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iOS

Posted by Matt Cantrill
Matt Cantrill
5,685 Points

xcode 6.1 error: trying to unwrap an optional but returns nil.

i am fairly new to swift but this is a problem that i can't find the answer to. every time i try to run my app to make a network call it pauses my app and complains that it found nil in an optional it was trying to unwrap.

here is my code:

import UIKit

class ViewController: UIViewController {

    private let apiKey = "ca73b3ab341efe41e970ae3f86270cc3"

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        let forecastBaseURL = NSURL(string: "https:api.forecast.io/forecast/\(apiKey)/")

        var forecastURL = NSURL(string: "-37.839337, 147.619493", relativeToURL: forecastBaseURL)


        let weatherData = NSData(contentsOfURL: forecastURL!)
        println(weatherData)
    }

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


}

1 Answer

Chris Shaw
Chris Shaw
26,676 Points

Hi Matt,

This error is a bit tricky because of the error returned, I got thrown by it when I first went through the course but after looking carefully noticed an space after the comma in the coordinates which was causing the error, simply remove that and the error will simply vanish as if nothing went wrong.

var forecastURL = NSURL(string: "-37.839337,147.619493", relativeToURL: forecastBaseURL)

Happy coding!

Matt Cantrill
Matt Cantrill
5,685 Points

Thank you so much. I never would have figured that out.