Codable protocol has been added to Swift4.0 Foundation for native support for JSON parsing into Models.
At present there are ObjectMapper, SwiftyJSON, HandyJSON and other tripartite libraries to deal with the mutual transfer of Data and model, but with the native affirmation with the native implementation is better, reduce the dependence on the tripartite library, but also more stable.
Definition: public typeAlias Codable = Decodable & Encodable
Codable is a composite protocol made up of two protocols Decodable (decode for JSON to Model) and Encodable (encode for Model to JSON).