Top 10 interview questions for Flutter developer

Flutter is a rapidly growing cross-platform mobile, web, desktop application development UI toolkit by Google. The Flutter developer community is also growing day by day, and many job opportunities create for Flutter developer. It's important to know about the most frequently asked interview question about Flutter so that you can be more confident about asked question when you seat for an interview.

01. What is Flutter?

Answer: According to flutter.dev, Flutter is Google's UI toolkit for building cross-platform mobile, web, desktop application with a single codebase.

02. What is the Flutter widget?

Answer: In Flutter every component considered a widget like text, container, row, column, style and so on. A flutter app builds with a widget tree. There are two types of widgets in Flutter, Stateless widgets and Stateful Widgets.

03. What are the advantages of Flutter?

Answer: Advantages of Flutter are _

• It's cross-platform so that we can make an app for android, ios, web or even desktop application with a single codebase.
• Rapid performant application development.
• Hot and live reloading make app changes easier during development without compromising the application state.
• Good official documentation.
• Growing flutter community.
• It open-sources and maintained by Google.

04. What is Dart?

Answer: Dart is an open-source object-oriented programming language developed by Google in 2011. Flutter uses Dart language for application development.

05. What is a stateful and stateless widget?

Answer: Stateless Widgets: Stateless widget which does not hold the state information of application and will not rebuild widgets when application state change happened.

Stateful Widgets: Stateful Widgets has the state information of an application and the widgets are rebuilt when a certain application state change occurred.

06. What is the BuildContext in Flutter?

Answer: It's a part of widgets in the element tree. In flutter, every widget has its own build context.

07. What is null safety in Flutter?

Answer: It helps to disappear the null related errors at runtime. From Flutter 2 and dart 2.12, the null safety introduced. Learn more about Null safety.

08. What is the main difference between Hot restart and Hot reload?

Answer:

Hot reload: It compiles the newly added code and reflect it instantly into UI without changing the application state. Hot reload perform by pressing r in the command prompt.

Hot restart: It completely rebuilds the entire application code by resetting the application state. It takes a longer time than the hot reload. It performed by pressing Ctrl+R.

09. What is the command to check the Flutter development environment?

Answer: flutter doctor is the command to check the development environment is okay or not.

10. What is the current version of Flutter and Dart?

Answer: Flutter: 2.2.2 and Dart: 2.13.3 (When this article written)