---
title: "map(_:)"
framework: swift
role: symbol
role_heading: Instance Method
path: "swift/lazysequenceprotocol/map(_:)"
---

# map(_:)

Returns a LazyMapSequence over this Sequence.  The elements of the result are computed lazily, each time they are read, by calling transform function on a base element.

## Declaration

```swift
func map<U>(_ transform: @escaping (Self.Element) -> U) -> LazyMapSequence<Self.Elements, U>
```