Home>

I was making a ToDo app to study, but when I wrote the code and started the simulator, the simulator fell down
I get an error with Thread 1: signal SIGABRT.

Error message

Thread 1: signal SIGABRT

### Corresponding source code
import UIKit
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {// Thread 1: signal SIGABRT
    var window: UIWindow?

    func application (_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?)->Bool {
        // Override point for customization after application launch.
        return true
    }
    func applicationWillResignActive (_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state.This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks.Games should use this method to pause the game.
    }
    func applicationDidEnterBackground (_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    }
    func applicationWillEnterForeground (_ application: UIApplication) {
        // Called as part of the transition from the background to the active state;here you can undo many of the changes made on entering the background.
    }
    func applicationDidBecomeActive (_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive.If the application was previously in the background, optionally refresh the user interface.
    }
    func applicationWillTerminate (_ application: UIApplication) {
        // Called when the application is about to terminate.Save data if appropriate.See also applicationDidEnterBackground :.
    }

}
Source code of the error-free part
import UIKit

var nakami = [String] ()
class TwoViewController: UIViewController {
    @IBOutlet var ToDoTextField: UITextField!
    @IBAction func ToDoAddButton (_ sender: Any) {
        // Put the characters entered in ToDoTextField into nakami
        nakami.append (ToDoTextField.text!)
        // save
        UserDefaults.standard.set (nakami, forKey: "ToDoList")

    }

    override func viewDidLoad () {super.viewDidLoad ()
        // Do any additional setup after loading the view.
    }
    override func didReceiveMemoryWarning () {
        super.didReceiveMemoryWarning ()
        // Dispose of any resources that can be recreated.
    }

    / *
    // MARK:-Navigation
    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare (for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    * /
}
import UIKit
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
    func tableView (_ tableView: UITableView, numberOfRowsInSection section: Int)->Int {
        return nakami.count
    }
    func tableView (_ tableView: UITableView, cellForRowAt indexPath: IndexPath)->UITableViewCell {
        let cell: UITableViewCell = tableView.dequeueReusableCell (withIdentifier: "cell", for: indexPath)
        cell.textLabel! .text = nakami [indexPath.row]
        return cell
    }

    override func viewDidLoad () {
        super.viewDidLoad ()


        if UserDefaults.standard.object (forKey: "ToDoList")! = nil {
            nakami = UserDefaults.standard.object (forKey: "ToDoList") as! [String]
        }

    }
    override func didReceiveMemoryWarning () {
        super.didReceiveMemoryWarning ()
        // Dispose of any resources that can be recreated.
    }

}
Tried

I searched and investigated various solutions, but I could not solve it.
Because I am a beginner, I wonder if there are any questions. I'm sorry. If there is any missing information, add it quickly.

Supplemental information (FW/tool version etc.)

Swift4.

  • Answer # 1

    Check the error log.
    This is due to the identifier ofUITableViewCell.

    In the above code

    let cell: UITableViewCell = tableView.dequeueReusableCell (withIdentifier: "cell", for: indexPath)

    withIdentifier is"cell". Please make sure that this identifier and Cell's Identifier on the Storyboard are the same. There is a field to enter the Identifier in the Attributes Inspector to check the Cell Identifier on the Storyboard. The Attributes Inspector is fourth from the left or third from the right in the button bar at the top of the column that appears to the right when you open the Storyboard. It looks like a down arrow.