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# Improve the quiz - one solution

It keeps saying this: uncaught TypeError: incorrect.push is not a function at quiz.js:34:18 But that's exactly what the teacher did. I just don't understand why his works and mine doesn't?

```const questions = [
['What is the nearest planet towards the Sun?', 'Mercury'],
['What is the second nearest planet towards the sun?', 'Venus'],
['What is the third nearest planet towards the sun?', 'Earth'],
['Name of the planet next to planet Earth', 'Mars']

];

// 1. Create a multidimensional array to hold quiz questions and answers

// 2. Store the number of questions answered correctly
const correct = 0;
const incorrect = 0;
let correctAnswers = 0;

/*
3. Use a loop to cycle through each question
- Present each question to the user
- Compare the user's response to answer in the array
- If the response matches the answer, the number of correctly
answered questions increments by 1
*/
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++;
correct.push(questions);
} else {
incorrect.push(questions);
}
}

function createListItems( arr ) {
let items = '';
for ( let i = 0; i < arr.length; i++ ) {
items += `<li>\${ arr[i] [0] }, by \${ arr[i][1] } - \${ arr[i][2] }</li>`;
}
return items;
}

// 4. Display the number of correct answers to the user

let html = `
<h1>You got \${correctAnswers} question(s) correct</h1>
<h2>You got these questions right:</h2>
<ol>\${ createListItems(correct) }</ol>

<h2>You got these questions wrong:</h2>
<ol>\${ createListItems(incorrect) }</ol>
`;

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

## 1 Answer

The push method only exists on arrays, and in the video the variable `incorrect` is created as an array:

```const incorrect = [];
```

But in this code, it is created as number:

```const incorrect = 0;
```