# array-unique [](https://www.npmjs.com/package/array-unique) [](https://npmjs.org/package/array-unique) [](https://travis-ci.org/jonschlinkert/array-unique)
Remove duplicate values from an array. Fastest ES5 implementation.
## Install
Install with [npm](https://www.npmjs.com/):
```sh
$ npm install --save array-unique
```
## Usage
```js
var unique = require('array-unique');
var arr = ['a', 'b', 'c', 'c'];
console.log(unique(arr)) //=> ['a', 'b', 'c']
console.log(arr) //=> ['a', 'b', 'c']
/* The above modifies the input array. To prevent that at a slight performance cost: */
var unique = require("array-unique").immutable;
var arr = ['a', 'b', 'c', 'c'];
console.log(unique(arr)) //=> ['a', 'b', 'c']
console.log(arr) //=> ['a', 'b', 'c', 'c']
```
## About
### Related projects
* [arr-diff](https://www.npmjs.com/package/arr-diff): Returns an array with only the unique values from the first array, by excluding all… [more](https://github.com/jonschlinkert/arr-diff) | [homepage](https://github.com/jonschlinkert/arr-diff "Returns an array with only the unique values from the first array, by excluding all values from additional arrays using strict equality for comparisons.")
* [arr-flatten](https://www.npmjs.com/package/arr-flatten): Recursively flatten an array or arrays. This is the fastest implementation of array flatten. | [homepage](https://github.com/jonschlinkert/arr-flatten "Recursively flatten an array or arrays. This is the fastest implementation of array flatten.")
* [arr-map](https://www.npmjs.com/package/arr-map): Faster, node.js focused alternative to JavaScript's native array map. | [homepage](https://github.com/jonschlinkert/arr-map "Faster, node.js focused alternative to JavaScript's native array map.")
* [arr-pluck](https://www.npmjs.com/package/arr-pluck): Retrieves the value of a specified property from all elements in the collection. | [homepage](https://github.com/jonschlinkert/arr-pluck "Retrieves the value of a specified property from all elements in the collection.")
* [arr-reduce](https://www.npmjs.com/package/arr-reduce): Fast array reduce that also loops over sparse elements. | [homepage](https://github.com/jonschlinkert/arr-reduce "Fast array reduce that also loops over sparse elements.")
* [arr-union](https://www.npmjs.com/package/arr-union): Combines a list of arrays, returning a single array with unique values, using strict equality… [more](https://github.com/jonschlinkert/arr-union) | [homepage](https://github.com/jonschlinkert/arr-union "Combines a list of arrays, returning a single array with unique values, using strict equality for comparisons.")
### Contributing
Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new).
### Building docs
_(This document was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme) (a [verb](https://github.com/verbose/verb) generator), please don't edit the readme directly. Any changes to the readme must be made in [.verb.md](.verb.md).)_
To generate the readme and API documentation with [verb](https://github.com/verbose/verb):
```sh
$ npm install -g verb verb-generate-readme && verb
```
### Running tests
Install dev dependencies:
```sh
$ npm install -d && npm test
```
### Author
**Jon Schlinkert**
* [github/jonschlinkert](https://github.com/jonschlinkert)
* [twitter/jonschlinkert](http://twitter.com/jonschlinkert)
### License
Copyright © 2016, [Jon Schlinkert](https://github.com/jonschlinkert).
Released under the [MIT license](https://github.com/jonschlinkert/array-unique/blob/master/LICENSE).
***
_This file was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme), v0.1.28, on July 31, 2016._