---
title: Happy numbers
id: 594810f028c0303b75339ad1
challengeType: 5
videoUrl: ''
localeTitle: ''
---

## Description
undefined

## Instructions
undefined

## Tests
<section id='tests'>

```yml
tests:
  - text: ''
    testString: 'assert(typeof happy === "function", "<code>happy</code> is a function.");'
  - text: ''
    testString: 'assert(typeof happy(1) === "boolean", "<code>happy(1)</code> should return a boolean.");'
  - text: ''
    testString: 'assert(happy(1), "<code>happy(1)</code> should return true.");'
  - text: ''
    testString: 'assert(!happy(2), "<code>happy(2)</code> should return false.");'
  - text: ''
    testString: 'assert(happy(7), "<code>happy(7)</code> should return true.");'
  - text: ''
    testString: 'assert(happy(10), "<code>happy(10)</code> should return true.");'
  - text: ''
    testString: 'assert(happy(13), "<code>happy(13)</code> should return true.");'
  - text: ''
    testString: 'assert(happy(19), "<code>happy(19)</code> should return true.");'
  - text: ''
    testString: 'assert(happy(23), "<code>happy(23)</code> should return true.");'
  - text: ''
    testString: 'assert(happy(28), "<code>happy(28)</code> should return true.");'
  - text: ''
    testString: 'assert(happy(31), "<code>happy(31)</code> should return true.");'
  - text: ''
    testString: 'assert(happy(32), "<code>happy(32)</code> should return true:.");'
  - text: ''
    testString: 'assert(!happy(33), "<code>happy(33)</code> should return false.");'

```

</section>

## Challenge Seed
<section id='challengeSeed'>

<div id='js-seed'>

```js
function happy (number) {
  // Good luck!
}

```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```
</section>