Lodash

_.defaults({ 'a': 1 }, { 'a': 3, 'b': 2 });
// → { 'a': 1, 'b': 2 }
_.partition([1, 2, 3, 4], n => n % 2);
// → [[1, 3], [2, 4]]

Download

Lodash is released under the MIT license & supports modern environments. Review the build differences & pick one that’s right for you.

Installation

In a browser:

<script src="lodash.js"></script>

Using npm:

$ npm i -g npm
$ npm i --save lodash

In Node.js:

// Load the full build.
var _ = require('lodash');
// Load the core build.
var _ = require('lodash/core');
// Load the FP build for immutable auto-curried iteratee-first data-last methods.
var fp = require('lodash/fp');
 
// Load method categories.
var array = require('lodash/array');
var object = require('lodash/fp/object');
 
// Cherry-pick methods for smaller browserify/rollup/webpack bundles.
var at = require('lodash/at');
var curryN = require('lodash/fp/curryN');

Note:
Install n_ for Lodash use in the Node.js < 6 REPL.

Why Lodash?

Lodash makes JavaScript easier by taking the hassle out of working with arrays, numbers, objects, strings, etc. Lodash’s modular methods are great for:

Iterating arrays, objects, & strings
Manipulating & testing values
Creating composite functions

Module Formats

Lodash is available in a variety of builds & module formats.

Complementary Tools

futil-js is a set of functional utilities designed to complement lodash

Support

Tested in Chrome 74-75, Firefox 66-67, IE 11, Edge 18, Safari 11-12, & Node.js 8-12.