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

Posted by Bla Blubb
Bla Blubb
2,740 Points

no pop up window shows up??

var questions = [
  ['How many states are in the United States?', 50],
  ['How many continents are there?', 7],
  ['How many legs does an insect have?', 6]
];
var correctAnswers = 0;
var question;
var answer;
var response;
var correct=[];
var wrong=[];

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




function buildList(arr){
  var listHtml="<ol>";
    for var i=0; i<arr.length; i+=1{
      listHtml+="<li>" + arr[i] +"</li>";
    }
    listHtml+="</ol>";
    return listHtml;      
}



for (var i = 0; i < questions.length; i += 1) {
  question = questions[i][0];
  answer = questions[i][1];
  response = prompt(question);
  response = parseInt(response);
  if (response === answer) {
    correctAnswers += 1;
    correct.push(question);
  } else{
    wrong.push(question);
  }
}

html = "You got " + correctAnswers + " question(s) right."
print(html);
html+="<h2> you got this questions correct:</h2>";
html+= buildList(correct);
jason phillips
jason phillips
18,131 Points

you have some issues with your buildList function. I am not sure what you are trying to accomplish in it, but you have an extra ":

 var listHtml=""; for var i=0; i"

also that is not the syntax for a for loop:

var i=0; i" + arr[i] +""; }

the loop should be something like this:

for(var i=0; i < arr.length; i++) {
//do stuff
}

1 Answer

Marcus Parsons
Marcus Parsons
15,719 Points

Hey Britta,

There were some issues with your code. As Jason pointed out, your for statement needed slightly redone. After the edit, you only needed parenthesis surrounding var i=0; i<arr.length; i+=1.

Also, you should not use the function print() because it is much slower than just calling document.write() itself and it causes issues with Safari because print() is a function for printing information from a page in Safari.

I also redid the bottom HTML and added a wrongAnswers variable, so that you can track wrong answers as well as right ones. 

var questions = [
  ['How many states are in the United States?', 50],
  ['How many continents are there?', 7],
  ['How many legs does an insect have?', 6]
];
var correctAnswers = 0, wrongAnswers = 0;
var question, answer, response;
var correct=[], wrong = [];

function buildList(arr){
  var listHtml="<ol>";
    for (var i=0; i<arr.length; i+=1){
      listHtml+="<li>" + arr[i] +"</li>";
    }
    listHtml+="</ol>";
    return listHtml;      
}

for (var i = 0; i < questions.length; i += 1) {
  question = questions[i][0];
  answer = questions[i][1];
  response = parseInt(prompt(question));
  if (response === answer) {
    correctAnswers += 1;
    correct.push(question);
  } else {
    wrongAnswers += 1;
    wrong.push(question);
  }
}

html = "<h2>You got " + correctAnswers + " question(s) right.</h2>";
html += "<p>You got these question(s) correct:</p>" + buildList(correct);
html += "<h2>You got " + wrongAnswers + " question(s) wrong.</h2>";
html += "<p>You got these question(s) wrong:</p>" + buildList(wrong);
document.write(html);