# Get the average of an array

Divide the sum by the count.

Canonical: https://1loc.dev/array/get-the-average-of-an-array/
Version: 1.0.0
Runtime: JavaScript · Node.js 22 / modern browsers
Verification: Local fixtures; no external services
Updated: 2026-10-28

## Implementation

```javascript
function average(values) { return values.reduce((sum, value) => sum + value, 0) / values.length; }
```

## Input

```json
[
  4,
  8,
  3
]
```

## Expected output

```json
5
```

## Edge case

Input:
```json
[
  0.1,
  0.2
]
```
Output:
```json
0.15000000000000002
```

## Limits

- Floating-point sums are approximate, as the edge case shows.
- An empty array divides by zero and returns NaN (null in JSON); check the length first.

The lab validates types and size before calling this function. Add equivalent validation at your own trust boundary.

## Source and license

Original: https://github.com/phuocng/1loc/blob/14b481cf60dff1620ab1bb99a43b1f68068cdd9b/contents/get-the-average-of-an-array.mdx
Author: Nguyen Huu Phuoc and original contributors
Contributors: See original repository history
Source commit: 14b481cf60dff1620ab1bb99a43b1f68068cdd9b
Copyright (c) 2020 phuoc-ng
License: MIT — https://1loc.dev/licenses/
Maintainer: Oveyon
Modifications: Curated implementation; explicit input contract, edge case and limits. Original MDX retained as inert source evidence.