arr-union

What is arr-union?

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.

What are arr-union's main functionalities?

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]

Other packages similar to arr-union

lodash.union

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.

README

arr-union

Combines a list of arrays, returning a single array with unique values, using strict equality for comparisons.

Install

Install with npm:

$ npm i arr-union --save

Benchmarks

This library is 10-20 times faster and more performant than array-union.

See the benchmarks.

#1: five-arrays
  array-union x 511,121 ops/sec ±0.80% (96 runs sampled)
  arr-union x 5,716,039 ops/sec ±0.86% (93 runs sampled)

#2: ten-arrays
  array-union x 245,196 ops/sec ±0.69% (94 runs sampled)
  arr-union x 1,850,786 ops/sec ±0.84% (97 runs sampled)

#3: two-arrays
  array-union x 563,869 ops/sec ±0.97% (94 runs sampled)
  arr-union x 9,602,852 ops/sec ±0.87% (92 runs sampled)

Usage

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']

Related projects

• arr-diff: Returns an array with only the unique values from the first array, by excluding all… more | homepage
• arr-filter: Faster alternative to javascript's native filter method. | homepage
• arr-flatten: Recursively flatten an array or arrays. This is the fastest implementation of array flatten. | homepage
• arr-map: Faster, node.js focused alternative to JavaScript's native array map. | homepage
• arr-pluck: Retrieves the value of a specified property from all elements in the collection. | homepage
• arr-reduce: Fast array reduce that also loops over sparse elements. | homepage
• array-unique: Return an array free of duplicate values. Fastest ES5 implementation. | homepage

Contributing

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.

Building docs

Generate readme and API documentation with verb:

$ npm i verb && npm run docs

Or, if verb is installed globally:

$ verb

Running tests

Install dev dependencies:

$ npm i -d && npm test

Author

Jon Schlinkert

• github/jonschlinkert
• twitter/jonschlinkert

License

Copyright © 2016 Jon Schlinkert Released under the MIT license.

This file was generated by verb, v0.9.0, on February 23, 2016.