---
title: "flatMap(_:)"
framework: swift
role: symbol
role_heading: Instance Method
path: "swift/sequence/flatmap(_:)-383uq"
---

# flatMap(_:)

## Declaration

```swift
func flatMap<ElementOfResult>(_ transform: (Self.Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult]
```

## See Also

### Transforming a Sequence

- [map(_:)](swift/sequence/map(_:).md)
- [compactMap(_:)](swift/sequence/compactmap(_:).md)
- [flatMap(_:)](swift/sequence/flatmap(_:)-jo2y.md)
- [reduce(_:_:)](swift/sequence/reduce(_:_:).md)
- [reduce(into:_:)](swift/sequence/reduce(into:_:).md)
- [lazy](swift/sequence/lazy.md)