Question about my solution

function Quiz() {
  this.currentQuestionIndex = 0;
  this.questions = [];
  this.correctAnswers = 0;
  this.addQuestion = (question) => {
    this.questions.push(question);
  };
  this.guess = (response) => {
    if (this.questions[this.currentQuestionIndex].answer === response.toLowerCase()) {
      this.correctAnswers++;
    }
    this.currentQuestionIndex++;
    return this.currentQuestionIndex === this.questions.length;
  }
}

function Question(text, answer, choice0, choice1) {
  this.text = text;
  this.answer = answer;
  this.choice0 = choice0;
  this.choice1 = choice1;
}

const quizDiv = document.getElementById("quiz");
const questionText = document.getElementById("question");
const choice0 = document.getElementById("choice0");
const choice1 = document.getElementById("choice1");
const guessButton0 = document.getElementById("guess0");
const guessButton1 = document.getElementById("guess1");
const progressText = document.getElementById("progress");

quiz = new Quiz();
question0 = new Question("What is my first name?", "sune", "Sune", "Lars");
question1 = new Question("What is my last name?", "justesen", "Andersen", "Justesen");

quiz.addQuestion(question0);
quiz.addQuestion(question1);


const updateUI = () => {
  const currentQuestion = quiz.questions[quiz.currentQuestionIndex]
  questionText.innerHTML = currentQuestion.text;
  choice0.innerHTML = currentQuestion.choice0;
  choice1.innerHTML = currentQuestion.choice1;

  let progressHTML = "Question ";
  progressHTML += quiz.currentQuestionIndex + 1;
  progressHTML += " of ";
  progressHTML += quiz.questions.length;
  progressText.innerHTML = progressHTML;
}

const finish = () => {
  let finishHTML = "<h2>";
  finishHTML += "Your score was ";
  finishHTML += quiz.correctAnswers;
  finishHTML += " out of ";
  finishHTML += quiz.questions.length;
  finishHTML += "</h2>";
  quizDiv.innerHTML = finishHTML;
}

guessButton0.onclick = () => {
  if (quiz.guess(choice0.textContent)) {
    finish();
  } else {
    updateUI();
  }
}

guessButton1.onclick = () => {
  if (quiz.guess(choice1.textContent)) {
    finish();
  } else {
    updateUI();
  }
}

updateUI();