Userdefault-2019-01-17

let fir = UserDefaults.init(suiteName: "ViewController")
fir?.set("1", forKey: "test")

    let sec = UserDefaults.init(suiteName: "ViewController")
    print(sec?.value(forKey: "test"))
    Optional(1)
    sec?.set("2", forKey: "test")
    print(fir?.value(forKey: "test"))
    Optional(2)

结论：Userdefaults suiteName一致时，数据统一存储

参考：https://www.jianshu.com/p/8cb9661fc9d3