Opening a navigation controller from Tabbar with back button on first ViewController - ios

Question

I know this question has been asked so many times on the SO, but I am asking this just because it is relevantly different and also some answers are out dated and some are in Objective-c which I can not understand properly.
USE CASE:
I have a UITabBar controller, and it is working fine. Let say I have 4 tabs in it and user click on the button given in the Tab 4. now on it I have to open some series of View Controllers. let say User has following patteren to follow.
4.A-->4.B--> 4.C and can go back to first like so: 4.C-->4.B-->4.A
And finally User must also be allowed to go back to Tab4 after closing 4.A view controller
WHAT I DID:
I am able to open the View controller using this code.
let VC1 = storyboard.instantiateViewController(withIdentifier :"myVcId") as! UIViewController
let navController = UINavigationController(rootViewController: VC1) // Creating a navigation controller with VC1 at the root of the navigation stack.
self.present(navController, animated:true, completion: nil)
This is opening a navigation controller and having me navigate the view controller as per my requirements but I want following thing too
WHAT I WANT: As I am presenting the Navigation Controller modally, I want to show the back button at very first view controller, and I want that if user select back button it kills all the Navigation controller and go the previous view controller where he came from

Answer 1

You need to select the 4th tab and embed it inside a navigation then do
let vc = storyboard.instantiateViewController(withIdentifier :"myVcId") as! UIViewController
self.navigationController?.pushViewController(vc, animated: true)
then you'll see a back on that first vc , to return to that tab do
self.navigationController?.popToRootViewController(animated: true)

Answer 2

As far as I understood, your structure looks like this:
A TabBarController, with ViewControllers as tabs, and from them you present a navigation controller with other ViewControllers, like this:
(TabBar) -vc-> (View) -present-> (NavController) -root-vc-> (View)
I have two suggestions for making it easier to handle.
First option
Use navigation controllers as tabs for your TabBarController, and make your ViewControllers that are tabs their root view controllers.
(TabBar) -vc-> (NavController) -root-vc-> (View) -push-> (View)
Second option
Another option is to use a navigation controller as your initial view controller, and make your tab bar this navigation controller's root view controller.
(NavController) -root-vc-> (TabBar) -view-> (View) -push-> (View)
Both options should work, and the first one should be a little easier to handle.

Answer 3

You need to instantiate the navigationController with 4A as the rootViewController.
Then, in the viewDidLoad for 4A, you need to instantiate 4B, and push it to your navigationController.
Then, finally, in your 4B viewController's viewDidLoad you need to instantiate 4C and push it to your navigationController's stack.
P.S.: Push all the viewControllers without animations.
This should be achieving your strange scenario.
EDITED:
You need your 4th tab from your tabBar to be a navigationController,
and its root view Controller to be the initial VC which will then push
your new navController, otherwise you won't have the back button.
So, your stack should be something like this:
4CVC
|-(push)
4BVC
|-(push)
4AVC
|-(push)
newNavController
|-(push)
someVC
|
navController
|
tab1 tab2 tab3 tab4
|
tabBar