zip(_:_:_:_:)](combine/publisher/zip(_:_:_:_:).md)