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JavaScript

Posted by Tayfun İlbakan
Tayfun İlbakan
6,977 Points

DevTools gives me error of "Uncaught TypeError: Cannot read property '0' of undefined at quiz.js:10"

I've checked everything with Guil's code but it seems perfectly similar to me, but when I execute it, after answering first question, it stops working and I'm having an error as "Uncaught TypeError: Cannot read property '0' of undefined at quiz.js:10"

Can you help me what is causing that?

https://w.trhou.se/4i60mkgj6e

const questions = [ ['Which year is it?', '2021'], ['What is your name?', 'Tayfun'] ['Whats your home country?', 'Turkey'] ];

let correctAnswers = 0;

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

if ( response === answer) { correctAnswers++; } }

let html = <h1>You got ${correctAnswers} question(s) correct</h1> ;

document.querySelector('main').innerHTML = html;

2 Answers

Jennifer Nordell
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STAFF
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Jennifer Nordell
Treehouse Teacher
Jennifer Nordell
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher

Hi there, Tayfun İlbakan ! You're doing great. The problem here is a single comma. Namely, you're missing a comma in your questions between the nested arrays so questions isn't really declared like it should be :smiley:

You have this:

const questions = [
  ['Which year is it?', '2021'], 
  ['What is your name?', 'Tayfun']
  ['Whats your home country?', 'Turkey']
];

But you need:

const questions = [
  ['Which year is it?', '2021'], 
  ['What is your name?', 'Tayfun'],  // there was a missing comma right here
  ['Whats your home country?', 'Turkey']
];

Hope this helps! :sparkles:

Tayfun İlbakan
Tayfun İlbakan
6,977 Points
Tayfun İlbakan
Tayfun İlbakan
6,977 Points

Oh, thanks a lot! I can't believe that I missed that! That solved my problem!