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iOS

Posted by Frank Ogwaro
Frank Ogwaro
Courses Plus Student 7,941 Points

Vale of optional type 'NSURL?' not unwrapped; did you mean to use '!' or '?'?

Here is my code I'm currently on Xcode 6.1 Yosemite and I'm have trouble understanding why I'm getting this error every time I try to run the app.

let baseURL = NSURL(string: "https://api.forecast.io/forecast/\(apiKey)/")
        let forecastURL = NSURL(string: "37.8267,-122.423", relativeToURL: baseURL)

        let sharedSession = NSURLSession.sharedSession()
        let downloadTask: NSURLSessionDownloadTask = sharedSession.downloadTaskWithURL(forecastURL, completionHandler: { (location: <NSURL!>, response: <NSURLResponse!>, error: <NSError!>) -> Void in
            println(response)
        })

    }

4 Answers

Chris Shaw
Chris Shaw
26,676 Points

Hi Frank,

This was an change that was made to Xcode 6.1, what it's asking you to do is add a bang or exclamation mark after forecastUrl on the line where you've declared downloadTask.

For example.

let downloadTask: NSURLSessionDownloadTask = sharedSession.downloadTaskWithURL(forecastURL!, completionHandler: { (location: NSURL!, response: NSURLResponse!, error: NSError!) -> Void in
    println(response)
})
Frank Ogwaro
PLUS
Frank Ogwaro
Courses Plus Student 7,941 Points
Frank Ogwaro
Frank Ogwaro
Courses Plus Student 7,941 Points

Hi guys I'm reviewing this course. I've gone and added the bang to forecastURL

let downloadTask: NSURLSessionDownloadTask = sharedSession.downloadTaskWithURL(forecastURL!, completionHandler: { (location: NSURL!, response: NSURLResponse!, error: NSError!) -> Void in
            println(response)

when I do so I get Expected perimeter type following ':' error when running the app.

Chris Shaw
Chris Shaw
26,676 Points

Hi Frank,

Could you please post the rest of your code minus your API key.

Cheers.

Frank Ogwaro
PLUS
Frank Ogwaro
Courses Plus Student 7,941 Points
Frank Ogwaro
Frank Ogwaro
Courses Plus Student 7,941 Points

Here it is.

 let baseURL = NSURL(string: "https://api.forecast.io/forecast/\(apiKey)/")

        let forecastURL = NSURL(string: "37.8267,-122.423", relativeToURL: baseURL)

        let sharedSession = NSURLSession.sharedSession()
        let downloadTask: NSURLSessionDownloadTask = sharedSession.downloadTaskWithURL(forecastURL!, completionHandler: { (location: NSURL!, response: NSURLResponse!, error: NSError!) -> Void in
            println(response)
        })
        downloadTask.resume()


    }
Frank Ogwaro
PLUS
Frank Ogwaro
Courses Plus Student 7,941 Points
Frank Ogwaro
Frank Ogwaro
Courses Plus Student 7,941 Points

I ended up figuring it out from this thread Please help with coding error/issue. Elijah Gartin's answer fixed my issue. Did not realize that I had to get rid of the blue boxes.