Error : Command failed due to signal : Segmentation fault: 11

Question

I am trying to get an array from dictionary, but I am getting an error for below line

self.items = self.dataDictionary["geoNames"] as NSArray

Complete code is as below

var dataDictionary: AnyObject!
var items: NSArray!

override func viewDidLoad() {
    super.viewDidLoad()

    var url = NSURL(string: "http://api.geonames.org/countryInfoJSON?username=temp")
    var urlRequest = NSURLRequest(URL: url!)

    NSURLConnection.sendAsynchronousRequest(urlRequest, queue:NSOperationQueue(), completionHandler:{ (response: NSURLResponse!, data: NSData!, error: NSError!) -> Void in

        if (data.length > 0 && error == nil){
            self.dataDictionary = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil)
            println(self.dataDictionary)
            self.items = self.dataDictionary["geoNames"] as NSArray
        }
    })
}

Answer 1

There are a few problems with your code:

1. Your code does not even compile. Segfault is coming from the compiler, not at runtime

2. You should cast the result from JSONObjectWithData as NSDictionary, not assign to a variable of type AnyObject!

3. Should use if to check if the casting works

4. The dictionary key is wrong. It is geonames (all lowercase)

Here is the functional code:

var url = NSURL(string: "http://api.geonames.org/countryInfoJSON?username=temp")
var urlRequest = NSURLRequest(URL: url!)

NSURLConnection.sendAsynchronousRequest(urlRequest, queue:NSOperationQueue(), completionHandler:{ (response: NSURLResponse!, data: NSData!, error: NSError!) -> Void in

    if (data.length > 0 && error == nil){
        if let jsonObject = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as? NSDictionary {

            let dataDictionary = jsonObject["geonames"]
            println(dataDictionary)

        }

    }
})