10+ android and Flutter Developer Interview Questions and Answers

Stateful widgets maintain state across rebuilds, while stateless widgets do not and are immutable.

• StatefulWidget: Can change its state during its lifecycle. Example: Checkbox, TextField.

• StatelessWidget: Immutable and does not hold state. Example: Text, Icon.

• Stateful widgets require a createState() method to manage state.

• Stateless widgets are simpler and faster to build since they don't manage state.

State management in Flutter is done using various approaches like setState, InheritedWidget, Provider, BLoC, Redux, etc.

• setState is the simplest approach for small apps with few widgets.

• InheritedWidget is used for sharing data across the widget tree.

• Provider is a popular state management solution that uses InheritedWidget internally.

• BLoC (Business Logic Component) separates business logic from UI and uses Streams to manage state.

• Redux is a predictable state container that use...read more

Code for swapping two numbers using two variables only

• Use a temporary variable to store the value of one variable

• Assign the value of the second variable to the first variable

• Assign the value of the temporary variable to the second variable

Bloc is a state management library for Flutter that helps manage the flow of data and events.

• Bloc stands for Business Logic Component.

• It helps separate the presentation layer from the business logic.

• Bloc is commonly used with Flutter to handle state management and data flow.

• It uses streams to handle asynchronous data and events.

• Bloc pattern consists of events, states, and a bloc class to handle the business logic.

Java interface is a blueprint of a class that has only abstract methods and constants.

• An interface is declared using the interface keyword

• It cannot be instantiated directly

• It can be implemented by a class using the implements keyword

• All methods in an interface are public and abstract by default

• Interfaces can also have static and default methods

• Example: public interface Drawable { void draw(); }

A StreamBuilder is a Flutter widget that builds itself based on the latest snapshot of interaction with a Stream.

• It listens to a Stream and rebuilds its child widget whenever new data is emitted.

• Useful for displaying real-time data, such as chat messages or live updates.

• Example: StreamBuilder<String>( stream: myStream, builder: (context, snapshot) { if (snapshot.connectionState == ConnectionState.waiting) { return CircularProgressIndicator(); } return Text(snapshot.data); }, ...read more

Dart is a programming language used for building mobile, web, and desktop applications. Pattern refers to a reusable solution to a common problem.

• Dart is an object-oriented language developed by Google.

• It is used to build applications for Android, iOS, web, and desktop platforms.

• Dart is known for its fast performance and easy-to-learn syntax.

• Design patterns are reusable solutions to common software design problems.

• They provide a structured approach to solving problems and imp...read more

Flutter is a UI toolkit for building natively compiled applications for mobile, web, and desktop from a single codebase. State refers to the data that can change over time in an application.

• Flutter is a framework developed by Google for building cross-platform applications.

• It uses a single codebase to create apps for Android, iOS, web, and desktop.

• State in Flutter represents the data that can change over time in an application.

• Flutter provides various ways to manage and updat...read more

State management is a crucial aspect of app development to handle and update the state of the application.

• Local State Management: Managing state within a widget using setState() method.

• InheritedWidget: Sharing state across the widget tree using InheritedWidget.

• Provider: A popular state management solution that uses InheritedWidget under the hood.

• Redux: A predictable state container for managing the state of the app.

• Bloc: A state management solution that uses streams and sinks...read more

State management techniques are used to manage the state of an application in a predictable and efficient manner.

• Stateful widgets in Flutter can manage their own state internally.

• Provider package in Flutter allows for a simple and efficient way to manage state.

• Redux is a popular state management library for managing state in Android applications.

StatefulWidget is a class in Flutter that can hold state and can be rebuilt multiple times.

• StatefulWidget is used when the UI needs to dynamically change based on user interactions or data changes.

• It consists of two classes - StatefulWidget and State.

• StatefulWidget is immutable, while State is mutable and holds the widget's state.

• setState() method is used to notify Flutter that the widget's state has changed and needs to be rebuilt.

• Example: TextField widget in Flutter is a St...read more

My expected CTC is based on my experience, skills, and the industry standards.

• My expected CTC is in line with the current market rates for Android and Flutter developers.

• I have taken into consideration my years of experience and expertise in the field.

• I am open to negotiation based on the overall compensation package offered by the company.

Flutter is a mobile app SDK for building high-performance, high-fidelity, apps for iOS and Android, from a single codebase.

• Flutter is developed by Google and uses Dart programming language.

• It allows for hot reload, which means developers can see the changes they make in real-time.

• Flutter has its own set of customizable widgets and also supports Material Design and Cupertino widgets.

• It has a reactive programming model and supports asynchronous programming.

• Flutter is used by po...read more

Flutter is an open-source UI software development kit created by Google for building natively compiled applications for mobile, web, and desktop from a single codebase.

• Flutter is used to develop cross-platform applications.

• It uses the Dart programming language.

• Flutter provides a rich set of pre-designed widgets for building user interfaces.

• It allows hot-reloading, enabling developers to see the changes instantly.

• Flutter apps can be built for Android, iOS, web, and desktop pla...read more

Stateful widgets in Flutter have a lifecycle that includes various methods being called at different stages.

• Stateful widgets have methods like initState(), didChangeDependencies(), build(), and dispose() that are called at different points in the widget's lifecycle.

• initState() is called when the widget is inserted into the tree, didChangeDependencies() is called when the widget's dependencies change, build() is called to build the widget's UI, and dispose() is called when the...read more

Provider and GetX are state management solutions for Flutter. Provider is more flexible and requires more boilerplate code, while GetX is simpler and more concise.

• Provider requires more boilerplate code compared to GetX

• GetX is simpler and more concise than Provider

• Provider is more flexible and allows for more customization

• GetX provides built-in functionalities like state management, dependency injection, and routing

• GetX is known for its performance and ease of use