# filter(_:) Creates an asynchronous sequence that contains, in order, the elements of the base sequence that satisfy the given predicate. ``` @preconcurrency func filter(_ isIncluded: @escaping @Sendable (Self.Element) async -> Bool) -> AsyncFilterSequence ``` ## Parameters `isIncluded` A closure that takes an element of the asynchronous sequence as its argument and returns a Boolean value that indicates whether to include the element in the filtered sequence. ## Return Value An asynchronous sequence that contains, in order, the elements of the base sequence that satisfy the given predicate. ## Discussion In this example, an asynchronous sequence called `Counter` produces `Int` values from `1` to `10`. The `filter(_:)` method returns `true` for even values and `false` for odd values, thereby filtering out the odd values: ``` let stream = Counter(howHigh: 10) .filter { $0 % 2 == 0 } for await number in stream { print(number, terminator: " ") } // Prints "2 4 6 8 10 " ``` --- 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)