Sort array String in Swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        let persons = ["ab", "bb", "ab", "ba", "aa"]
        let sortedPersons = persons.sorted { (s1: String, s2: String) -> Bool in
            return s1 < s2
        }
        let sortedPersons2 = persons.sorted(by: mySorted)
        print("persons", persons)
        print("sortedPersons", sortedPersons)
        print("sortedPersons2", sortedPersons2)
    }

    func mySorted(s1: String, s2: String) -> Bool {
        return s1 < s2
    }

}