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

# flatMap(_:)

## Declaration

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

## See Also

### Transforming a String’s Characters

- [compactMap(_:)](swift/string/compactmap(_:).md)
- [flatMap(_:)](swift/string/flatmap(_:)-i3m9.md)
- [reduce(_:_:)](swift/string/reduce(_:_:).md)
- [reduce(into:_:)](swift/string/reduce(into:_:).md)
- [lazy](swift/string/lazy.md)