Flutter key points mostly asked in flutter interviews

Here’s a comprehensive list of key points that are frequently asked in Flutter interviews, covering both basic and advanced topics. These points are categorized for better clarity:

1. Flutter Basics

• What is Flutter?
  • Open-source UI toolkit by Google for building natively compiled applications for mobile, web, and desktop from a single codebase.
• What is Dart?
  • Language used by Flutter, optimized for fast apps on multiple platforms.
• Main components of Flutter
  • Widgets, Elements, Render Objects
• Difference between Hot Reload & Hot Restart
  • Hot reload: Injects updated code into the running app.
  • Hot restart: Rebuilds the app from scratch.
• StatelessWidget vs StatefulWidget
  • Stateless: immutable, no internal state.
  • Stateful: maintains mutable state.
• Widget lifecycle
  • createState, initState, build, didUpdateWidget, dispose

2. UI & Widgets

• Common Widgets
  • Container, Row, Column, Stack, ListView, Text, Image, etc.
• Layout and Constraints
  • Flutter uses constraints to define UI layout.
  • Parent sets constraints, child chooses size.
• ListView vs Column
  • ListView is scrollable; Column is not.
• Custom Widgets
  • Creating reusable widget components.
• InheritedWidget / Provider
  • State sharing higher up in the widget tree.

3. State Management

• Why state management is important?
  • Helps manage and update UI based on user interaction or data changes.
• Popular approaches
  • setState, Provider, Riverpod, Bloc, GetX, MobX, Redux
• When to use setState vs Provider/Bloc?
  • setState: for local widget state.
  • Provider/Bloc: for app-wide or complex state.

4. Navigation & Routing

• Navigator 1.0 vs Navigator 2.0
  • Navigator 1.0: Stack-based imperative API.
  • Navigator 2.0: Declarative API (useful for web).
• Named routes vs anonymous routes
• Passing data between screens

5. Networking

• HTTP requests with http package
• Dio package for advanced networking
• Handling JSON (parsing, serialization)
• Using FutureBuilder for async data

6. Local Storage

• SharedPreferences
  • For small key-value data.
• Hive
  • Lightweight NoSQL DB.
• Sqflite
  • SQLite DB for structured data.

7. Integrations & Plugins

• Popular Plugins
  • url_launcher, path_provider, camera, image_picker, firebase, etc.
• Platform-specific code
  • MethodChannels for native Android/iOS code.

8. Firebase Integration

• Firebase Authentication
• Cloud Firestore / Realtime Database
• Firebase Cloud Messaging (Push Notifications)
• Firebase Storage

9. Testing

• Flutter test packages
  • flutter_test, mockito, integration_test
• Types of testing
  • Unit testing
  • Widget testing
  • Integration testing

10. Advanced Concepts

• Isolates in Dart
  • For running expensive tasks in parallel.
• Streams & Futures
  • Handling asynchronous data and real-time updates.
• Flutter DevTools
  • Performance profiling, widget inspector, etc.
• Animations in Flutter
  • AnimatedContainer, TweenAnimationBuilder, AnimationController
• Custom Paint & Canvas
  • Drawing graphics and shapes manually.

11. Performance Optimization

• Widget rebuilding
• Using const constructors
• Avoiding unnecessary rebuilds
• Using RepaintBoundary

12. Deployment

• Building APK / AAB for Android
• iOS setup and deployment
• Code signing and provisioning profiles

13. Interview Questions Examples

Basic

• What is a Widget in Flutter?
• Explain the build context.
• Difference between hot reload and hot restart.

Intermediate

• How does Flutter render UI?
• When would you use a FutureBuilder?
• How do you manage state in a large Flutter app?

Advanced

• How does the Flutter rendering pipeline work?
• Compare Bloc vs Provider.
• How to write a custom InheritedWidget?