# decode(type:decoder:) Decodes the output from the upstream using a specified decoder. ``` func decode(type: Item.Type, decoder: Coder) -> Publishers.Decode where Item : Decodable, Coder : TopLevelDecoder, Self.Output == Coder.Input ``` ## Parameters `type` The encoded data to decode into a struct that conforms to the protocol. `decoder` A decoder that implements the [`TopLevelDecoder`](/documentation/Combine/TopLevelDecoder) protocol. ## Return Value A publisher that decodes a given type using a specified decoder and publishes the result. ## Discussion Use [`decode(type:decoder:)`](/documentation/Combine/Publisher/decode(type:decoder:)) with a (or a for property lists) to decode data received from a or other data source using the protocol. In this example, a [`PassthroughSubject`](/documentation/Combine/PassthroughSubject) publishes a JSON string. The JSON decoder parses the string, converting its fields according to the protocol implemented by `Article`, and successfully populating a new `Article`. The [`Publishers.Decode`](/documentation/Combine/Publishers/Decode) publisher then publishes the `Article` to the downstream. If a decoding operation fails, which happens in the case of missing or malformed data in the source JSON string, the stream terminates and passes the error to the downstream subscriber. ``` struct Article: Codable { let title: String let author: String let pubDate: Date } let dataProvider = PassthroughSubject() cancellable = dataProvider .decode(type: Article.self, decoder: JSONDecoder()) .sink(receiveCompletion: { print ("Completion: \($0)")}, receiveValue: { print ("value: \($0)") }) dataProvider.send(Data("{\"pubDate\":1574273638.575666, \"title\" : \"My First Article\", \"author\" : \"Gita Kumar\" }".utf8)) // Prints: ".sink() data received Article(title: "My First Article", author: "Gita Kumar", pubDate: 2050-11-20 18:13:58 +0000)" ``` --- 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)