quiz.js

class Quiz {
  constructor(questions, timeLimit, timeRemaining) {
    this.questions = questions;
    this.timeLimit = timeLimit;
    this.timeRemaining = timeRemaining;
    this.correctAnswers = 0;
    this.currentQuestionIndex = 0;
  }

  getQuestion() {
    return this.questions[this.currentQuestionIndex];
  }

  moveToNextQuestion() {
    return this.currentQuestionIndex++;
  }

  shuffleQuestions() {
    this.questions.sort(() => Math.random() - 0.5);
  }

  checkAnswer(answer) {
    if (answer === this.getQuestion().answer) {
      this.correctAnswers++;
    }
  }

  hasEnded() {
    if (this.currentQuestionIndex < this.questions.length) {
      return false;
    } else {
      return true;
    }
  }
  filterQuestionsByDifficulty(difficulty) {
    if (typeof difficulty !== "number" || difficulty < 1 || difficulty > 3)
      return;

    this.questions = this.questions.filter((question) => {
      if (difficulty === question.difficulty) {
        return question;
      }
    });
  }
  averageDifficulty() {
    const total = this.questions.reduce(
      (total, question) => total + question.difficulty,
      0
    );
    const average = total / this.questions.length;
    return average;
  }
}