Javascript - Referring to a specific array element and comparing to a variable

Question

I am brand new to JavaScript and struggling with a quiz I am building. I am trying to compare the variable answer which is set by onclick with the correct answer which is an element in the rightAnswers array. There are 4 divs that I am using the set the variable and I've added them below.

All I want is the alert to fire so I know it's working so I can then continue adding to the function and behave as I want.

var qNumber = 1;
var questions = [, q1, q2, q3, q4, q5, q6, q7, q8, q9, q10, q11, q12, q13, q14, q15];
var rightAnswers = [, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3];
var answer = 0;

function setAnswer(choice) {
  answer = choice;
  checkAnswer();
}

function checkAnswer() {
  if (answer == rightAnswers[qNumber]) {
    alert("you got it right");
  }
}

<div class="answerA" onclick="setAnswer('1')">
  <div id="A">Answer 1 goes here</div>
</div>

<div class="answerB" onclick="setAnswer('2')">
  <div id="B">Answer 2 goes here</div>
</div>

<div class="answerC" onclick="setAnswer('3')">
  <div id="C">Answer 3 goes here</div>
</div>

<div class="answerD" onclick="setAnswer('4')">
  <div id="D">Answer 4 goes here</div>
</div>

It seems to be the checkAnswer function that is causing the issue and specifically when I add the reference to qNumber.

Any help would be greatly appreciated. Thank you.

I am doing that so I know which button is pressed - got the idea from another article here! Happy to do it another way if there's a better way of doing it! :) — Sam_987
– Sam_987, Commented Jun 11, 2020 at 10:23
@Sam_987: yes, but why a -string-? Why don’t you just use the plain numbers? — Cerbrus
– Cerbrus, Commented Jun 11, 2020 at 10:24
Also, the leading comma in your array declarations should be removed. — Cerbrus
– Cerbrus, Commented Jun 11, 2020 at 10:25
I would advice against such workarounds, as zero-indexing is very common, it's better to make sure you get comfortable with it. — Cerbrus
– Cerbrus, Commented Jun 11, 2020 at 10:33

user120242 · Accepted Answer · 2020-06-11 10:40:17Z

q1 is referring to a variable q1 that doesn't exist. If you want the string q1 you need to put it in quotes "q1". So line 2 var questions = ... is throwing an error, and the rest of it isn't finishing execution. You need to fix that line.

var qNumber = 1;
//var questions = [, q1, q2, q3, q4, q5, q6, q7, q8, q9, q10, q11, q12, q13, q14, q15];
var rightAnswers = [, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3];
var answer = 0;

function setAnswer(choice) {
  answer = choice;
  checkAnswer();
}

function checkAnswer() {
  if (answer == rightAnswers[qNumber]) {
    alert("you got it right");
  }
}

<div class="answerA" onclick="setAnswer('1')">
  <div id="A">Answer 1 goes here</div>
</div>

<div class="answerB" onclick="setAnswer('2')">
  <div id="B">Answer 2 goes here</div>
</div>

<div class="answerC" onclick="setAnswer('3')">
  <div id="C">Answer 3 goes here</div>
</div>

<div class="answerD" onclick="setAnswer('4')">
  <div id="D">Answer 4 goes here</div>
</div>

007 · Accepted Answer · 2020-06-11 10:42:12Z

0

var myQuestions = [
    {
        question: "What is 2+2?",
        answers: {
            a: '3',
            b: '5',
            c: '4'
        },
        correctAnswer: 'b'
    },
    {
        question: "What is blue?",
        answers: {
            a: 'dog',
            b: 'sky',
            c: 'chicken'
        },
        correctAnswer: 'a'
    }
];

You need some sort of better array and to do some sort of loop over it to generate the questions

answered Jun 11, 2020 at 10:42

007

236 bronze badges

1 Comment

ADyson Over a year ago

True but this doesn't directly answer the question posed, and doesn't provide a complete usable alternative. It's a bit of an incomplete answer, maybe more of a comment.

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