How to hide keyboard in swift on pressing return key?

import UIKit

class ViewController: UIViewController, UITextFieldDelegate {

    @IBOutlet var myTextField : UITextField

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        self.myTextField.delegate = self;
    }


 func textFieldShouldClear(_ textField: UITextField) -> Bool // called when 'return' key pressed. return false to ignore.

    {

        textField.resignFirstResponder()

        return true

    }
}