---
title: "receive(on:options:)"
framework: combine
role: symbol
role_heading: Instance Method
path: "combine/publisher/receive(on:options:)"
---

# receive(on:options:)

Specifies the scheduler on which to receive elements from the publisher.

## Declaration

```swift
func receive<S>(on scheduler: S, options: S.SchedulerOptions? = nil) -> Publishers.ReceiveOn<Self, S> where S : Scheduler
```

## Parameters

- `scheduler`: The scheduler the publisher uses for element delivery.
- `options`: Scheduler options used to customize element delivery.

## Mentioned in

Receiving and Handling Events with Combine Replacing Foundation Timers with Timer Publishers

## Return Value

Return Value A publisher that delivers elements using the specified scheduler.

## Discussion

Discussion You use the receive(on:options:) operator to receive results and completion on a specific scheduler, such as performing UI work on the main run loop. In contrast with subscribe(on:options:), which affects upstream messages, receive(on:options:) changes the execution context of downstream messages. In the following example, the subscribe(on:options:) operator causes jsonPublisher to receive requests on backgroundQueue, while the receive(on:options:) causes labelUpdater to receive elements and completion on RunLoop.main. let jsonPublisher = MyJSONLoaderPublisher() // Some publisher. let labelUpdater = MyLabelUpdateSubscriber() // Some subscriber that updates the UI.

jsonPublisher     .subscribe(on: backgroundQueue)     .receive(on: RunLoop.main)     .subscribe(labelUpdater) Prefer receive(on:options:) over explicit use of dispatch queues when performing work in subscribers. For example, instead of the following pattern: pub.sink {     DispatchQueue.main.async {         // Do something.     } } Use this pattern instead: pub.receive(on: DispatchQueue.main).sink {     // Do something. } note: receive(on:options:) doesn’t affect the scheduler used to call the subscriber’s receive(subscription:) method.

## See Also

### Specifying schedulers

- [subscribe(on:options:)](combine/publisher/subscribe(on:options:).md)