I have two view controllers. One is navigated to with a "show" segue. There is a back button in the UINavigationBar that I have not changed. The back button goes back to the initial view controller. In the view controller with the back button, I am storing data in a variable.

How can I pass this data to my initial view controller?

I have tried:

```
viewWillDisappear(_ animated: Bool) {
    let vc = ViewController()
    vc.data = items
}

```

but the data in the initial view controller is empty when printed.

I've attempted to use:

```
prepare(for segue: ...)

```

but I'm not sure what segue the back button uses.

I can't seem to add an action of the back button to my view controller either.