Swift 2.0 fatal error: unexpectedly found nil while unwrapping an Optional value (lldb)

let imgURL:NSURL = NSURL(string: "\(ImageName)")!

at the above line,i'm getting fatal error

fatal error: unexpectedly found nil while unwrapping an Optional value (lldb)

Code :

let ImageName = obj["image"] as! String

 let imgURL:NSURL = NSURL(string: "\(ImageName)")!
 let request: NSURLRequest = NSURLRequest(URL: imgURL)

  let session = NSURLSession.sharedSession()

  let Imgtask = session.dataTaskWithRequest(request){
                            (data, response, error) -> Void in

   if (error == nil && data != nil)
    {
       func display_image()
       {
           pointAnnoation.DisplayImage = UIImage(data: data!)
        }
        dispatch_async(dispatch_get_main_queue(), display_image)
     }

   }

   Imgtask.resume()

From the above code im trying to store my image from database in annotation

if i printed the 'ImageName' it returns the name from the database correctly, but unable to retain the image

it resulting in the error while running.

Try to use guard or if let for helping yourself.

let ImageName = obj["image"] as! String

 if let imgURL = NSURL(string: ImageName) {
     let request: NSURLRequest = NSURLRequest(URL: imgURL)

     let session = NSURLSession.sharedSession()

     let Imgtask = session.dataTaskWithRequest(request){ (data, response, error) -> Void in

        if (error == nil && data != nil)
        {
            // What's that func??
            func display_image()
            {
                pointAnnoation.DisplayImage = UIImage(data: data!)
            }
            dispatch_async(dispatch_get_main_queue(), display_image)
         }

       }
 }
 Imgtask.resume()