jsondecoder

问题 This question already has answers here : how to unwrap swift optionals within a struct (1 answer) What does “Fatal error: Unexpectedly found nil while unwrapping an Optional value” mean? (11 answers) Closed 8 months ago . as an old C programmer I am trying to get into Swift. I have already overcome many hurdles but for the following I am out of ideas. I am building a little home schooling app and want to store/retrieve the high scores to/from a JSON file. import Foundation struct HighScores:

问题 Is there a JSON DOM that can read any JSON, regardless of type, and store it into something like a Dictionary hierarchy? Consider this JSON and code... var jsonData = """ { "type":"ListWrapper", "objectData": { "label":"SuperItems", "items":[ { "value":"First" }, { "value":"Second" }, { "value":"Third" }, { "value":"Fourth" } ] } } """.data(using:.utf8)! Here's the first part of what we're trying to do. (Note: This doesn't actually work.) class TestObject : Codable { var name:String? var

问题 I have the following JSON data I get from an API: {"datatable": {"data" : [ ["John", "Doe", "1990-01-01", "Chicago"], ["Jane", "Doe", "2000-01-01", "San Diego"] ], "columns": [ { "name": "First", "type": "String" }, { "name": "Last", "type": "String" }, { "name": "Birthday", "type": "Date" }, { "name": "City", "type": "String" } ]} } A later query could result the following: {"datatable": {"data" : [ ["Chicago", "Doe", "John", "1990-01-01"], ["San Diego", "Doe", "Jane", "2000-01-01"] ],

问题 Here is my problem, when I receive some JSON, it happens that some values do not match the required type. I don't really mind, I'm only interested by the value when its type is correct. For instance, the following structure: struct Foo : Decodable { var bar : Int? } I'd like it to match these JSON: { "bar" : 42 } => foo.bar == 42 { "bar" : null } => foo.bar == nil { "bar" : "baz" } => foo.bar == nil Indeed I'm looking for an optional Int , so whenever it's an integer I want it, but when it's

来源： https://stackoverflow.com/questions/64311232/decoding-json-array-with-codable-swift-5

来源： https://stackoverflow.com/questions/64311232/decoding-json-array-with-codable-swift-5

问题 I've noticed that while Quicktype.io does a very good job of parsing JSON into SWIFt, occasionally it resorts to a lot of auxiliary functions and methods. For the following, it generated about 15 additional methods. Some of these are familiar such as NSNull, however, two are unfamiliar to me such as JSONAny and it seems like there ought to be a way around them. The JSONAny class for example, has about 12 functions in it and it is used to parse just one field that is not that important to me.

问题 In playgrounds, the following code produces an error: import Foundation struct Model: Codable { let textBody: String enum CodingKeys: String, CodingKey { case textBody = "TextBody" } } let json = """ { "TextBody": "First Line\n\nLastLine" } """.data(using: .utf8)! let model = try! JSONDecoder().decode(Model.self, from: json) Fatal error: 'try!' expression unexpectedly raised an error: Swift.DecodingError.dataCorrupted(Swift.DecodingError.Context(codingPath: [], debugDescription: "The given

问题 if I want to decode my JSON there is something weird happening. Here's the structs struct chatMessages : Codable { var message: [chatMessage] } struct chatMessage : Codable { var user: String var message: String var status: String var latitude: Double var longitude: Double init(from decoder: Decoder) throws { let values = try decoder.container(keyedBy: CodingKeys.self) user = try values.decode(String.self, forKey: .user) message = try values.decode(String.self, forKey: .message) status = try

问题 if I want to decode my JSON there is something weird happening. Here's the structs struct chatMessages : Codable { var message: [chatMessage] } struct chatMessage : Codable { var user: String var message: String var status: String var latitude: Double var longitude: Double init(from decoder: Decoder) throws { let values = try decoder.container(keyedBy: CodingKeys.self) user = try values.decode(String.self, forKey: .user) message = try values.decode(String.self, forKey: .message) status = try