如果仅存储两个字符串NSUserDefaults，最简单的解决方案是，在Swift 3中，该类已重命名为just UserDefaults。

最好将密钥存储在全局位置，以便您可以在代码的其他位置重用它们。

struct defaultsKeys {
    static let keyOne = "firstStringKey"
    static let keyTwo = "secondStringKey"
}

Swift 3.0, 4.0 & 5.0

// Setting

let defaults = UserDefaults.standard
defaults.set("Some String Value", forKey: defaultsKeys.keyOne)
defaults.set("Another String Value", forKey: defaultsKeys.keyTwo)

// Getting

let defaults = UserDefaults.standard
if let stringOne = defaults.string(forKey: defaultsKeys.keyOne) {
    print(stringOne) // Some String Value
}
if let stringTwo = defaults.string(forKey: defaultsKeys.keyTwo) {
    print(stringTwo) // Another String Value
}

Swift 2.0

// Setting

let defaults = NSUserDefaults.standardUserDefaults()
defaults.setObject("Some String Value", forKey: defaultsKeys.keyOne)
defaults.setObject("Another String Value", forKey: defaultsKeys.keyTwo)

// Getting

let defaults = NSUserDefaults.standardUserDefaults()
if let stringOne = defaults.stringForKey(defaultsKeys.keyOne) {
    print(stringOne) // Some String Value
}
if let stringTwo = defaults.stringForKey(defaultsKeys.keyTwo) {
    print(stringTwo) // Another String Value
}

For anything more serious than minor config, flags or base strings you should
use some sort of persistent store - A popular option at the moment is
Realm but you can also use
SQLite or Apples very own
CoreData.