tap.swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let tapGestureRecognizer = UITapGestureRecognizer(
            target: self,
            action: #selector(ViewController.didTapView)
        )

        view.addGestureRecognizer(tapGestureRecognizer)
    }

    @objc func didTapView() {
        view.endEditing(true)
    }
}