HOW TO NAVIGATE FROM ONE VIEW CONTROLLER TO ANOTHER USING SWIFT IN IOS

let next = self.storyboard?.instantiateViewControllerWithIdentifier("DashboardController") as! DashboardController
self.presentViewController(next, animated: true, completion: nil)

let vc = self.storyboard?.instantiateViewControllerWithIdentifier("YourViewController") as! YourViewController
        let navigationController = UINavigationController(rootViewController: vc)
        self.presentViewController(navigationController, animated: true, completion: nil)

let secondViewController = self.storyboard?.instantiateViewController(withIdentifier: "Conversation_VC") as! Conversation_VC
self.navigationController?.pushViewController(secondViewController, animated: true)

var viewController: UIViewController? = storyboard().instantiateViewController(withIdentifier: "Identifier")
var navi = UINavigationController(rootViewController: viewController!)
navigationController?.pushViewController(navi, animated: true)

//To call or execute function after some time(After 5 sec)
DispatchQueue.main.asyncAfter(deadline: .now() + 5.0) {
    let next = self.storyboard?.instantiateViewController(withIdentifier: "AFVC") as! AddFileViewController
    self.present(next, animated: true, completion: nil) 
} 

let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let home = storyBoard.instantiateViewController(withIdentifier: "HOMEVC") as! HOMEVC
navigationController?.pushViewController(home, animated: true);

let secondviewController:UIViewController =  self.storyboard?.instantiateViewController(withIdentifier: "StoryboardIdOfsecondviewController") as? SecondViewController

self.navigationController?.pushViewController(secondviewController, animated: true)

let nextVC = self.storyboard?.instantiateViewController(withIdentifier: "NextViewController") as! NextViewController        
self.navigationController?.pushViewController(nextVC, animated: true)

let objViewController = self.storyboard?.instantiateViewController(withIdentifier: "ViewController") as! ViewController
self.navigationController?.pushViewController(objViewController, animated: true)

performSegue(withIdentifier: "idView", sender: self)

let vc = self.storyboard?.instantiateViewController(withIdentifier: "YourStoryboardID") as! swiftClassName

self.navigationController?.pushViewController(vc, animated: true)

var window: UIWindow?

fileprivate let navigationCtrl = UINavigationController()

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.
    self.createWindow()

    self.showLoginVC()

    return true
}

func createWindow() {
    let screenSize = UIScreen.main.bounds
    self.window = UIWindow(frame: screenSize)
    self.window?.backgroundColor = UIColor.white
    self.window?.makeKeyAndVisible()
    self.window?.rootViewController = navigationCtrl
}

func showLoginVC() {
    let storyboardBundle = Bundle.main
    // let storyboardBundle = Bundle(for: ClassName.self) // if you are not using main application, means may be you are crating a framework or library you can use this statement instead
    let storyboard = UIStoryboard(name: "LoginVC", bundle: storyboardBundle)
    let loginVC = storyboard.instantiateViewController(withIdentifier: "LoginVC") as! LoginVC
    navigationCtrl.pushViewController(loginVC, animated: false)
}

  let vc = MyViewController.instantiateFromMain()
  //here you can pass any data to the next view controller. for example we have a variable with name `myString` in our next view contoller and we want to pass the data my `self viewController`
  vc.myString = "This string passed by MyViewController"
  self.navigationController?.pushViewController(vc, animated: true)

let vc = UIStoryboard.init(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "YourViewController") as? YourViewController 
self.navigationController?.pushViewController(vc!, animated: true)

    let next = self.storyboard?.instantiateViewController(withIdentifier: "SecondViewController") as! SecondViewController

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