EducaSwift

If you'd like to store simple data permanently on a device to ensure it's available when your app restarts, the best option is to use UserDefaults.

It's important to understand that UserDefaults is not a database and should only be used for saving simple data, such as user preferences (e.g., background color, menu state, etc.).

The types of variables that can be stored include:

• String
• Int
• Float
• Double
• Bool
• Data
• Arrays of the above types
• Dictionaries with the above types

Saving Data

Save data in UserDefaults using the function set(). It requires a unique id as parameter which will be used to load the data we saved.

import Foundation

let username = "Pablo"

UserDefaults.standard.set(username, forKey: "USERNAME_KEY")

Loading Data

To load data we need to use an specific function for that data type. In this case we want to load a String.

import Foundation

let username = UserDefaults.standard.string(forKey: "USERNAME_KEY")

These functions return an Optional value that will be nil in case no value is found for the specified id.

Deleting Data

import Foundation

UserDefaults.standard.removeObject(forKey: "USERNAME_KEY")

UserDefaults containers

UserDefaults.standard is the default container where our data will be stored. However you can use multiple containers in the same App just using specifying a container identifier.

import Foundation

let settingsDefaults = UserDefaults(suiteName: "Settings")
settingsDefaults?.set(false, forKey: "DARK_BACKGROUND")

let profileDefaults = UserDefaults(suiteName: "Profile")
profileDefaults?.set(true, forKey: "AUTO_LOGIN")

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