Appending data to TableView cell Fatal Error on nil while unwrapping an Optional value

Question

Months ago I wrote this app that retrieves data from Firebase and show them in TableViewCell. Opening the project today I'm facing this

fatal error: unexpectedly found nil while unwrapping an Optional value

Actually I don't know what to do.

The lines of code that generates the problem are the follow:

if snapshot.exists()
{
 self.acceptedQuests.append(InfoQuest(rest.key, quest?["name"] as! String, quest?["description"] as! String, quest?["image"] as! String))
 print(self.acceptedQuests.count)
 self.tableView!.reloadData()
}

Any help will be really appreciated.

score 0 · Accepted Answer · answered Jun 25 '17 at 19:57

Your error is either occurring when you are casting the quest elements, or when referencing the table view. I would be surprised if your table view was nil so it was probably happening when you are casting. This is an example where a guard statement would work really well

if snapshot.exists()
{
   guard let name = quest?["name"] as? String,
         let description = quest?["description"] as? String,
         let image = quest?["image"] as? String,
         let tableView = self.tableView else
         {
            // One of those values was either nil or could not become a String
           return
         }
   self.acceptedQuests.append(InfoQuest(rest.key, name, description, image))
   print(self.acceptedQuests.count)
   tableView.reloadData()
}

This will stop you from accessing a nil item. If any of the casts fail or any value is nil the else block will execute and return

Thanks, now the table don't crash but still not retrieve data and append them... — rulezzer, Jun 25 '17 at 20:40
Add a print statement inside the guard block, there you can see what values are nil via print(quest?["name"]) — Garrigan Stafford, Jun 25 '17 at 21:04

Appending data to TableView cell Fatal Error on nil while unwrapping an Optional value

1 Answers1