Check out example codes for "swift dismiss keyboard on return". It will help you in understanding the concepts better.

Code Example 1

extension UIViewController: UITextFieldDelegate{
    public func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return true;
    }
}

override func viewDidLoad() {
    super.viewDidLoad()
    textField.delegate = self
}

Code Example 2

extension UIViewController: UITextFieldDelegate{
    public func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return true;
    }
}

override func viewDidLoad() {
    super.viewDidLoad()
    textField.delegate = self
}

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