advanced_quiz_app

To create this app I navigated to the project folder then type this command on the terminal

flutter create adv_quiz_app

// flutter create <app_name>

After this is created, navigate to adv_quiz_app and to start/launch your Linux app locally run:

flutter run

A new Flutter project.

Getting Started

This project is a starting point for a Flutter application.

A few resources to get you started if this is your first Flutter project:

For help getting started with Flutter development, view the online documentation, which offers tutorials, samples, guidance on mobile development, and a full API reference.

Flutter's (Stateful) Widget Lifecycle

Every Flutter Widget has a built-in lifecycle: A collection of methods that are automatically executed by Flutter (at certain points of time).

There are three extremely important (stateful) widget lifecycle methods:

initState(): Executed by Flutter when the StatefulWidget's State object is initialized
build(): Executed by Flutter when the Widget is built for the first time AND after setState() was called
dispose(): Executed by Flutter right before the Widget will be deleted (e.g., because it was displayed conditionally)

Using "if" Statements In Lists

Comparison Operators

== operator checks for value equality
!= to check for inequality (randomNumber != 5 expects randomNumber to NOT be 5, i.e., to be any other value)
> to check for the value on the left to be greater than the value on the right (randomNumber > 5 yields true if randomNumber is greater than 5)
>= to check for the value on the left to be greater than or equal to the value on the right (randomNumber >= 5 yields true if randomNumber is greater than 5 or equals 5)
< to check for the value on the left to be smaller than the value on the right (randomNumber < 5 yields true if randomNumber is smaller than 5)
<= to check for the value on the left to be smaller than or equal to the value on the right (randomNumber <= 5 yields true if randomNumber is smaller than 5 or equals 5)

Fonts & Styling

Adding custom fonts

Misc - Important Dart Features

Getters

The following function of getSummaryData can be re-written as a getter as shown further below.

class ResultsScreen extends StatelessWidget {
  const ResultsScreen({
    super.key,
    required this.chosenAnswers,
    required this.onRestart,
  });

  final List<String> chosenAnswers;
  final void Function() onRestart;

  List<Map<String, Object>> getSummaryData() {
    final List<Map<String, Object>> summary = [];

    for (var i = 0; i < chosenAnswers.length; i++) {
      summary.add(
        {
          'question_index': i,
          'question': questions[i].text,
          'correct_answer': questions[i].answers[0],
          'user_answer': chosenAnswers[i],
        },
      );
    }

    return summary;
  }

The get keyword is used and the parentheses used earlier on are omitted

class ResultsScreen extends StatelessWidget {
  const ResultsScreen({
    super.key,
    required this.chosenAnswers,
    required this.onRestart,
  });

  final List<String> chosenAnswers;
  final void Function() onRestart;

  List<Map<String, Object>> get summaryData { // changed
    final List<Map<String, Object>> summary = [];

    for (var i = 0; i < chosenAnswers.length; i++) {
      summary.add(
        {
          'question_index': i,
          'question': questions[i].text,
          'correct_answer': questions[i].answers[0],
          'user_answer': chosenAnswers[i],
        },
      );
    }

    return summary;
  }

  @override
  Widget build(BuildContext context) {
    final numTotalQuestions = questions.length;
    final numCorrectQuestions = summaryData.where((data) { // changed
      return data['user_answer'] == data['correct_answer'];
    }).length;

    return ...rest of the code
}

NSM722/Flut-Quiz