Kotlin SharedPreferences

SharedPreferences is a simple key/value store in Android that allows you to save and store data across the lifecycle of an application. In this tutorial, we will be discussing how to use SharedPreferences using Kotlin.

Syntax

To create a SharedPreferences object in Kotlin, you can use the following syntax:

val sharedPreferences = context.getSharedPreferences(name, mode)

Here, "name" is the name of the SharedPreferences file and "mode" specifies the mode of the file.

Example

Let's say we want to store a string and a boolean value in SharedPreferences. We can use the following code:

val sharedPreferences = context.getSharedPreferences("MyPreferences", Context.MODE_PRIVATE)
val editor = sharedPreferences.edit()
editor.putString("name", "John")
editor.putBoolean("isMarried", true)
editor.apply()

In the example above, we create a SharedPreferences object with the name "MyPreferences" and the private mode. We then create an editor object using the SharedPreferences.edit() method, modify its contents, and apply changes using the apply() method.

Output

There is no output when using SharedPreferences directly. The values are simply stored in the SharedPreferences file and can be retrieved later.

Explanation

SharedPreferences can be used to store simple data types such as strings, integers, booleans, and floats. To use SharedPreferences, you first need to create a SharedPreferences object using the context of your application. You can then use an editor object to modify and save data to the SharedPreferences file.

When saving data, you use the put*() methods to store data for a specific key. When retrieving data, you use the get*() methods to retrieve a value for a specific key.

Use

SharedPreferences can be used to store and retrieve small amounts of data necessary for the application's functionality. For example, you could use SharedPreferences to store the user's preferences, their name, and other basic settings.

Important Points

• SharedPreferences should not be used to store large amounts of data.
• All values stored in SharedPreferences are accessible by any component in the application.
• To delete a value from SharedPreferences, use the remove() method.

Summary

In this tutorial, we discussed how to use SharedPreferences in Kotlin. We covered the syntax, example, output, explanation, use, and important points of using SharedPreferences to store and retrieve data. With this knowledge, you can now use SharedPreferences in your Kotlin applications to store and retrieve small amounts of data.