99 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			99 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
# arr-union [](https://www.npmjs.com/package/arr-union) [](https://travis-ci.org/jonschlinkert/arr-union)
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> Combines a list of arrays, returning a single array with unique values, using strict equality for comparisons.
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## Install
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Install with [npm](https://www.npmjs.com/):
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```sh
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$ npm i arr-union --save
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```
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## Benchmarks
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This library is **10-20 times faster** and more performant than [array-union](https://github.com/sindresorhus/array-union).
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See the [benchmarks](./benchmark).
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```sh
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#1: five-arrays
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  array-union x 511,121 ops/sec ±0.80% (96 runs sampled)
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  arr-union x 5,716,039 ops/sec ±0.86% (93 runs sampled)
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#2: ten-arrays
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  array-union x 245,196 ops/sec ±0.69% (94 runs sampled)
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  arr-union x 1,850,786 ops/sec ±0.84% (97 runs sampled)
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#3: two-arrays
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  array-union x 563,869 ops/sec ±0.97% (94 runs sampled)
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  arr-union x 9,602,852 ops/sec ±0.87% (92 runs sampled)
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```
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## Usage
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```js
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var union = require('arr-union');
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union(['a'], ['b', 'c'], ['d', 'e', 'f']);
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//=> ['a', 'b', 'c', 'd', 'e', 'f']
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```
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Returns only unique elements:
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```js
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union(['a', 'a'], ['b', 'c']);
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//=> ['a', 'b', 'c']
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```
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## Related projects
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* [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://www.npmjs.com/package/arr-diff) | [homepage](https://github.com/jonschlinkert/arr-diff)
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* [arr-filter](https://www.npmjs.com/package/arr-filter): Faster alternative to javascript's native filter method. | [homepage](https://github.com/jonschlinkert/arr-filter)
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* [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)
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* [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)
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* [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)
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* [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)
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* [array-unique](https://www.npmjs.com/package/array-unique): Return an array free of duplicate values. Fastest ES5 implementation. | [homepage](https://github.com/jonschlinkert/array-unique)
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## Contributing
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Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](https://github.com/jonschlinkert/arr-union/issues/new).
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## Building docs
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Generate readme and API documentation with [verb](https://github.com/verbose/verb):
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```sh
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$ npm i verb && npm run docs
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```
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Or, if [verb](https://github.com/verbose/verb) is installed globally:
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```sh
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$ verb
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```
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## Running tests
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Install dev dependencies:
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```sh
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$ npm i -d && npm test
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```
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## Author
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**Jon Schlinkert**
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* [github/jonschlinkert](https://github.com/jonschlinkert)
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* [twitter/jonschlinkert](http://twitter.com/jonschlinkert)
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## License
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Copyright © 2016 [Jon Schlinkert](https://github.com/jonschlinkert)
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Released under the [MIT license](https://github.com/jonschlinkert/arr-union/blob/master/LICENSE).
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***
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_This file was generated by [verb](https://github.com/verbose/verb), v0.9.0, on February 23, 2016._ |