# Compute the greatest common divisor between two numbers

Apply Euclid’s algorithm.

Canonical: https://1loc.dev/number/compute-the-greatest-common-divisor-between-two-numbers/
Version: 1.0.0
Runtime: JavaScript · Node.js 22 / modern browsers
Verification: Local fixtures; no external services
Updated: 2026-10-28

## Implementation

```javascript
function gcd({ a, b }) { return b === 0 ? Math.abs(a) : gcd({ a: b, b: a % b }); }
```

## Input

```json
{
  "a": 48,
  "b": 18
}
```

## Expected output

```json
6
```

## Edge case

Input:
```json
{
  "a": -4,
  "b": 6
}
```
Output:
```json
2
```

## Limits

- Returns a non-negative result; the original could return a negative divisor.
- Integers only.

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/compute-the-greatest-common-divisor-between-two-numbers.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: Returns a non-negative divisor; takes a and b as one object. Original MDX retained as inert source evidence.