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JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Build a Quiz Challenge, Part 2 Solution

Posted by Taylor Fritz
Taylor Fritz
13,265 Points

Getting "undefined" list items where there should be nothing listed..

My code is running correctly EXCEPT it will create three list items under both the correct/incorrect sections and name then "undefined".. Any ideas on what I have incorrect here? I know it is messier than he explained, I wanted to take a shot at things before I saw his solution.

let quiz = [ 
  [`What is my first name?`, 1],
  [`What is my husband's name?`, 2],
  [`Is it faster to Beijing or by bus?`, 3]
];

let correctQ = [];
let incorrectQ = [];

let correctAnswers = 0;
let question;
let answer;
let response;
let html;


function print(message) {
  let outputDiv = document.getElementById("output");
  outputDiv.innerHTML = message;
}

function buildList(arr) {
  let listHTML = "<ol>";
  for (i=0;i<quiz.length;i++) {
    listHTML += "<li>" + arr[i] + "</li>"
  }
  listHTML += "</ol>"
  return listHTML;
}


for (i=0;i<quiz.length;i++) {
  question = quiz[i][0];
  answer = quiz[i][1]
  response = Number(prompt(question));
  if (response === answer ){
    correctAnswers += 1;
    correctQ.push(question);
  } else {
    incorrectQ.push(question);
  }
}

html = "You got " + correctAnswers + " question(s) correct!";
print(html);

html += `<h2>You answered these questions correctly:</h2>`
html += buildList(correctQ);
html += `<h2>You answered these questions incorrectly:</h2>`
html += buildList(incorrectQ);
print(html);