How I can transfer data between controllers when returning to the last screen? Swift

Question

In the application, I am asked to select a category, when I click, I move to the next screen from the tableView, and when I click on the desired category, it should be saved and return to the previous controller, where instead of "select a category" my chosen category will be.

I using by this method navigationController?.popViewController(animated: true), which brings me back to the last screen. As I understand it, prepare is not called, but since I know exactly where I'm going, I can, in the method from which I call pop ..., get access to the controller I am switching to and pass it the necessary properties? But how?

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
  let currentCell = categories[indexPath.row]
    /?
    /?
  navigationController?.popViewController(animated: true)
}

Answer 1

When you go to the select screen do

let vc = ///
vc.delegate = self
// push

then inside didASelectRowAt

class CategoryViewController:UIViewController {
 weak var delegate:PreviousVC?
 ////
}

delegate?.sendData(someData)
navigationController?.popViewController(animated: true)

---

Another option inside didASelectRowAt to

// access previous vc
let previousVC = self.navigationController!.viewControllers[self.navigationController!.viewControllers.count - 2] as! PreviousVc
previousVC.sendData(someData)
// pop here

---

Edit: inside the firstVC

     override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if let secondVC = segue.destination as? SecondViewController {
          secondVC.delegate = self   
        }
    }