---
title: "init(_:)"
framework: swift
role: symbol
role_heading: Initializer
path: "swift/anyiterator/init(_:)-3m1u6"
---

# init(_:)

Creates an iterator that wraps a base iterator but whose type depends only on the base iterator’s element type.

## Declaration

```swift
init<I>(_ base: I) where Element == I.Element, I : IteratorProtocol
```

## Parameters

- `base`: An iterator to type-erase.

## Discussion

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<Int> 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<String> {     let lazyStrings = (0..<10).lazy.map { String($0) }     let iterator:         LazyMapSequence<Range<Int>, String>.Iterator         = lazyStrings.makeIterator()

return AnyIterator(iterator) }