Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Build a Quiz Challenge, Part 1 Solution

Ernie Smith
Ernie Smith
8,511 Points

Getting "undefined" printed to page. Please help.

I can't figure out why my quiz doesn't work. This is my code:

var questions = [ ["What is after zero?" , 1], ["What is after 1?" , 2], ["What is after 3?" , 3] ]; var correctAnswers = 0; var question; var answer; var response; var html;

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

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

hmtl = "You got " + correctAnswers + " correct answers!"; print(html);

Zack Jackson
Zack Jackson
30,215 Points

To post formatted code to the forum start it out with a line of three back ticks and close it with a line of three backticks.

your code here
var questions = [ ["What is after zero?" , 1], ["What is after 1?" , 2], ["What is after 3?" , 3] ]; 
var correctAnswers = 0; 
var question; 
var answer; 
var response; 
var html;

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

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

hmtl = "You got " + correctAnswers + " correct answers!"; 
print(html);

2 Answers

Ali .
Ali .
15,521 Points

Hi Ernie Smith,

You forgot to assign "i" for var. such as for (var i = 0; i < questions.length; i+=1).

Ernie Smith
Ernie Smith
8,511 Points

Thanks Ali, I can't believe I missed that after going through the code of and over again.

However, even by adding var i = 0 I still get "undefined" printed to the page.

Any other help would be much appreciated. Thank you!

Ernie Smith
Ernie Smith
8,511 Points

Doh! Nevermind, I just noticed I wrote "hmtl = " not html! Grrrrrr....