ios - Passing values from one view controller to another in Swift

Question

I am working on Swift, I've got an error in tableview's didSelectRowAtIndexPath method. I want to pass a value to another view controller i.e 'secondViewController'. Here EmployeesId is an Array. The relevant code is as follows:

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    var view: Dashboard = self.storyboard?.instantiateViewControllerWithIdentifier("Dashboard") as Dashboard

    self.navigationController?.pushViewController(view, animated: true)
    secondViewController.UserId = employeesId[indexPath.item]  //getting an error here.
}

But I am getting this Error: fatal error: unexpectedly found nil while unwrapping an Optional value.

Any help will be appreciated.

Answer 1

Here's a general solution with two assumptions. First, UserId is not a UILabel. Second, you meant to use view which was instantiated in the second line, instead of using secondViewController

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    var view: Dashboard = self.storyboard?.instantiateViewControllerWithIdentifier("Dashboard") as Dashboard
    view.userId = employeesId[indexPath.row]
    self.navigationController?.pushViewController(view, animated: true)
    
}

Here's what Dashboard looks like:

class Dashboard: UIViewController {
    var userId: String!
    @IBOutlet var userIDLabel: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        userIDLabel.text = UserId
    }

    ...
}