Correctly Parsing JSON in Swift 3

Question

I\'m trying to fetch a JSON response and store the results in a variable. I\'ve had versions of this code work in previous releases of Swift, until the GM version of Xcode 8

Answer 1

The problem is with the API interaction method. The JSON parsing is changed only in syntax. The main problem is with the way of fetching data. What you are using is a synchronous way of getting data. This doesn't work in every case. What you should be using is an asynchronous way to fetch data. In this way, you have to request data through the API and wait for it to respond with data. You can achieve this with URL session and third party libraries like Alamofire. Below is the code for URL Session method.

let urlString = "https://api.forecast.io/forecast/apiKey/37.5673776,122.048951"
let url = URL.init(string: urlString)
URLSession.shared.dataTask(with:url!) { (data, response, error) in
    guard error == nil else {
        print(error)
    }
    do {
        let Data = try JSONSerialization.jsonObject(with: data!) as! [String:Any]
        // Note if your data is coming in Array you should be using [Any]()
        //Now your data is parsed in Data variable and you can use it normally
        let currentConditions = Data["currently"] as! [String:Any]
        print(currentConditions)
        let currentTemperatureF = currentConditions["temperature"] as! Double
        print(currentTemperatureF)
    } catch let error as NSError {
        print(error)
    }
}.resume()