quiz.js

// Web app's Firebase configuration
  var firebaseConfig = {
    apiKey: "AIzaSyAbFistmgFQcIOojLVD7cgXmTE9mLvuqVc",
    authDomain: "quizapp-74d37.firebaseapp.com",
    databaseURL: "https://quizapp-74d37.firebaseio.com",
    projectId: "quizapp-74d37",
    storageBucket: "quizapp-74d37.appspot.com",
    messagingSenderId: "10113678267",
    appId: "1:10113678267:web:d2aa73777b379fb241629e",
    measurementId: "G-PEKPZ347TY"
  };
  // Initialize Firebase
  firebase.initializeApp(firebaseConfig);
  var database = firebase.database();



  var getQuestion = document.getElementById("question");
  var getAnswer1 = document.getElementById("answer1");
  var getAnswer2 = document.getElementById("answer2");
  var getAnswer3 = document.getElementById("answer3");
  var getScore = document.getElementById("showScore");


  var quizQuestions;
  var questionId = 0;
  var score = 1;
  
// getting quiz data from Firebase
database.ref('QuizData').on('value', function(questions){
    quizQuestions = questions.val();
});


let getQuest = () => {
  //for (question in quizQuestions) {
    getQuestion.innerHTML = quizQuestions[questionId].question;
    getAnswer1.innerText = quizQuestions[questionId].answer1;
    getAnswer2.innerText = quizQuestions[questionId].answer2;
    getAnswer3.innerText = quizQuestions[questionId].answer3;
    getScore.innerText = score;
    if(quizQuestions[questionId].correctAnswer)
    {}
  //}
}

setInterval(getQuest, 1000);

//quizQuestions[1].correctAnswer;
questionId = questionId + 1;

// showing quiz data 
let nextQuestion = () => {
    questionId = questionId + 1;
    getQuestion.innerHTML = quizQuestions[questionId].question;
    getAnswer1.innerText = quizQuestions[questionId].answer1;
    getAnswer2.innerText = quizQuestions[questionId].answer2;
    getAnswer3.innerText = quizQuestions[questionId].answer3;
    console.log(quizQuestions[question].correctAnswer)
    questionId = questionId;
}