CODEWITHSUNDEEP
swift
Omar Qureshi
Omar Qureshi

Reputation: 1319

Creating json swift app thing: fatal error: found nil when unwrapping json

I'm working on a json retrieving project or whatever, and I'm getting a fatal error while unwrapping a json. I think that the issue is that url is nil and I'm trying to unwrap it, but I'm not sure.

func getXRPData(urlString: String){
    let url = NSURL(string: urlString)

    let task = NSURLSession.sharedSession().dataTaskWithURL(url!) { (data, response, error) in
        dispatch_async(dispatch_get_main_queue(), {
            self.setLabels(data)
        })
    }

    task.resume()
}

func setLabels(xrpDataL: NSData){
    var jsonError: NSError?
    var percent = "%"
    var dollarSIGN = "$"

    let json = NSJSONSerialization.JSONObjectWithData(xrpDataL, options: nil, error: &jsonError) as! NSDictionary
    //supply of xrp
    if let supply = json["supply"] as? String{


        var numberFormatter = NSNumberFormatter()
        numberFormatter.numberStyle = NSNumberFormatterStyle.DecimalStyle
        if let result = numberFormatter.numberFromString(supply){
            var finalResult = numberFormatter.stringFromNumber(result)
            totalXRP.text = finalResult

        }

    }

Upvotes: 0

Views: 67

Answers (1)

Patrick Lynch
Patrick Lynch

Reputation: 2782

Instead of force unwrapping, you should unwrap the results of JSONObjectWithData with an optional binding (if let) and a conditional downcast (as?):

if let json = NSJSONSerialization.JSONObjectWithData(xrpDataL, options: nil, error: &jsonError) as? NSDictionary {
    // Continue parsing
} else {
    // Handle error
}

Upvotes: 1

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