| 1 | # arr-diff [](https://www.npmjs.com/package/arr-diff) [](https://npmjs.org/package/arr-diff) [](https://travis-ci.org/jonschlinkert/arr-diff)
|
|---|
| 2 |
|
|---|
| 3 | > Returns an array with only the unique values from the first array, by excluding all values from additional arrays using strict equality for comparisons.
|
|---|
| 4 |
|
|---|
| 5 | ## Install
|
|---|
| 6 |
|
|---|
| 7 | Install with [npm](https://www.npmjs.com/):
|
|---|
| 8 |
|
|---|
| 9 | ```sh
|
|---|
| 10 | $ npm install --save arr-diff
|
|---|
| 11 | ```
|
|---|
| 12 |
|
|---|
| 13 | Install with [yarn](https://yarnpkg.com):
|
|---|
| 14 |
|
|---|
| 15 | ```sh
|
|---|
| 16 | $ yarn add arr-diff
|
|---|
| 17 | ```
|
|---|
| 18 |
|
|---|
| 19 | Install with [bower](https://bower.io/)
|
|---|
| 20 |
|
|---|
| 21 | ```sh
|
|---|
| 22 | $ bower install arr-diff --save
|
|---|
| 23 | ```
|
|---|
| 24 |
|
|---|
| 25 | ## Usage
|
|---|
| 26 |
|
|---|
| 27 | Returns the difference between the first array and additional arrays.
|
|---|
| 28 |
|
|---|
| 29 | ```js
|
|---|
| 30 | var diff = require('arr-diff');
|
|---|
| 31 |
|
|---|
| 32 | var a = ['a', 'b', 'c', 'd'];
|
|---|
| 33 | var b = ['b', 'c'];
|
|---|
| 34 |
|
|---|
| 35 | console.log(diff(a, b))
|
|---|
| 36 | //=> ['a', 'd']
|
|---|
| 37 | ```
|
|---|
| 38 |
|
|---|
| 39 | ## Benchmarks
|
|---|
| 40 |
|
|---|
| 41 | This library versus [array-differ](https://github.com/sindresorhus/array-differ), on April 14, 2017:
|
|---|
| 42 |
|
|---|
| 43 | ```
|
|---|
| 44 | Benchmarking: (4 of 4)
|
|---|
| 45 | · long-dupes
|
|---|
| 46 | · long
|
|---|
| 47 | · med
|
|---|
| 48 | · short
|
|---|
| 49 |
|
|---|
| 50 | # benchmark/fixtures/long-dupes.js (100804 bytes)
|
|---|
| 51 | arr-diff-3.0.0 x 822 ops/sec ±0.67% (86 runs sampled)
|
|---|
| 52 | arr-diff-4.0.0 x 2,141 ops/sec ±0.42% (89 runs sampled)
|
|---|
| 53 | array-differ x 708 ops/sec ±0.70% (89 runs sampled)
|
|---|
| 54 |
|
|---|
| 55 | fastest is arr-diff-4.0.0
|
|---|
| 56 |
|
|---|
| 57 | # benchmark/fixtures/long.js (94529 bytes)
|
|---|
| 58 | arr-diff-3.0.0 x 882 ops/sec ±0.60% (87 runs sampled)
|
|---|
| 59 | arr-diff-4.0.0 x 2,329 ops/sec ±0.97% (83 runs sampled)
|
|---|
| 60 | array-differ x 769 ops/sec ±0.61% (90 runs sampled)
|
|---|
| 61 |
|
|---|
| 62 | fastest is arr-diff-4.0.0
|
|---|
| 63 |
|
|---|
| 64 | # benchmark/fixtures/med.js (708 bytes)
|
|---|
| 65 | arr-diff-3.0.0 x 856,150 ops/sec ±0.42% (89 runs sampled)
|
|---|
| 66 | arr-diff-4.0.0 x 4,665,249 ops/sec ±1.06% (89 runs sampled)
|
|---|
| 67 | array-differ x 653,888 ops/sec ±1.02% (86 runs sampled)
|
|---|
| 68 |
|
|---|
| 69 | fastest is arr-diff-4.0.0
|
|---|
| 70 |
|
|---|
| 71 | # benchmark/fixtures/short.js (60 bytes)
|
|---|
| 72 | arr-diff-3.0.0 x 3,078,467 ops/sec ±0.77% (93 runs sampled)
|
|---|
| 73 | arr-diff-4.0.0 x 9,213,296 ops/sec ±0.65% (89 runs sampled)
|
|---|
| 74 | array-differ x 1,337,051 ops/sec ±0.91% (92 runs sampled)
|
|---|
| 75 |
|
|---|
| 76 | fastest is arr-diff-4.0.0
|
|---|
| 77 | ```
|
|---|
| 78 |
|
|---|
| 79 | ## About
|
|---|
| 80 |
|
|---|
| 81 | ### Related projects
|
|---|
| 82 |
|
|---|
| 83 | * [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.")
|
|---|
| 84 | * [array-filter](https://www.npmjs.com/package/array-filter): Array#filter for older browsers. | [homepage](https://github.com/juliangruber/array-filter "Array#filter for older browsers.")
|
|---|
| 85 | * [array-intersection](https://www.npmjs.com/package/array-intersection): Return an array with the unique values present in _all_ given arrays using strict equality… [more](https://github.com/jonschlinkert/array-intersection) | [homepage](https://github.com/jonschlinkert/array-intersection "Return an array with the unique values present in _all_ given arrays using strict equality for comparisons.")
|
|---|
| 86 |
|
|---|
| 87 | ### Contributing
|
|---|
| 88 |
|
|---|
| 89 | Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new).
|
|---|
| 90 |
|
|---|
| 91 | ### Contributors
|
|---|
| 92 |
|
|---|
| 93 | | **Commits** | **Contributor** |
|
|---|
| 94 | | --- | --- |
|
|---|
| 95 | | 33 | [jonschlinkert](https://github.com/jonschlinkert) |
|
|---|
| 96 | | 2 | [paulmillr](https://github.com/paulmillr) |
|
|---|
| 97 |
|
|---|
| 98 | ### Building docs
|
|---|
| 99 |
|
|---|
| 100 | _(This project's readme.md is generated by [verb](https://github.com/verbose/verb-generate-readme), please don't edit the readme directly. Any changes to the readme must be made in the [.verb.md](.verb.md) readme template.)_
|
|---|
| 101 |
|
|---|
| 102 | To generate the readme, run the following command:
|
|---|
| 103 |
|
|---|
| 104 | ```sh
|
|---|
| 105 | $ npm install -g verbose/verb#dev verb-generate-readme && verb
|
|---|
| 106 | ```
|
|---|
| 107 |
|
|---|
| 108 | ### Running tests
|
|---|
| 109 |
|
|---|
| 110 | Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command:
|
|---|
| 111 |
|
|---|
| 112 | ```sh
|
|---|
| 113 | $ npm install && npm test
|
|---|
| 114 | ```
|
|---|
| 115 |
|
|---|
| 116 | ### Author
|
|---|
| 117 |
|
|---|
| 118 | **Jon Schlinkert**
|
|---|
| 119 |
|
|---|
| 120 | * [github/jonschlinkert](https://github.com/jonschlinkert)
|
|---|
| 121 | * [twitter/jonschlinkert](https://twitter.com/jonschlinkert)
|
|---|
| 122 |
|
|---|
| 123 | ### License
|
|---|
| 124 |
|
|---|
| 125 | Copyright © 2017, [Jon Schlinkert](https://github.com/jonschlinkert).
|
|---|
| 126 | Released under the [MIT License](LICENSE).
|
|---|
| 127 |
|
|---|
| 128 | ***
|
|---|
| 129 |
|
|---|
| 130 | _This file was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme), v0.5.0, on April 14, 2017._ |
|---|
