Lodash Lodash Lodash A modern JavaScript utility library delivering modularity, performance & extras. Documentation FP Guide Version Support _ . defaults ({  'a' :  1  } ,  {  'a' :  3 ,   'b' :  2  }); // → { 'a': 1, 'b': 2 } _ . partition ([ 1 ,   2 ,   3 ,   4 ] ,  n  =>  n %  2 ); // → [[1, 3], [2, 4]] Download * Core build ( ~4kB gzipped ) * Full build ( ~24kB gzipped ) * CDN copies 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. * lodash & per method packages * lodash-es , babel-plugin-lodash , & lodash-webpack-plugin * lodash/fp * lodash-amd Complementary Tools * futil-js is a set of functional utilities designed to complement lodash Further Reading * Contributing * Release Notes * Wiki (Changelog, Roadmap, etc.) Support Tested in Node.js 4+, Bun 1.0+, and the latest Chromium, Firefox, WebKit, and Edge via Playwright, with a best-effort commitment to support Chrome 74+, Firefox 66+, IE 11, Edge 18, and Safari 11+. Site made with by @veksenn & @zthall . Maintained by the core team with help from our contributors .