Ans.Flutter is a UI toolkit from Google for building natively compiled applications for mobile, web, and desktop from a single codebase.
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Explain the difference between StatelessWidget and StatefulWidget in Flutter.Ans.StatelessWidget is immutable, meaning its properties can't change once initialized. StatefulWidget, however, can maintain state, allowing for dynamic UI updates.
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What is a Widget in Flutter?Ans.In Flutter, everything is a widget. Widgets are the basic building blocks of UI elements, such as buttons, text, layout, etc.
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What is the purpose of the main() function in Flutter?Ans.The main() function is the entry point of a Flutter application. It calls the runApp() function to run the app's root widget.
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Explain hot reload in Flutter.Ans.Hot reload allows developers to quickly see the effects of code changes without restarting the app, speeding up the development process.
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What is the purpose of the pubspec.yaml file in Flutter projects?Ans.The pubspec.yaml file is used to define dependencies, assets, and metadata for a Flutter project. It manages project dependencies and configuration.
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What are some advantages of using Flutter for mobile app development?Ans.Flutter offers hot reload for rapid development, a single codebase for multiple platforms, high performance due to its compiled nature, and a rich set of customizable widgets.
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Explain the concept of 'Widgets as Building Blocks' in Flutter.Ans.In Flutter, UI elements are built using widgets, which are composed together to create complex layouts. Widgets can be nested within each other to create a UI hierarchy.
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What is the purpose of the 'setState()' method in Flutter?Ans.The 'setState()' method notifies Flutter that the internal state of a State object has changed, triggering a rebuild of the UI based on the new state data.
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What is the 'BuildContext' class in Flutter?Ans.BuildContext represents the location of a widget in the widget tree. It's used to locate parent widgets or find the nearest instance of a specific type of widget.
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Explain the concept of 'Material Design' in the context of Flutter.Ans.Material Design is a design language developed by Google that provides guidelines and components for creating visually appealing and consistent UI across different platforms.
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What is the purpose of the 'async' and 'await' keywords in Dart?Ans.The 'async' keyword is used to mark a function as asynchronous, allowing it to use the 'await' keyword to pause execution until an asynchronous operation completes.
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Explain the difference between 'mainAxisSize' and 'crossAxisAlignment' in Flutter's Row and Column widgets.Ans.'mainAxisSize' defines the size of the Row or Column along its main axis, while 'crossAxisAlignment' determines how children are aligned along the cross axis.
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What is a 'PageRoute' in Flutter?Ans.A 'PageRoute' represents a screen or page in a Flutter app. It facilitates navigation between different screens using transitions such as sliding, fading, or scaling.
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How can you handle user input in Flutter?Ans.User input in Flutter can be handled using GestureDetector for detecting gestures like taps, swipes, etc., or using various input widgets like TextField, Checkbox, and Button.
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Explain the purpose of the 'Future' class in Dart.Ans.A 'Future' represents a potential value or error that will be available at some time in the future. It's commonly used for asynchronous programming to handle operations that may take time to complete.
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What is a 'Widget tree' in Flutter?Ans.A 'Widget tree' is a hierarchical structure of widgets representing the UI of a Flutter application. It describes how widgets are nested and composed together to build the UI.
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How can you handle app lifecycle events in Flutter?Ans.In Flutter, you can use the 'WidgetsBindingObserver' mixin to observe lifecycle events such as 'didChangeAppLifecycleState' and handle them accordingly, like pausing a video when the app enters the background.
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What is the purpose of the 'Key' class in Flutter?Ans.The 'Key' class in Flutter is used to uniquely identify widgets. It's particularly useful when working with lists or when you need to maintain state across widget rebuilds.
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Explain the concept of 'InheritedWidget' in Flutter.Ans.'InheritedWidget' is a special type of widget in Flutter that allows data to be passed down the widget tree to its descendants efficiently, without the need to rebuild all the widgets in between.
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What is the purpose of the 'Navigator' class in Flutter?Ans.The 'Navigator' class manages a stack of 'Route' objects and facilitates navigation between different screens or pages in a Flutter app.
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What is the 'BuildContext' and why is it important in Flutter?Ans.BuildContext represents the location of a widget in the widget tree and is crucial for accessing properties of parent widgets or finding the nearest instance of a specific type of widget.
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Explain the concept of 'State Management' in Flutter.Ans.State management in Flutter involves managing the state of a widget or an application and updating the UI in response to changes. It's essential for building dynamic and interactive user interfaces.
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What are some commonly used state management solutions in Flutter?Ans.Popular state management solutions in Flutter include Provider, Redux, BLoC (Business Logic Component), MobX, and setState(). Each has its own set of features and use cases.
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What is the purpose of the 'BuildContext' parameter in the 'build()' method of a widget?Ans.The 'BuildContext' parameter provides information about the location of the widget in the widget tree. It's necessary for accessing properties of ancestor widgets or finding child widgets.
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Explain the concept of 'Widget Lifecycle' in Flutter.Ans.The widget lifecycle in Flutter consists of various stages such as 'initState()', 'didUpdateWidget()', 'dispose()', etc., which are called at different points during the widget's existence to handle initialization, updates, and cleanup.
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How can you handle orientation changes in Flutter?Ans.You can handle orientation changes in Flutter by listening to the 'OrientationBuilder' widget or using the 'MediaQuery' class to get the current device orientation and adjust the UI accordingly.
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What are some techniques for optimizing performance in a Flutter app?Ans.Performance optimization techniques in Flutter include minimizing widget rebuilds, using const constructors, reducing unnecessary animations, lazy-loading data, and using the 'Flutter DevTools' for profiling and debugging.
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Explain the concept of 'GlobalKey' in Flutter.Ans.'GlobalKey' is a special type of key that allows access to a widget from anywhere in the widget tree. It's commonly used for managing state or accessing properties of widgets across different parts of the app.
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What is the purpose of the 'Builder' widget in Flutter?Ans.The 'Builder' widget in Flutter is used to construct a subtree of widgets within the context of a 'BuildContext'. It's particularly useful when you need to access properties of a parent widget inside a 'build()' method.
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How can you add custom fonts to a Flutter app?Ans.You can add custom fonts to a Flutter app by specifying them in the 'pubspec.yaml' file and then referencing them using the 'TextStyle' class in your Flutter code.
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Explain the concept of 'Flutter Packages'.Ans.Flutter packages are reusable libraries of code and assets that can be easily added to Flutter projects to extend functionality. They are published on 'pub.dev' and can be installed using the 'flutter pub' command.
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What is the purpose of the 'SingleChildScrollView' widget in Flutter?Ans.The 'SingleChildScrollView' widget in Flutter allows its child to be scrolled in a single axis, either vertically or horizontally, when the content exceeds the available space.
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Explain the concept of 'InheritedWidget' and 'InheritedModel' in Flutter.Ans.'InheritedWidget' and 'InheritedModel' are used for efficiently passing data down the widget tree to its descendants. 'InheritedWidget' is a general-purpose solution, while 'InheritedModel' allows more granular control over which descendants should update.
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What is the purpose of the 'Flexible' widget in Flutter's layout system?Ans.The 'Flexible' widget in Flutter is used to control how a child widget flexes to fill the available space within a 'Flex' container, allowing for more dynamic and responsive layouts.
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Explain the concept of 'Theme' in Flutter and how it's used.Ans.'Theme' in Flutter allows you to define a set of consistent visual properties like colors, typography, and shapes that can be applied to all or part of your app. It helps maintain a consistent look and feel throughout the application.