What does an unwind segue do?

Sources & Resources

Main Source: 🔗 Ace the iOS Interview

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TL/DR

You can use an unwind segue to jump to any UIViewController further up your UIViewController hierarchy while simultaneously destroying all other UIViewControllers in between. More specifically, you can use it to navigate back through one or more push, modal, or popover segues.

Let’s say you’re navigating from ViewControllerA → ViewControllerB → ViewControllerC and you want to go from ViewControllerC back to ViewControllerA.If you had to rely on just the back button alone, you’d have to go through ViewControllerB first.

With an unwind segue, we can jump directly to ViewControllerA and destroy ViewControllerB along the way.

In ViewControllerA, add:

@IBAction func unwindToViewControllerA(segue: UIStoryboardSegue) { }

You can leave the method body empty.

Then, in the UIViewController you’re departing from ViewControllerC you can drag from the body of the UIViewController to the Exit Icon and select the function we’ve created.

Now, when we press the “Go Directly to A” button, the application will navigate directly from ViewControllerC to ViewControllerA skipping over anddestroyingViewControllerB along the way.