Flutter developer interview questions

Hiring the right Flutter developer is as simple as using skills tests first and then using Flutter developer interview questions during the interview stage.

#1 True or false? Flutter apps are rendered by the platforms on which they run, such as Android, desktop, iOS, and the web.

Ans:

false

Flutter apps are not rendered by the platforms on which they run. Instead, Flutter uses its own rendering engine to create a consistent UI experience across different platforms. This allows Flutter apps to look and feel consistent on Android, desktop, iOS, and the web, even though they are not directly using the native platform's rendering mechanisms.

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#2 _ widgets maintain state that might change during the lifetime of the widget.

Ans:

Stateful widgets maintain state that might change during the lifetime of the widget. Implementing a stateful widget requires a StatefulWidget class that creates an instance of a State class. The StatefulWidget class is immutable, but the State class persists over the lifetime of the widget.

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#3 In Flutter's reactive-style framework, calling ___ triggers a call to the build() method for the State object, resulting in an update to the UI.

Ans:

In Flutter's reactive-style framework, calling setState() triggers a call to the build() method for the State object, resulting in an update to the UI.

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#4 Dart supports which of the following functional-programming features?

Ans:

Passing functions as arguments

void main() {
  void greet(String name) {
    print('Hello, $name!');
  }

  void processGreeting(Function greetingFunction, String name) {
    greetingFunction(name);
  }

  processGreeting(greet, 'Alice');
}

..

Assigning functions to variables

void main() {
  String greet(String name) {
    return 'Hello, $name!';
  }

  var greetingFunction = greet;
  print(greetingFunction('Bob'));
}

..

Deconstructing functions that take multiple arguments into sequences of functions that each take single arguments

void main() {
  int add(int a, int b) {
    return a + b;
  }

  Function curriedAdd = (int a) => (int b) => add(a, b);

  var add5 = curriedAdd(5);
  print(add5(3)); // Outputs: 8
}

..

Creating nameless functions that can be used as constant values

void main() {
  var square = (int x) => x * x;

  print(square(4)); // Outputs: 16
}

..