iOS: Dismiss keyboard on click on view

ViewController-DismissKeyboard.swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action:
            #selector(ViewController.dismissKeyboard))
        view.addGestureRecognizer(tap)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // MARK: - Dismiss Keyboard
    
    func dismissKeyboard(){
        //Causes the view (or one of its embedded text fields) to resign the first responder status.
        view.endEditing(true)
    }

}

Using #selector will check your code at compile time to make sure the method you want to call actually exists. Even better, if the method doesn’t exist, you’ll get a compile error: Xcode will refuse to build your app, thus banishing to oblivion another possible source of bugs.
Source: https://swift.org/blog/swift-2-2-new-features/

Add
tap.cancelsTouchesInView = false
to prevent it affecting other GestureRecognizers