A drop-in replacement^{[*](https://github.com/bestiejs/lodash/wiki/Drop-in-Disclaimer)} for Underscore.js, from the devs behind[jsPerf.com](http://jsperf.com), delivering[performance](http://lodash.com/benchmarks),[bug fixes](https://github.com/bestiejs/lodash#resolved-underscorejs-issues-20), and[additional features](https://github.com/bestiejs/lodash#features).

A drop-in replacement^{[*](https://github.com/bestiejs/lodash/wiki/Drop-in-Disclaimer)} for Underscore.js, from the devs behind[jsPerf.com](http://jsperf.com), delivering[performance](http://lodash.com/benchmarks),[bug fixes](https://github.com/bestiejs/lodash#resolved-underscorejs-issues-30), and[additional features](https://github.com/bestiejs/lodash#features).

Lo-Dash’s performance is gained by avoiding slower native methods, instead opting for simplified non-ES5 compliant methods optimized for common usage, and by leveraging function compilation to reduce the number of overall function calls.

*[Development source](https://raw.github.com/bestiejs/lodash/v0.5.1/lodash.js)

*[Production source](https://raw.github.com/bestiejs/lodash/v0.5.1/lodash.min.js)

*[Development source](https://raw.github.com/bestiejs/lodash/v0.5.2/lodash.js)

*[Production source](https://raw.github.com/bestiejs/lodash/v0.5.2/lodash.min.js)

* CDN copies of ≤[v0.5.1](http://cdnjs.cloudflare.com/ajax/libs/lodash.js/0.5.1/lodash.min.js) are available on[cdnjs](http://cdnjs.com/) thanks to[CloudFlare](http://www.cloudflare.com/)

* For optimal performance,[create a custom build](https://github.com/bestiejs/lodash#custom-builds) with only the features you need

* AMD loader support ([RequireJS](http://requirejs.org/),[curl.js](https://github.com/cujojs/curl), etc.)

*[_.bind](http://lodash.com/docs#bind) supports*"lazy"* binding

*[_.clone](http://lodash.com/docs#clone) supports*"deep"* cloning

*[_.bind](http://lodash.com/docs#bind) supports*“lazy”* binding

*[_.clone](http://lodash.com/docs#clone) supports*“deep”* cloning

*[_.countBy](http://lodash.com/docs#countBy) as a compainion function for[_.groupBy](http://lodash.com/docs#groupBy) and[_.sortBy](http://lodash.com/docs#sortBy)

*[_.debounce](http://lodash.com/docs#debounce)’ed functions match[_.throttle](http://lodash.com/docs#throttle)’ed functions’ return value behavior

*[_.drop](http://lodash.com/docs#drop) for the inverse functionality of[_.pick](http://lodash.com/docs#pick)

*[_.forOwn](http://lodash.com/docs#forOwn) for iterating over an object’s own properties

*[_.groupBy](http://lodash.com/docs#groupBy),[_.sortedIndex](http://lodash.com/docs#sortedIndex), and[_.uniq](http://lodash.com/docs#uniq) accept a`thisArg` argument

*[_.indexOf](http://lodash.com/docs#indexOf) and[_.lastIndexOf](http://lodash.com/docs#lastIndexOf) accept a`fromIndex` argument

*[_.merge](http://lodash.com/docs#merge) for a*"deep"*[_.extend](http://lodash.com/docs#extend)

*[_.merge](http://lodash.com/docs#merge) for a*“deep”*[_.extend](http://lodash.com/docs#extend)

*[_.partial](http://lodash.com/docs#partial) for partial application without`this` binding

*[_.sortBy](http://lodash.com/docs#sortBy) performs a[stable](http://en.wikipedia.org/wiki/Sorting_algorithm#Stability) sort

*[_.template](http://lodash.com/docs#template) utilizes[sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl) for easier debugging

Custom builds may be created in three ways:

1. Use the`category` argument to pass the categories of methods to include in the build.<br>

Valid categories are*"arrays"*,*"chaining"*,*"collections"*,*"functions"*,*"objects"*, and*"utilities"*.

Valid categories are*“arrays”*,*“chaining”*,*“collections”*,*“functions”*,*“objects”*, and*“utilities”*.

lodash category=collections,functions

lodash category="collections, functions"

});

* Allow iteration of objects with a`length` property[[#148](https://github.com/documentcloud/underscore/issues/148),[#154](https://github.com/documentcloud/underscore/issues/154),[#252](https://github.com/documentcloud/underscore/issues/252),[#448](https://github.com/documentcloud/underscore/issues/448),[#659](https://github.com/documentcloud/underscore/issues/659),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L552-558)]

* Ensure array-like objects with invalid`length` properties are treated like regular objects[[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L499-509)]

* Ensure*"Arrays"*methods allow falsey`array`arguments[[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L1495-1533)]

* Ensure*"Collections"* methods allow string`collection` arguments[[#247](https://github.com/documentcloud/underscore/issues/247),[#276](https://github.com/documentcloud/underscore/issues/276),[#561](https://github.com/documentcloud/underscore/pull/561),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L511-529)]

* Ensure templates compiled with errors are inspectable[[#666](https://github.com/documentcloud/underscore/issues/666),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L1240-1243)]

* Fix cross-browser object iteration bugs[[#60](https://github.com/documentcloud/underscore/issues/60),[#376](https://github.com/documentcloud/underscore/issues/376),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L563-588)]

* Allow iteration of objects with a`length` property[[#148](https://github.com/documentcloud/underscore/issues/148),[#154](https://github.com/documentcloud/underscore/issues/154),[#252](https://github.com/documentcloud/underscore/issues/252),[#448](https://github.com/documentcloud/underscore/issues/448),[#659](https://github.com/documentcloud/underscore/issues/659),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L551-557)]

* Ensure array-like objects with invalid`length` properties are treated like regular objects[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L499-509)]

* Ensure*“Arrays”*, “Collections”, and “Objects”methods allow falsey arguments[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L1558-1593)]

* Ensure*“Collections”* methods allow string`collection` arguments[[#247](https://github.com/documentcloud/underscore/issues/247),[#276](https://github.com/documentcloud/underscore/issues/276),[#561](https://github.com/documentcloud/underscore/pull/561),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L511-529)]

* Ensure templates compiled with errors are inspectable[[#666](https://github.com/documentcloud/underscore/issues/666),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L1299-1302)]

* Fix cross-browser object iteration bugs[[#60](https://github.com/documentcloud/underscore/issues/60),[#376](https://github.com/documentcloud/underscore/issues/376),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L562-587)]

* Handle arrays with`undefined` values correctly in IE < 9[[#601](https://github.com/documentcloud/underscore/issues/601)]

* Methods should work on pages with incorrectly shimmed native methods[[#7](https://github.com/documentcloud/underscore/issues/7),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L117-123)]

* Register as an AMD module, but still export to global[[#431](https://github.com/documentcloud/underscore/pull/431),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L101-115)]

*`_(…)` should return passed wrapper instances[[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L135-138)]

*`_.clone` should allow`deep` cloning[[#595](https://github.com/documentcloud/underscore/pull/595),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L205-220)]

*`_.contains` should work with strings[[#667](https://github.com/documentcloud/underscore/pull/667),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L275-284)]

*`_.escape` should return an empty string when passed`null` or`undefined`[[#427](https://github.com/documentcloud/underscore/issues/427),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L375-378)]

*`_.extend` should recursively extend objects[[#379](https://github.com/documentcloud/underscore/pull/379),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L892-914)]

*`_.forEach` should be chainable[[#142](https://github.com/documentcloud/underscore/issues/142),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L494-497)]

*`_.forEach` should allow exiting iteration early[[#211](https://github.com/documentcloud/underscore/issues/211),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L590-609)]

*`_.groupBy` should add values to own, not inherited, properties[[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L624-631)]

*`_.isEmpty` and`_.size` should support jQuery/MooTools DOM query collections[[#690](https://github.com/documentcloud/underscore/pull/690),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L724-729)]

*`_.isEqual` should return`true` for like-objects from different documents[[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L765-785)]

*`_.isObject` should avoid V8 bug[#2291](http://code.google.com/p/v8/issues/detail?id=2291)[[#605](https://github.com/documentcloud/underscore/issues/605),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L793-805)]

*`_.isNaN(new Number(NaN))` should return`true`[[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L813-815)]

*`_.keys` and`_.size` should work with`arguments` objects cross-browser[[#396](https://github.com/documentcloud/underscore/issues/396),[#653](https://github.com/documentcloud/underscore/issues/653),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L825-827)]

* Methods should work on pages with incorrectly shimmed native methods[[#7](https://github.com/documentcloud/underscore/issues/7),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L117-123)]

* Register as an AMD module, but still export to global[[#431](https://github.com/documentcloud/underscore/pull/431),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L101-115)]

*`_(…)` should return passed wrapper instances[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L135-138)]

*`_.clone` should allow`deep` cloning[[#595](https://github.com/documentcloud/underscore/pull/595),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L205-220)]

*`_.contains` should work with strings[[#667](https://github.com/documentcloud/underscore/pull/667),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L275-284)]

*`_.escape` should return an empty string when passed`null` or`undefined`[[#427](https://github.com/documentcloud/underscore/issues/427),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L375-378)]

*`_.extend` should recursively extend objects[[#379](https://github.com/documentcloud/underscore/pull/379),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L952-974)]

*`_.forEach` should be chainable[[#142](https://github.com/documentcloud/underscore/issues/142),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L494-497)]

*`_.forEach` should allow exiting iteration early[[#211](https://github.com/documentcloud/underscore/issues/211),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L589-608)]

*`_.groupBy` should add values to own, not inherited, properties[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L623-630)]

*`_.isElement` should use strict equality for its duck type check[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L704-713)]

*`_.isEmpty` and`_.size` should support jQuery/MooTools DOM query collections[[#690](https://github.com/documentcloud/underscore/pull/690),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L740-745)]

*`_.isEqual` should return`true` for like-objects from different documents[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L781-801)]

*`_.isObject` should avoid V8 bug[#2291](http://code.google.com/p/v8/issues/detail?id=2291)[[#605](https://github.com/documentcloud/underscore/issues/605),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L809-821)]

*`_.isNaN(new Number(NaN))` should return`true`[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L829-831)]

*`_.keys` and`_.size` should work with`arguments` objects cross-browser[[#396](https://github.com/documentcloud/underscore/issues/396),[#653](https://github.com/documentcloud/underscore/issues/653),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L885-887)]

*`_.once` should free the given function for garbage collection[[#693](https://github.com/documentcloud/underscore/pull/693)]

*`_.range` should coerce arguments to numbers[[#634](https://github.com/documentcloud/underscore/issues/634),[#683](https://github.com/documentcloud/underscore/issues/683),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L1050-1053)]

*`_.reduceRight` should pass correct callback arguments when iterating objects[[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L1061-1075)]

*`_.size` should return the`length` of string values[[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L1120-1122)]

*`_.size` shouldn’t error on falsey values[[#650](https://github.com/documentcloud/underscore/pull/650),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L1124-1131)]

*`_.sortedIndex` should support arrays with high`length` values[[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L1210-1219)]

*`_.template` should not augment the`options` object[[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L1234-1238)]

*`_.throttle` should work when called in a loop[[#502](https://github.com/documentcloud/underscore/issues/502),[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L1330-1340)]

*`_.zipObject` should accept less than two arguments[[test](https://github.com/bestiejs/lodash/blob/v0.5.1/test/test.js#L1457-1459)]

*`_.range` should coerce arguments to numbers[[#634](https://github.com/documentcloud/underscore/issues/634),[#683](https://github.com/documentcloud/underscore/issues/683),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L1110-1113)]

*`_.reduceRight` should pass correct callback arguments when iterating objects[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L1121-1135)]

*`_.size` should return the`length` of string values[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L1179-1181)]

*`_.size` shouldn’t error on falsey values[[#650](https://github.com/documentcloud/underscore/pull/650),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L1183-1190)]

*`_.sortedIndex` should support arrays with high`length` values[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L1269-1278)]

*`_.template` should not augment the`options` object[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L1293-1297)]

*`_.throttle` should work when called in a loop[[#502](https://github.com/documentcloud/underscore/issues/502),[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L1389-1399)]

*`_.toArray` uses custom`toArray` methods of arrays and strings[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L1426-1434)]

*`_.zipObject` should accept less than two arguments[[test](https://github.com/bestiejs/lodash/blob/v0.5.2/test/test.js#L1520-1522)]

* Ensured`_.isElement` uses strict equality for its duck type check

* Ensured`_.isObject` returns a boolean value

* Ensured`_.template` and*“Objects”* methods don’t error when passed falsey values

* Made`_.template` generate less unused code in compiled templates

* Ensured`_.bind` correctly appends array arguments to partially applied arguments in older browsers

* Added support for exiting`_.forEach`,`_.forIn`, and`_.forOwn` early by returning`false` in the`callback`

* Added support for jQuery/MooTools DOM query collections to`_.isEmpty` and`_.size`

* Ensured development build works with IE conditional compilation enabled

* Ensured`_.clone` doesn't clone functions, DOM nodes,`arguments` objects, and objects created by constructors other than`Object`

* Ensured`_.filter`’s`callback` can't modify result values

* Ensured`_.clone` doesn’t clone functions, DOM nodes,`arguments` objects, and objects created by constructors other than`Object`

* Ensured`_.filter`’s`callback` can’t modify result values

* Ensured`_.isEmpty`,`_.isEquals`, and`_.size` support`arguments` objects

* Ensured`_.isEqual` doesn't inspect DOM nodes, works with objects from other documents, and calls custom`isEqual` methods before checking strict equality

* Ensured`_.isEqual` doesn’t inspect DOM nodes, works with objects from other documents, and calls custom`isEqual` methods before checking strict equality

* Ensured`_.once` frees the given function for garbage collection

* Ensured`_.sortBy` performs a stable sort

* Ensured`reEvaluateDelimiter` is assigned when`_.templateSettings.evaluate` is undefined

Lo-Dash is part of the BestieJS*"Best in Class"* module collection. This means we promote solid browser/environment support, ES5 precedents, unit testing, and plenty of documentation.

Lo-Dash is part of the BestieJS*“Best in Class”* module collection. This means we promote solid browser/environment support, ES5 precedents, unit testing, and plenty of documentation.

### <a id="_toarraycollection"></a>`_.toArray(collection)`

Converts the`collection`,into an array. Useful for converting the`arguments` object.

Converts the`collection`,to an array. Useful for converting the`arguments` object.

1.`collection` *(Array|Object|String)*: The collection to convert.

$markdown =docdown(array(

'path' =>'../' .$file,

'title' =>'Lo-Dash ^v0.5.1',

'title' =>'Lo-Dash ^v0.5.2',

'url' =>'https://github.com/bestiejs/lodash/blob/master/lodash.js'

));