Flutter developer exams

Flutter's core is built on widgets, the fundamental building blocks of any Flutter application. Think of a widget as a description of a UI element – its logic, how it interacts, and its visual design. This approach is similar to how React works.

What sets Flutter apart is its rendering engine. Unlike cross-platform frameworks like React Native and Xamarin that rely on native platform components, Flutter renders widgets directly on the screen, pixel by pixel. This gives Flutter incredible control over the UI.

There are two main types of widgets in Flutter:

• Stateless Widgets: These widgets are simple and only update when their input data changes. They are efficient because they don't need to be rebuilt when other parts of the screen are updated.
• Stateful Widgets: These widgets have an internal state that can change. You can use the setState() method to trigger a redraw when the state changes, allowing for dynamic and interactive UIs.

While widgets are the primary way to build Flutter apps, you can also bypass them and draw directly on a canvas. This is sometimes used for performance-critical applications like game engines within Flutter.

Flutter provides two distinct sets of widgets, each adhering to a specific design language:

• Material Design Widgets: Implement Google's Material Design, providing a familiar and consistent look and feel.
• Cupertino Widgets: Follow Apple's iOS Human Interface Guidelines, offering a native iOS experience.

A powerful feature of Flutter is its flexibility – you can use either set of widgets on either Android or iOS, allowing for consistent UI design across platforms. You can even use Cupertino widgets on Android to achieve a distinct iOS-like appearance.