Passing Data between View Controllers without segue [duplicate]

Answer 1

One way is to use the navigational heiarchy to access the view controller.

From the viewController that you want to pass data it's tabBarController property should be the same instance of the tab bar that VC2 is a part of

func setStringForVC2(stringToSet:String) {
    guard let myTabBarController = tabBarController, let tabBarViewControllers = myTabBarController.viewControllers else {
        return
    }

    //need to access index 1 since vc's are stored in tabbarcontroller starting with 0, so 1 to access 2nd vc.
    if (tabBarViewControllers.indices.contains(1)) {
        if let vc2 = tabBarViewControllers[1] as? VC2Class {
            vc2.stringIWantToSet = stringToSet
        }
    }
}

Answer 2

If its a small data like some string or variable you can use UserDefault or pass data using that class variable like vc2.data = data How to use UserDefaults How to use UserDefaults in swift?

If its more like table or number of user list you can use plist store in your bundle at can retrieve from any view controller using Plist How do I get a plist as a Dictionary in Swift?

if two controller are some how connected you can use delegates. delegats:- Delegates in swift?

You can also use notifications if you are not sure when data will be available/ or send base on some action, or send if something is trigged.

Pass data using Notifications How to pass data using NotificationCentre in swift 3.0 and NSNotificationCenter in swift 2.0?

Answer 3

If you navigate programmatically to your second VC you can set Values like so (3rd line)

let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let newViewController = storyBoard.instantiateViewController(withIdentifier: "newViewController") as! NewViewController

newViewController.stringVariable = stringVariable

self.present(newViewController, animated: true, completion: nil)