---
title: "flatMap(_:)"
framework: swift
role: symbol
role_heading: Instance Method
path: "swift/set/flatmap(_:)-6chuh"
---

# flatMap(_:)

## Declaration

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

## See Also

### Transforming a Set

- [compactMap(_:)](swift/set/compactmap(_:).md)
- [flatMap(_:)](swift/set/flatmap(_:)-i3my.md)
- [reduce(_:_:)](swift/set/reduce(_:_:).md)
- [reduce(into:_:)](swift/set/reduce(into:_:).md)
- [sorted()](swift/set/sorted().md)
- [sorted(by:)](swift/set/sorted(by:).md)
- [shuffled()](swift/set/shuffled().md)
- [shuffled(using:)](swift/set/shuffled(using:).md)
- [lazy](swift/set/lazy.md)