# init(_:) Creates an iterator that wraps a base iterator but whose type depends only on the base iterator’s element type. ``` init(_ base: I) where Element == I.Element, I : IteratorProtocol ``` ## Parameters `base` An iterator to type-erase. ## Discussion You can use `AnyIterator` to hide the type signature of a more complex iterator. For example, the `digits()` function in the following example creates an iterator over a collection that lazily maps the elements of a `Range` instance to strings. Instead of returning an iterator with a type that encapsulates the implementation of the collection, the `digits()` function first wraps the iterator in an `AnyIterator` instance. ``` func digits() -> AnyIterator { let lazyStrings = (0..<10).lazy.map { String($0) } let iterator: LazyMapSequence, String>.Iterator = lazyStrings.makeIterator() return AnyIterator(iterator) } ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)