# Get all subsets of an array

Build the power set, smallest subsets first.

Canonical: https://1loc.dev/array/get-all-subsets-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 getSubsets(values) { return values.reduce((subsets, value) => subsets.concat(subsets.map(subset => [...subset, value])), [[]]); }
```

## Input

```json
[
  "a",
  "b",
  "c"
]
```

## Expected output

```json
[
  [],
  [
    "a"
  ],
  [
    "b"
  ],
  [
    "a",
    "b"
  ],
  [
    "c"
  ],
  [
    "a",
    "c"
  ],
  [
    "b",
    "c"
  ],
  [
    "a",
    "b",
    "c"
  ]
]
```

## Edge case

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

## Limits

- The result has 2^n subsets, so the lab accepts at most 10 values (1,024 subsets).

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-all-subsets-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: Caps input at 10 values before building 2^n subsets. Original MDX retained as inert source evidence.