# Lo-Dash v2.4.1
A utility library delivering consistency, [customization](http://lodash.com/custom-builds), [performance](http://lodash.com/benchmarks), & [extras](http://lodash.com/#features).
## Download
Check out our [wiki]([https://github.com/lodash/lodash/wiki/build-differences]) for details over the differences between builds.
* Modern builds perfect for newer browsers/environments:
[Development](https://raw.github.com/lodash/lodash/2.4.1/dist/lodash.js) &
[Production](https://raw.github.com/lodash/lodash/2.4.1/dist/lodash.min.js)
* Compatibility builds for older environment support too:
[Development](https://raw.github.com/lodash/lodash/2.4.1/dist/lodash.compat.js) &
[Production](https://raw.github.com/lodash/lodash/2.4.1/dist/lodash.compat.min.js)
* Underscore builds to use as a drop-in replacement:
[Development](https://raw.github.com/lodash/lodash/2.4.1/dist/lodash.underscore.js) &
[Production](https://raw.github.com/lodash/lodash/2.4.1/dist/lodash.underscore.min.js)
CDN copies are available on [cdnjs](http://cdnjs.com/libraries/lodash.js/) & [jsDelivr](http://www.jsdelivr.com/#!lodash). For smaller file sizes, create [custom builds](http://lodash.com/custom-builds) with only the features needed.
Love modules? We’ve got you covered with [lodash-amd](https://npmjs.org/package/lodash-amd), [lodash-es6](https://github.com/lodash/lodash-es6), [lodash-node](https://npmjs.org/package/lodash-node), & [npm packages](https://npmjs.org/browse/keyword/lodash-modularized) per method.
## Dive in
There’s plenty of **[documentation](http://lodash.com/docs)**, [unit tests](http://lodash.com/tests), & [benchmarks](http://lodash.com/benchmarks).
Check out DevDocs as a fast, organized, & searchable interface for our documentation.
The full changelog for this release is available on our [wiki](https://github.com/lodash/lodash/wiki/Changelog).
A list of upcoming features is available on our [roadmap](https://github.com/lodash/lodash/wiki/Roadmap).
## Features *not* in Underscore
* AMD loader support ([curl](https://github.com/cujojs/curl), [dojo](http://dojotoolkit.org/), [requirejs](http://requirejs.org/), etc.)
* [_(…)](http://lodash.com/docs#_) supports intuitive chaining
* [_.at](http://lodash.com/docs#at) for cherry-picking collection values
* [_.bindKey](http://lodash.com/docs#bindKey) for binding [*“lazy”*](http://michaux.ca/articles/lazy-function-definition-pattern) defined methods
* [_.clone](http://lodash.com/docs#clone) supports shallow cloning of `Date` & `RegExp` objects
* [_.cloneDeep](http://lodash.com/docs#cloneDeep) for deep cloning arrays & objects
* [_.constant](http://lodash.com/docs#constant) & [_.property](http://lodash.com/docs#property) function generators for composing functions
* [_.contains](http://lodash.com/docs#contains) accepts a `fromIndex`
* [_.create](http://lodash.com/docs#create) for easier object inheritance
* [_.createCallback](http://lodash.com/docs#createCallback) for extending callbacks in methods & mixins
* [_.curry](http://lodash.com/docs#curry) for creating [curried](http://hughfdjackson.com/javascript/2013/07/06/why-curry-helps/) functions
* [_.debounce](http://lodash.com/docs#debounce) & [_.throttle](http://lodash.com/docs#throttle) accept additional `options` for more control
* [_.findIndex](http://lodash.com/docs#findIndex) & [_.findKey](http://lodash.com/docs#findKey) for finding indexes & keys
* [_.forEach](http://lodash.com/docs#forEach) is chainable & supports exiting early
* [_.forIn](http://lodash.com/docs#forIn) for iterating own & inherited properties
* [_.forOwn](http://lodash.com/docs#forOwn) for iterating own properties
* [_.isPlainObject](http://lodash.com/docs#isPlainObject) for checking if values are created by `Object`
* [_.mapValues](http://lodash.com/docs#mapValues) for [mapping](http://lodash.com/docs#map) values to an object
* [_.memoize](http://lodash.com/docs#memoize) exposes the `cache` of memoized functions
* [_.merge](http://lodash.com/docs#merge) for a deep [_.extend](http://lodash.com/docs#extend)
* [_.noop](http://lodash.com/docs#noop) for function placeholders
* [_.now](http://lodash.com/docs#now) as a cross-browser `Date.now` alternative
* [_.parseInt](http://lodash.com/docs#parseInt) for consistent behavior
* [_.pull](http://lodash.com/docs#pull) & [_.remove](http://lodash.com/docs#remove) for mutating arrays
* [_.random](http://lodash.com/docs#random) supports returning floating-point numbers
* [_.runInContext](http://lodash.com/docs#runInContext) for easier mocking
* [_.sortBy](http://lodash.com/docs#sortBy) supports sorting by multiple properties
* [_.support](http://lodash.com/docs#support) for flagging environment features
* [_.template](http://lodash.com/docs#template) supports [*“imports”*](http://lodash.com/docs#templateSettings_imports) options & [ES6 template delimiters](http://people.mozilla.org/~jorendorff/es6-draft.html#sec-literals-string-literals)
* [_.transform](http://lodash.com/docs#transform) as a powerful alternative to [_.reduce](http://lodash.com/docs#reduce) for transforming objects
* [_.where](http://lodash.com/docs#where) supports deep object comparisons
* [_.xor](http://lodash.com/docs#xor) as a companion to [_.difference](http://lodash.com/docs#difference), [_.intersection](http://lodash.com/docs#intersection), & [_.union](http://lodash.com/docs#union)
* [_.zip](http://lodash.com/docs#zip) is capable of unzipping values
* [_.omit](http://lodash.com/docs#omit), [_.pick](http://lodash.com/docs#pick), &
[more](http://lodash.com/docs "_.assign, _.clone, _.cloneDeep, _.first, _.initial, _.isEqual, _.last, _.merge, _.rest") accept callbacks
* [_.contains](http://lodash.com/docs#contains), [_.toArray](http://lodash.com/docs#toArray), &
[more](http://lodash.com/docs "_.at, _.countBy, _.every, _.filter, _.find, _.forEach, _.forEachRight, _.groupBy, _.invoke, _.map, _.max, _.min, _.pluck, _.reduce, _.reduceRight, _.reject, _.shuffle, _.size, _.some, _.sortBy, _.where") accept strings
* [_.filter](http://lodash.com/docs#filter), [_.map](http://lodash.com/docs#map), &
[more](http://lodash.com/docs "_.countBy, _.every, _.find, _.findKey, _.findLast, _.findLastIndex, _.findLastKey, _.first, _.groupBy, _.initial, _.last, _.max, _.min, _.reject, _.rest, _.some, _.sortBy, _.sortedIndex, _.uniq") support *“_.pluck”* & *“_.where”* shorthands
* [_.findLast](http://lodash.com/docs#findLast), [_.findLastIndex](http://lodash.com/docs#findLastIndex), &
[more](http://lodash.com/docs "_.findLastKey, _.forEachRight, _.forInRight, _.forOwnRight, _.partialRight") right-associative methods
## Resources
* Podcasts
- [JavaScript Jabber](http://javascriptjabber.com/079-jsj-lo-dash-with-john-david-dalton/)
* Posts
- [Say “Hello” to Lo-Dash](http://kitcambridge.be/blog/say-hello-to-lo-dash/)
- [Custom builds in Lo-Dash 2.0](http://kitcambridge.be/blog/custom-builds-in-lo-dash-2-dot-0/)
* Videos
- [Introduction](https://vimeo.com/44154599)
- [Origins](https://vimeo.com/44154600)
- [Optimizations & builds](https://vimeo.com/44154601)
- [Native method use](https://vimeo.com/48576012)
- [Testing](https://vimeo.com/45865290)
- [CascadiaJS ’12](http://www.youtube.com/watch?v=dpPy4f_SeEk)
A list of other community created podcasts, posts, & videos is available on our [wiki](https://github.com/lodash/lodash/wiki/Resources).
## Support
Tested in Chrome 5~31, Firefox 2~25, IE 6-11, Opera 9.25~17, Safari 3-7, Node.js 0.6.21~0.10.22, Narwhal 0.3.2, PhantomJS 1.9.2, RingoJS 0.9, & Rhino 1.7RC5.
Automated browser test results [are available](https://saucelabs.com/u/lodash) as well as [Travis CI](https://travis-ci.org/) builds for [lodash](https://travis-ci.org/lodash/lodash/), [lodash-cli](https://travis-ci.org/lodash/lodash-cli/), [lodash-amd](https://travis-ci.org/lodash/lodash-amd/), [lodash-node](https://travis-ci.org/lodash/lodash-node/), & [grunt-lodash](https://travis-ci.org/lodash/grunt-lodash).
Special thanks to [Sauce Labs](https://saucelabs.com/) for providing automated browser testing.
[](https://saucelabs.com/ "Sauce Labs: Selenium Testing & More")
## Installation & usage
In browsers:
```html
```
Using [`npm`](http://npmjs.org/):
```bash
npm i --save lodash
{sudo} npm i -g lodash
npm ln lodash
```
In [Node.js](http://nodejs.org/) & [Ringo](http://ringojs.org/):
```js
var _ = require('lodash');
// or as Underscore
var _ = require('lodash/dist/lodash.underscore');
```
**Notes:**
* Don’t assign values to [special variable](http://nodejs.org/api/repl.html#repl_repl_features) `_` when in the REPL
* If Lo-Dash is installed globally, run [`npm ln lodash`](http://blog.nodejs.org/2011/03/23/npm-1-0-global-vs-local-installation/) in your project’s root directory *before* requiring it
In [Rhino](http://www.mozilla.org/rhino/):
```js
load('lodash.js');
```
In an AMD loader:
```js
require({
'packages': [
{ 'name': 'lodash', 'location': 'path/to/lodash', 'main': 'lodash' }
]
},
['lodash'], function(_) {
console.log(_.VERSION);
});
```
## Author
| [](https://twitter.com/jdalton "Follow @jdalton on Twitter") |
|---|
| [John-David Dalton](http://allyoucanleet.com/) |
## Contributors
| [](https://twitter.com/blainebublitz "Follow @BlaineBublitz on Twitter") | [](https://twitter.com/kitcambridge "Follow @kitcambridge on Twitter") | [](https://twitter.com/mathias "Follow @mathias on Twitter") |
|---|---|---|
| [Blaine Bublitz](http://www.iceddev.com/) | [Kit Cambridge](http://kitcambridge.be/) | [Mathias Bynens](http://mathiasbynens.be/) |
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