SwiftyUserDefaults-封装系统本地化的框架推荐

 //
 //  ViewController.swift
 //  Test4SwiftyUserDefaults
 // //  Copyright © 2017年. All rights reserved.
 //

 import UIKit

 class ViewController: UIViewController {

   override func viewDidLoad() {
     super.viewDidLoad()
       Defaults[.userID] = "lilei";
     Defaults[.age] =
     Defaults[.age] +=
      print(Defaults[.userID])
     print(Defaults[.age])
   }

 }

 extension DefaultsKeys{
   static let userID = DefaultsKey<String>("userID")
   static let age = DefaultsKey<Int>("age")
 }

详见  https://github.com/radex/SwiftyUserDefaults