# nestedContainer(keyedBy:) Decodes a nested container keyed by the given type. ``` mutating func nestedContainer(keyedBy type: NestedKey.Type) throws -> KeyedDecodingContainer where NestedKey : CodingKey ``` ## Parameters `type` The key type to use for the container. ## Return Value A keyed decoding container view into `self`. ## Discussion> throws: `DecodingError.typeMismatch` if the encountered stored value is > not a keyed container. --- 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)