# Check whether all values are equal

Compare every item with the first using Object.is.

Canonical: https://1loc.dev/validator/check-if-all-items-in-an-array-are-equal/
Version: 1.0.0
Runtime: JavaScript · Node.js 22 / modern browsers
Verification: Local fixtures; no external services
Updated: 2026-10-28

## Implementation

```javascript
function allEqual(values) { return values.every(value => Object.is(value, values[0])); }
```

## Input

```json
[
  7,
  7,
  7
]
```

## Expected output

```json
true
```

## Edge case

Input:
```json
[]
```
Output:
```json
true
```

## Limits

- The empty array returns true: no item violates the condition.
- Object.is distinguishes positive and negative zero. Objects use reference identity.

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/check-if-all-items-in-an-array-are-equal.mdx
Author: Nguyen Huu Phuoc and original contributors
Contributors: manu2504, glennfaison
Source commit: 14b481cf60dff1620ab1bb99a43b1f68068cdd9b
Copyright (c) 2020 phuoc-ng
License: MIT — https://1loc.dev/licenses/
Maintainer: Oveyon
Modifications: Curated implementation; explicit input bounds, edge cases, local fixtures and rebuilt presentation. Original MDX retained as inert source evidence.