How to save local data in a Swift app?

The Solution to How to save local data in a Swift app? is


The simplest solution if you are just storing two strings is NSUserDefaults, in Swift 3 this class has been renamed to just UserDefaults.

It's best to store your keys somewhere globally so that you can reuse them elsewhere in your code.

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.

~ Answered on 2015-02-20 12:15:09


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