arr-union
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Package description
The arr-union npm package is designed to create an array of unique values, in order, from the provided arrays. It is particularly useful for combining arrays while removing duplicate entries efficiently.
Union of multiple arrays
This feature allows you to pass multiple arrays to the union function, which returns a new array that includes every unique element from the input arrays, preserving the order they appear in the input.
const union = require('arr-union');
let result = union([1, 2], [2, 3], [3, 4]);
console.log(result); // Output: [1, 2, 3, 4]Lodash's union function offers similar functionality to arr-union. It creates an array of unique values, in order, from all given arrays using SameValueZero for equality comparisons. Compared to arr-union, lodash.union is part of a larger utility library, which might be preferable for projects that require additional utility functions beyond array union.
Underscore.js also provides a union function that computes the union of the passed-in arrays: the list of unique items, in order, that are present in one or more of the arrays. Like lodash, Underscore is a more comprehensive toolkit, which might be overkill if you only need the union functionality.
Readme
Combines a list of arrays, returning a single array with unique values, using strict equality for comparisons.
This library is 15-20 times faster and more performant (scales better) than array-union, which just uses [].concat.apply([], arguments).
See the benchmarks.
#1: five-arrays.js
array-union.js x 245,487 ops/sec ±0.99% (96 runs sampled)
current.js x 5,267,661 ops/sec ±0.63% (98 runs sampled)
#2: ten-arrays.js
array-union.js x 134,784 ops/sec ±0.51% (94 runs sampled)
current.js x 1,919,143 ops/sec ±0.45% (100 runs sampled)
#3: two-arrays.js
array-union.js x 308,374 ops/sec ±0.75% (96 runs sampled)
current.js x 7,361,915 ops/sec ±0.67% (95 runs sampled)
Install with npm
$ npm i arr-union --save
var union = require('arr-union');
union(['a'], ['b', 'c'], ['d', 'e', 'f']);
//=> ['a', 'b', 'c', 'd', 'e', 'f']
Returns only unique elements:
union(['a', 'a'], ['b', 'c']);
//=> ['a', 'b', 'c']
Install dev dependencies:
$ npm i -d && npm test
Pull requests and stars are always welcome. For bugs and feature requests, please create an issue
Jon Schlinkert
Copyright © 2015 Jon Schlinkert Released under the MIT license.
This file was generated by verb-cli on June 15, 2015.
FAQs
Combines a list of arrays, returning a single array with unique values, using strict equality for comparisons.
The npm package arr-union receives a total of 12,290,094 weekly downloads. As such, arr-union popularity was classified as popular.
We found that arr-union demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
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