Lo-Dash v2.0.0

A utility library delivering consistency, customization, performance, & extras.

Download

• Modern builds: Development & Production

• Compatibility builds: Development & Production

• Underscore builds: Development & Production

Love modules? We’ve got you covered with lodash-amd, lodash-node, and npm packages per method.

CDN copies are available on cdnjs & jsDelivr.
For smaller file sizes, create custom builds with only the features needed.

Dive in

There’s plenty of documentation, unit tests, & benchmarks.

For a list of upcoming features, check out our roadmap.

Features not in Underscore

• AMD loader support (curl, dojo, requirejs, etc.)
• _(…) supports intuitive chaining
• _.at for cherry-picking collection values
• _.bindKey for binding “lazy” defined methods
• _.cloneDeep for deep cloning arrays & objects
• _.contains accepts a fromIndex
• _.createCallback for extending callbacks in methods & mixins
• _.curry for creating curried functions
• _.debounce & _.throttle accept options for more control
• _.findIndex & _.findKey for finding indexes & keys
• _.forEach is chainable & supports exiting early
• _.forIn for iterating own & inherited properties
• _.forOwn for iterating own properties
• _.isPlainObject for checking if values are created by Object
• _.memoize exposes the cache of memoized functions
• _.merge for a deep _.extend
• _.parseInt for consistent behavior
• _.partialRight for partial application from the right
• _.pull & _.remove for mutating arrays
• _.runInContext for easier mocking
• _.support for flagging environment features
• _.template supports “imports” options & ES6 template delimiters
• _.transform as a powerful alternative to _.reduce for transforming objects
• _.where supports deep object comparisons
• _.zip is capable of unzipping values
• _.omit, _.pick, & more accept callbacks
• _.contains, _.toArray, & more accept strings
• _.filter, _.map, & more support “_.pluck” & “_.where” shorthands
• _.findLast, _.findLastIndex, & more right-associative methods

Resources

• Posts

• Say “Hello” to Lo-Dash
• Custom builds in Lo-Dash 2.0

• Videos

• Introduction
• Origins
• Optimizations & builds
• Native method use
• Testing
• CascadiaJS ’12

Support

Tested in Chrome 529, Firefox 223, IE 6-10, Opera 9.25~15, Safari 3-6, Node.js 0.6.8-0.10.18, Narwhal 0.3.2, PhantomJS 1.9.1, RingoJS 0.9, & Rhino 1.7RC5.

Installation & usage

In browsers:

<script src="lodash.js"></script>

Using npm:

npm i lodash

{sudo} npm i -g lodash
npm link lodash

In Node.js & Ringo:

var _ = require('lodash');
// or as Underscore
var _ = require('lodash/dist/lodash.underscore');

Notes:

• Don’t assign values to special variable _ when in the REPL
• If Lo-Dash is installed globally, run npm link lodash in your project’s root directory before requiring it
• Node.js 0.10.8-0.10.11 have bugs preventing minified builds

In Rhino:

load('lodash.js');

In an AMD loader:

require({
  'packages': [
    { 'name': 'lodash', 'location': 'path/to/lodash', 'main': 'lodash' }
  ]
},
['lodash'], function(_) {
  console.log(_.VERSION);
});

Release Notes

^v2.0.0

Compatibility Warnings

• Aligned _.after with Underscore 1.5.0, making it always return a function

Noteable Changes

• Created Lo-Dash methods as npm packages & AMD/Node.js modules
• Made _.chain force chaining for all methods, even those that normally return unwrapped values
• Moved the build utility to lodash-cli
• Optimized _.contains, _.debounce, _.isArguments, _.throttle, _.where,
  & functions created by _.bind, _.bindKey, _.curry, _.partial, & _.partialRight
• Added _.curry, _.forEachRight, _.indexBy, _.findLast, _.findLastIndex,
  _.findLastKey, _.forInRight, _.forOwnRight, _.pull, _.remove, & _.sample

Other Changes

• Added Curl & Dojo module loaders to the unit tests
• Added the modularize build option
• Added support for the iife command to be used without an %output% token
• Added support for _.mixin to accept a destination object
• Added support for _.range to accept a step of 0
• Added _.eachRight as an alias for _.forEachRight
• Ensured “Arrays” methods support arguments objects
• Ensured “Functions” methods throw when not passed functions
• Ensured _.at works as a callback for _.map
• Ensured _.createCallback works when no argCount is specified
• Ensured _.first & _.last return arrays when passed a falsey array with an n value
• Ensured _.flatten works with arguments objects
• Ensured minified files work with Dojo’s builder
• Ensured _.zipObject skips falsey elements
• Improved dead code removal from builds
• Improved JSDoc syntax
• Made _.memoize avoid prefixing cache keys when using a resolver function
• Made _.unzip an alias of _.zip
• Removed local clearTimeout & setTimeout variables from the underscore build
• Reduced the size of the repo & npm package
• Simplified the bailout in createCache
• Updated sourceURL & sourceMappingURL syntax
• Updated underscore build compatibility to v1.5.2

The full changelog is available here.

BestieJS

Lo-Dash is part of the BestieJS “Best in Class” module collection. This means it promotes solid environment support, ES5+ precedents, unit testing, & plenty of documentation.

Author

John-David Dalton

Contributors

Blaine Bublitz	Kit Cambridge	Mathias Bynens