---
id: 5ddb965c65d27e1512d44daa
title: Part 17
challengeType: 0
---
## Description
<section id='description'>
While you can use a loop to add everything in the `total` array to a variable, JavaScript provides the useful `reduce()` method.
Chain the `reduce()` method to the `Array.from()` expression.
</section>
## Instructions
<section id='instructions'>
</section>
## Tests
<section id='tests'>
```yml
tests:
- text: See description above for instructions.
testString: assert( code.replace(/\s/g, '').match(/Number\(meal\.value\)\)\.reduce\(\)/) );
```
</section>
## Challenge Seed
<section id='challengeSeed'>
<div id='html-seed'>
```html
<script>
document.getElementById('calorie-form').onsubmit = calculate;
function calculate(e) {
e.preventDefault();
const total = Array.from(
document.getElementsByClassName('cal-control')
).map(meal => Number(meal.value));
}
</script>
```
</div>
### Before Test
<div id='html-setup'>
```html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<meta name="description" content="" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<link rel="stylesheet" href="styles.css" />
</head>
<body>
<div class="container">
<form id="calorie-form">
<h2 class="center">Calorie Counter</h2>
<div class="grid">
<legend>Sex</legend>
<div>
<input type="radio" name="sex" id="female" value="F" checked />
<label for="female">
Female (2,000 calories)
</label>
<div>
<input type="radio" name="sex" id="male" value="M" />
<label for="male">
Male (2,500 calories)
</label>
</div>
</div>
</div>
<div class="grid" id="entries">
Breakfast
<input
type="number"
min="0"
class="cal-control"
id="breakfast"
/><br />
Lunch
<input type="number" min="0" class="cal-control" id="lunch" /><br />
Dinner <input type="number" min="0" class="cal-control" id="dinner" />
</div>
<button type="button" class="btn-add" id="add">
Add Entry
</button>
<button type="submit" class="btn-solid" id="calculate">
Calculate
</button>
<button type="button" class="btn-outline" id="clear">
Clear
</button>
</form>
<div id="output"></div>
</div>
</body>
</html>
```
</div>
### After Test
<div id='html-teardown'>
```html
</body>
</html>
```
</div>
</section>
## Solution
<section id='solution'>
```html
<script>
document.getElementById('calorie-form').onsubmit = calculate;
function calculate(e) {
e.preventDefault();
const total = Array.from(document.getElementsByClassName('cal-control'))
.map(meal => Number(meal.value))
.reduce();
}
</script>
```
</section>