Flutter Interview Questions & Answers – Chetu Company Preparation

Flutter is one of the fastest-growing frameworks for cross-platform app development. If you are preparing for an interview (like with Chetu Company), here’s a complete list of commonly asked Flutter Interview Questions & Answers to help you revise quickly.

🔹 1. What is State Management in Flutter?

State management is how you manage and update the data that affects your UI. It ensures the UI automatically reflects changes in the application state.

<img src="Chetu Flutter Interview Questions.png" alt="Chetu Flutter Interview Questions">

🔹 2. Why not always use setState?

🔹 3. Package vs Plugin in Flutter

🔹 4. What are Keys in Flutter?


Keys are used to preserve widget state when widgets are rebuilt, especially in lists. They help Flutter differentiate between widgets with the same type.

🔹 5. Stream in Flutter (Key Points)

🔹 6. Stateful vs Stateless Widget

🔹 7. Stateful Widget Lifecycle Explanation

  1. createState → Creates state object.
  2. initState → Called once, good for initialization.
  3. didChangeDependencies → Called when dependencies change.
  4. build → Builds the widget tree.
  5. didUpdateWidget → Called when widget config changes.
  6. setState → Triggers UI rebuild.
  7. deactivate → Called when widget is removed from tree.
  8. dispose → Cleanup before widget is destroyed.

🔹 8. What is a Mixin in Flutter?

A way to reuse a class’s code in multiple class hierarchies. It allows adding functionality without inheritance.

🔹 9. What is Extension in Flutter?

Extensions add new methods/properties to existing classes without modifying their source code.

🔹 10. What is ChangeNotifier?

A simple class for state management that notifies listeners when notifyListeners() is called.

🔹 11. What is Dependency Injection?

A design pattern where objects are provided their dependencies instead of creating them internally, improving reusability and testability.

🔹 12. ListView vs ListView.builder (Key Points)

🔹 13. What is Tree Shaking?

A Dart/Flutter compiler optimization that removes unused code from the final build, reducing app size.

🔹 14. Method Channel (Key Points)

🔹 15. Firebase Notifications in Flutter

Firebase Cloud Messaging (FCM) allows sending push notifications to Android/iOS apps using Firebase.

🔹 16. How to Use Firebase Notifications?

  1. Add firebase_core and firebase_messaging packages.
  2. Initialize Firebase in main.dart.
  3. Request notification permissions.
  4. Use FirebaseMessaging.onMessage and FirebaseMessaging.onBackgroundMessage to handle notifications.

🔹 17. Async & Await in Flutter

🔹 18. MaterialApp vs Scaffold

🔹 19. About Flutter

Flutter is an open-source framework by Google for building cross-platform apps (Android, iOS, Web, Desktop) using a single codebase. It uses the Dart language and provides fast performance with a widget-based architecture.

🔹 20. How to Remove Debug Banner in Flutter?

MaterialApp(
  debugShowCheckedModeBanner: false,
);

✨ Final Note:
These questions are commonly asked in Flutter interviews at Chetu and other companies. Revising them will boost your confidence and help you give crisp, clear answers.

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