Through SharedPreferences we can store and retrieve key value pair even after closing the app. The key-value pair stored through SharedPreferences are not deleted after closing the app. We need to delete this manually. Lets see how to store, retrieve and delete a key-value pair through SharedPreferences.

First we have to import shared_preferences package. check below

import 'package:shared_preferences/shared_preferences.dart';

Storing key-value pair through SharedPreferences. Check below

Future<void> saveTestValue( String testValue ) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString( "test_value", testValue );
  }

Retrieve key-value pair through SharedPreferences. Check below

Future<String?> getTestValue() async {
    final prefs = await SharedPreferences.getInstance();
    final String? testValue = prefs.getString( "test_value" );
    return testValue;
  }

Deleting key-value pair through SharedPreferences. Check below

Future<void> deleteTestValue() async {
    final prefs = await SharedPreferences.getInstance();
    prefs.remove( "test_value" );
  }