fatal error: unexpectedly found nil while unwrapping an Optional value - why?

Question

I'm pretty new to coding in Swift and I'm not too sure what's happening here - can anyone help?

Thanks

import UIKit

class SecondViewController: UIViewController {

    var toDoItems:[String] = []


    @IBOutlet weak var toDoItem: UITextField!

    @IBAction func addItem(sender: AnyObject) {

        toDoItems.append(toDoItem.text)
fatal error: unexpectedly found nil while unwrapping an Optional value
(lldb) 

        println(toDoItems)



    }
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

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


}

Rob Rob · Accepted Answer · 2014-10-13T21:44:06

Most likely, your IBOutlet, toDoItem, was not bound successfully to a UITextField in Interface Builder. Check the outlets for your text field in Interface Builder and make sure it's hooked up successfully.

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If the outlet is hooked up properly, another candidate source of this problem is the instantiation of the view controller itself. If you instantiated it programmatically (e.g. SecondViewController() instead of storyboard.instantiateViewControllerWithIdentifier(...)), that would also result in this error.

fatal error: unexpectedly found nil while unwrapping an Optional value - why?

1 Answers