What is SharedPreferences?
SharedPreferences is used for storing data key-value pair in the Android and iOS.
SharedPreferences in flutter uses NSUserDefaultson iOS and SharedPreferences on Android, providing a persistent store for simple data.
Why use SharedPreferences in Flutter?
Suppose you wanna save a small value (a flag probably) that you wanna refer later sometime when a user launches the application. Then shared preference comes into action.
We do not use SQLite for saving small values because then you will need to write lengthy codes and supporting classes.
Shared Preference let you read and write key-value pair in a couple of lines easily. But always remember, shared preference is not a solution for you to keep complex relational data.
How to use SharedPreferences in Flutter?
Before using SharedPreferences, you should know that Flutter SDK does not have support SharedPreferences but fortunately, the shared_preferences plugin can be used to persist key-value data on disk.
Implementation
Step 1: Add the dependencies
Add dependencies to pubspec.yaml file.
dependencies:
flutter:
sdk: flutter
shared_preferences: "<newest version>"Step 2: Import shared_preferences.dart
import 'package:shared_preferences/shared_preferences.dart';Step 3: Save data
We can only add int, String, double and bool using SharedPreferences.
There are setter methods in the SharedPreferences class which take two parameters, key and value.
keys are only string values
Saving String value
https://gist.github.com/ashishrawat2911/0cdad3ca524d06a455d0986687567848#file-addstringsf-dart
Saving int value
https://gist.github.com/ashishrawat2911/d57dbfd9fc465cfe1c20f65be725cef2#file-addintsf-dart
Saving double value
https://gist.github.com/ashishrawat2911/bac6897604ac01b544915a3ef25c4aff#file-adddoublesf-dart
Saving boolean value
https://gist.github.com/ashishrawat2911/362c16deae76b40b8d2b357ebc68269c#file-addboolsf-dart
Step 4: Read data
When we are reading the data from the storage through SharedPreferences we only required to pass the key only.
https://gist.github.com/ashishrawat2911/2bc3d85c0a31bd1c2bf9009a8f865f88#file-readvaluessf-dart
If the value is not present in the storage then we might get a null value.
To handle this we can use
intintValue= await prefs.getInt('intValue') ?? 0;
Step 5: Remove data
To remove the data from the storage we provide the key in the remove(String key) method.
https://gist.github.com/ashishrawat2911/e9ba0b8bc3fcf1aae1fe7c2ca78cfc2d#file-removevaluessf-dart
Check value if present or not?
SharedPreferences prefs = await SharedPreferences.getInstance();containsKey
bool CheckValue = prefs.('value');
containsKey will return true if persistent storage contains the given key and false if not.
Thanks for reading this article ❤
Connect with me on Linkedin and Github
From Our Parent Company Aeologic
Aeologic Technologies is a leading AI-driven digital transformation company in India, helping businesses unlock growth with AI automation, IoT solutions, and custom web & mobile app development. We also specialize in AIDC solutions and technical manpower augmentation, offering end-to-end support from strategy and design to deployment and optimization.
Trusted across industries like manufacturing, healthcare, logistics, BFSI, and smart cities, Aeologic combines innovation with deep industry expertise to deliver future-ready solutions.
Feel free to connect with us:
And read more articles from FlutterDevs.com.
FlutterDevs team of Flutter developers to build high-quality and functionally-rich apps. Hire a flutter developer for your cross-platform Flutter mobile app project on an hourly or full-time basis as per your requirement! You can connect with us on Facebook, GitHub, Twitter, and LinkedIn for any flutter-related queries.
We welcome feedback and hope that you share what you’re working on using #FlutterDevs. We truly enjoy seeing how you use Flutter to build beautiful, interactive web experiences.
Related: SMS Using Twilio In Flutter
Related: Working with Callback In Flutter
Frequently Asked Questions
How can I save user data like preferences or login status in a Flutter app?
You can use SharedPreferences, a built-in package in Flutter, to store small amounts of persistent data on the device.
What is the process for setting and retrieving data using SharedPreferences in Flutter?
You can use `setString`, `setInt`, `setBool`, etc., to store data, and `getString`, `getInt`, `getBool` to retrieve it.
How secure is the data stored using SharedPreferences in Flutter?
Data stored with SharedPreferences is not encrypted, so it’s recommended to use it for simple user preferences and not sensitive information.
