---
title: Publishers.Concatenate
framework: combine
role: symbol
role_heading: Structure
path: combine/publishers/concatenate
---

# Publishers.Concatenate

A publisher that emits all of one publisher’s elements before those from another publisher.

## Declaration

```swift
struct Concatenate<Prefix, Suffix> where Prefix : Publisher, Suffix : Publisher, Prefix.Failure == Suffix.Failure, Prefix.Output == Suffix.Output
```

## Topics

### Creating a concatenate publisher

- [init(prefix:suffix:)](combine/publishers/concatenate/init(prefix:suffix:).md)

### Declaring supporting types

- [Publishers.Concatenate.Output](combine/publishers/concatenate/output.md)
- [Publishers.Concatenate.Failure](combine/publishers/concatenate/failure.md)

### Inspecting publisher properties

- [prefix](combine/publishers/concatenate/prefix.md)
- [suffix](combine/publishers/concatenate/suffix.md)

### Comparing publishers

- [==(_:_:)](combine/publishers/concatenate/==(_:_:).md)

### Default Implementations

- [Equatable Implementations](combine/publishers/concatenate/equatable-implementations.md)

## Relationships

### Conforms To

- [Equatable](swift/equatable.md)
- [Publisher](combine/publisher.md)

## See Also

### Applying sequence operations to elements

- [Publishers.DropUntilOutput](combine/publishers/dropuntiloutput.md)
- [Publishers.Drop](combine/publishers/drop.md)
- [Publishers.DropWhile](combine/publishers/dropwhile.md)
- [Publishers.TryDropWhile](combine/publishers/trydropwhile.md)
- [Publishers.PrefixWhile](combine/publishers/prefixwhile.md)
- [Publishers.TryPrefixWhile](combine/publishers/tryprefixwhile.md)
- [Publishers.PrefixUntilOutput](combine/publishers/prefixuntiloutput.md)