json - Swift JSON 解析访问数组

Question

我正在从 Open - Elevation 中提取一个 JSON 文件但是，我无法从我提取的数据中访问数组的各个部分。我当前的 View Controller 中有 JSON 解析代码，它还允许我读取它自己的整个数组。

struct ElevationArray: Decodable {
    let results: [results]
}

struct results: Decodable {
    let latitude: Double
    let longitude: Double
    let elevation: Double

    init(json: [String: Any]){
      latitude = json["latitude"] as? Double ?? 0.0
      longitude = json["longitude"] as? Double ?? 0.0
      elevation = json["elevation"] as? Double ?? 0.0

    }
}

class FlightInfo: UITableViewController {


    @IBOutlet weak var Lat: UILabel!
    @IBOutlet weak var Long: UILabel!
    @IBOutlet weak var Elevation_label: UILabel!

    var elevationmain: Double?

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        Lat.text = "\(publocation.latitude)"
        Long.text = "\(publocation.longitude)"

        ElevationJSON()


    }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func ElevationJSON(){

        let jsonURLString = "https://api.open-elevation.com/api/v1/lookup?locations=41.161758,-8.583933"
        guard let url = URL(string: jsonURLString) else {return}

        URLSession.shared.dataTask(with: url) { (data, response, err) in
            //perhaps check err
            //also perhaps check response status 200 OK

            guard let data = data else { return }


            do {
                //let websiteDescription = try JSONDecoder().decode(WebsiteDescription.self, from: data)
               // print(websiteDescription.name, websiteDescription.description)

               let eleresults = try JSONDecoder().decode(ElevationArray.self, from: data)
               print(eleresults.results)

                let eletest = eleresults.results

                print(eletest)

                //self.elevationmain = Double(eleresults.results)
            } catch let jsonErr {
                print("Error serializing json:", jsonErr)
            }



            }.resume()
    }

}

这是我运行应用程序并打印出数组时得到的控制台输出。 enter image description here

Answer 1

eleresults.results(或 eletest)是一个 results 数组。

要访问所有数据，请使用循环:

for result in eletest {
    print(result.elevation)
}

如果您只想要第一个结果:

if let result = eletest.first {
    print(result.elevation)
}

顺便说一句 - 你的 results 结构应该重命名为有用的东西，比如 Elevation 或者比 results 更详细的描述(注意它应该开始带有大写字母。