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General Discussion

Trevor Maltbie
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Trevor Maltbie
Full Stack JavaScript Techdegree Graduate 17,021 Points
Posted by Trevor Maltbie
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Trevor Maltbie
Full Stack JavaScript Techdegree Graduate 17,021 Points

Correct/Wrong Arrays Print As Undefined

Previewing this code gets everything right except the correct and incorrect arrays print as ":undefined" and "undefined" respectively.

I tried using template literals around buildList but that didn't fix anything. I also tried removing the initial declaration of the html variable as Dave did but again that did not fix anything. I'm at a loss. There must be a typo somewhere.

const quiz = [
  ['How many moons does Earth have?', 1],
  ['How many eyes does a spider have?', 8],
  ['How many states in USA?', 50]
];
let correct = 0;
let question;
let answer;
let response;
let correctArray = [];
let wrongArray = [];
let html;

function print(message) {
  const outputDiv = document.getElementById('output');
  outputDiv.innerHTML = message;
}

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

for(i=0; i<quiz.length; i++) {
  question = quiz[i][0];
  answer = quiz[i][1];
  response = parseInt(prompt(question));
  if (response === answer) {
    correct++;
    correctArray.push(question);
  } else {
    wrongArray.push(question);
  }
};

html = `You got ${correct} answers right.`;
html += '<h2>You got these questions correct:</h2>:';
html += buildList(correctArray);
html += '<h2>You got these questions incorrect:</h2>';
html += buildList(wrongArray);

console.log(correctArray); // this test was successful, console shows the correct questions. 
// still get undefined in the DOM though.
print(html);
Steven Parker
Steven Parker
231,184 Points
Steven Parker
Steven Parker
231,184 Points

I think you meant to post this in the "JavaScript" category. You can change it using "Edit Question", which is revealed by clicking on the small grey rectangle with the 3 dots in it.