​

let oldQuestionIndex = -1;

​

const labelAnswerA = document.getElementById('label-answer_A');

const labelAnswerB = document.getElementById('label-answer_B');

const labelAnswerC = document.getElementById('label-answer_C');

const labelAnswerD = document.getElementById('label-answer_D');

​

let arrAnswerVaranty = ['a', 'b', 'c', 'd'];

​

const btnSubmit = document.querySelector('.btn-submit');

​

const quizArr = [{

    question: 'What is the most used programming language in 2019?',

    answers: ['Java', 'C', 'Python', 'JS']

  },

  {

    question: 'Who is the President of US?',

    answers: ['Florin Pop', 'Joe Biden', 'Ivan Saldano', 'Mihai Andrei']

  },

  {

    question: 'What does HTML stand for?',

    answers: [

      'Hypertext Markup Language',

      'Cascading Style Sheet',

      'Jason Object Notation',

      'Helicopters Terminals Motorboats Lamborgini'

    ]

  },

  {

    question: 'What year was JavaScript launched?',

    answers: ['1996', '1995', '1994', 'none of the above']

  }

];

​

function getRandomQuestion() {

  let currentRandomIndex;

  do {

    currentRandomIndex = Math.floor(Math.random() * quizArr.length);

  } while (currentRandomIndex === oldQuestionIndex);

  oldQuestionIndex = currentRandomIndex;

  return quizArr[currentRandomIndex].question;

}

​

function getRandomVariants(currentRandomIndex) {

  const answersIndicies = [];

  for (const value of quizArr[currentRandomIndex].answers) {

    let oldAnswersIndex = -1;

    do {

      oldAnswersIndex = Math.floor(Math.random() * quizArr[currentRandomIndex].answers.length);

    } while (answerIndicies.includes(oldAnswersIndex));

    answersIndicies.push(oldAnswersIndex);

  }

  return answersIndicies;

}

​

function showRandomQuestion() {

  const displayQuestQiz = getRandomQuestion();

  headerQuestion.innerHTML = displayQuestQiz;

}

​

btnSubmit.addEventListener('click', function() {

  showRandomQuestion();

});

showRandomQuestion();

​