Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

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

Frederick Bogdanoff
Frederick Bogdanoff
15,338 Points
Posted by Frederick Bogdanoff
Frederick Bogdanoff
15,338 Points

Appreciate some feed back on what i could've done better.

Hey guys.. This one took me a long time to understand and absorb what I was doing wrong.. However I'm still a bit unhappy: One thing I cant seem to get right is that the incorrect list returns an answer and not a question. Can someone please explain what I'm doing here?

var questions = [
  ["Who is the creator of Tesla?", "elon musk"],
  ["Whats the color of the sky?", "blue"],
  ["I love", "javascript"]
];

var correctAnswers = [];
var wrongAnswers = [];
var correctNums = 0;
var incorrectNums = 0;



function print (message) {
  document.write(message);
}

function printCorrect() {
 var cList = '<ol>';
  print("You answered " + correctNums + " questions correctly"); 
 cList += '<li>' + correctAnswers.join(' <li>') + '</li>' + '</ol>';
  document.write(cList);
}

function printWrong() {
  var wList = '<ol>';
  print("You answered " + incorrectNums + " questions incorrectly");
  wList += '<li>' + wrongAnswers.join(' <li>') + '</li>' + '</ol>';
  document.write(wList);
}



for (var i = 0; i < questions.length; i += 1) {
  var answer = prompt( questions[i][0] );
  answer = answer.toLowerCase();
  var correct = questions[i][1];


    if (correct === answer) {
    correctNums += 1;
    correctAnswers.push( questions[i][0] );
  } else {
    incorrectNums += 1;
    wrongAnswers.push( questions[i][0] );
  }
}


printCorrect();
printWrong();

1 Answer

Matt Brock
Matt Brock
28,330 Points

Hey Frederick, it's working for me. Both the correct list and incorrect list display the question, not the answer. Is it not working for you?

Frederick Bogdanoff
Frederick Bogdanoff
15,338 Points
Frederick Bogdanoff
Frederick Bogdanoff
15,338 Points

Woah... I must’ve been really tired yesterday.. my bad. Its working fine! Is there any other ways I could’ve gone about making the lists without functions?

Matt Brock
Matt Brock
28,330 Points

I think the way you wrote it works very well. Since both printCorrect() and printWrong() are quite similar I would suggest abstracting them to one single function, such as printList() and accept some arguments. A couple other little things I'd suggest:

  1. It's best to avoid creating functions that basically wrap a single existing function. You can cut the dedicated print() function and just use the native document.write() instead.
  2. You can use a variable question to simplify your for loop and make it a little easier to read!
  3. To increment a variable of type integer by 1, you can use the shorthand variable++;, which is the exact same thing as variable += 1;.

Here's what I mean:

var questions = [
  ["Who is the creator of Tesla?", "elon musk"],
  ["Whats the color of the sky?", "blue"],
  ["I love", "javascript"]
];

var correctAnswers = [];
var wrongAnswers = [];
var correctNums = 0;
var incorrectNums = 0;

// Combined function to keep code DRY!
function printList(nums, answers) {
  document.write("You answered " + nums + " questions incorrectly");
  var list = '<li>' + answers.join(' <li>') + '</li>';
  document.write('<ol>' + list + '</ol>');
}

for (var i = 0; i < questions.length; i++) {
  var question = questions[i][0];
  var answer = prompt( question );
  answer = answer.toLowerCase();
  var correct = questions[i][1];

  if (correct === answer) {
    correctNums++;
    correctAnswers.push( question );
  } else {
    incorrectNums++;
    wrongAnswers.push( question );
  }
}

printList(correctNums, correctAnswers);
printList(incorrectNums, wrongAnswers);
Matt Brock
Matt Brock
28,330 Points

Happy to help :)