Have ideas to improve npm?Join in the discussion! »

    DefinitelyTyped icon, indicating that this package has TypeScript declarations provided by the separate @types/lodash package

    0.6.1 • Public • Published

    Lo-Dash v0.6.1

    A drop-in replacement* for Underscore.js, from the devs behind jsPerf.com, delivering performance, bug fixes, and additional 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.


    Dive in

    We’ve got API docs, benchmarks, and unit tests.

    Create your own benchmarks at jsPerf, or search for existing ones.

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


    For more information check out these screencasts over Lo-Dash:



    Lo-Dash has been tested in at least Chrome 5-21, Firefox 1-15, IE 6-9, Opera 9.25-12, Safari 3-6, Node.js 0.4.8-0.8.8, Narwhal 0.3.2, RingoJS 0.8, and Rhino 1.7RC5.

    Custom builds

    Custom builds make it easy to create lightweight versions of Lo-Dash containing only the methods you need. We handle all the method dependency and alias mapping for you.

    • Backbone builds, containing all methods required by Backbone, may be created using the backbone modifier argument.
    lodash backbone
    • CSP builds, supporting default Content Security Policy restrictions, may be created using the csp modifier argument.
    lodash csp
    • Legacy builds, tailored for older browsers without ES5 support, may be created using the legacy modifier argument.
    lodash legacy
    • Mobile builds, with IE < 9 bug fixes and method compilation removed, may be created using the mobile modifier argument.
    lodash mobile
    • Strict builds, with _.bindAll, _.defaults, and _.extend in strict mode, may be created using the strict modifier argument.
    lodash strict
    • Underscore builds, containing only methods included in Underscore, may be created using the underscore modifier argument.
    lodash underscore

    Custom builds may be created in three ways:

    1. Use the category argument to pass the categories of methods to include in the build.
      Valid categories are “arrays”, “chaining”, “collections”, “functions”, “objects”, and “utilities”.
    lodash category=collections,functions
    lodash category="collections, functions"
    1. Use the exclude argument to pass the names of methods to exclude from the build.
    lodash exclude=union,uniq,zip
    lodash exclude="union, uniq, zip"
    1. Use the include argument to pass the names of methods to include in the build.
    lodash include=each,filter,map
    lodash include="each, filter, map"

    All arguments, except backbone with underscore, exclude with include, and legacy with csp/mobile, may be combined.

    lodash backbone legacy category=utilities exclude=first,last
    lodash underscore mobile strict category=functions include=pick,uniq

    The lodash command-line utility is available when Lo-Dash is installed as a global package (i.e. npm install -g lodash).

    Custom builds are saved to lodash.custom.js and lodash.custom.min.js.

    Installation and usage

    In browsers:

    <script src="lodash.js"></script>

    Using npm:

    npm install lodash
    npm install -g lodash

    In Node.js and RingoJS v0.8.0+:

    var _ = require('lodash');

    In RingoJS v0.7.0-:

    var _ = require('lodash')._;

    In Rhino:


    In an AMD loader like RequireJS:

      'paths': {
        'underscore': 'path/to/lodash'
    ['underscore'], function(_) {

    Resolved Underscore.js issues (30+)

    • Allow iteration of objects with a length property [#148, #154, #252, #448, #659, test]
    • Ensure array-like objects with invalid length properties are treated like regular objects [test]
    • Ensure “Arrays”, “Collections”, and “Objects” methods don’t error when passed falsey arguments [#650, test]
    • Ensure “Collections” methods allow string collection arguments [#247, #276, #561, test]
    • Ensure templates compiled with errors are inspectable [#666, test]
    • Fix cross-browser object iteration bugs [#60, #376, test]
    • Handle arrays with undefined values correctly in IE < 9 [#601]
    • Methods should work on pages with incorrectly shimmed native methods [#7, test]
    • Register as an AMD module, but still export to global [#431, test]
    • _(…) should return passed wrapper instances [test]
    • _.clone should allow deep cloning [#595, test]
    • _.contains should work with strings [#667, test]
    • _.countBy and _.groupBy should only add values to own, not inherited, properties [test]
    • _.escape should return an empty string when passed null or undefined [#427, test]
    • _.extend should recursively extend objects [#379, #718, test]
    • _.forEach should be chainable [#142, test]
    • _.forEach should allow exiting iteration early [#211, test]
    • _.isElement should use strict equality for its duck type check [test]
    • _.isEmpty and _.size should support jQuery/MooTools DOM query collections [#690, test]
    • _.isEqual should return true for like-objects from different documents [test]
    • _.isObject should avoid V8 bug #2291 [#605, test]
    • _.isNaN(new Number(NaN)) should return true [test]
    • _.keys and _.size should work with arguments objects cross-browser [#396, #653, test]
    • _.once should free the given function for garbage collection [#693]
    • _.range should coerce arguments to numbers [#634, #683, test]
    • _.reduceRight should pass correct callback arguments when iterating objects [test]
    • _.size should return the length of string values [test]
    • _.sortedIndex should support arrays with high length values [test]
    • _.template should not augment the options object [test]
    • _.throttle should work when called in a loop [#502, test]
    • _.toArray uses custom toArray methods of arrays and strings [test]
    • _.zipObject should accept less than two arguments [test]

    Optimized methods (50+)

    • _.bind
    • _.bindAll
    • _.clone
    • _.compact
    • _.contains, _.include
    • _.defaults
    • _.defer
    • _.difference
    • _.drop, _.omit
    • _.each
    • _.escape
    • _.every, _.all
    • _.extend
    • _.filter, _.select
    • _.find, _.detect
    • _.flatten
    • _.forEach, _.each
    • _.functions, _.methods
    • _.groupBy
    • _.indexOf
    • _.intersection
    • _.invoke
    • _.isArguments
    • _.isDate
    • _.isEmpty
    • _.isFinite
    • _.isFunction
    • _.isObject
    • _.isNumber
    • _.isRegExp
    • _.isString
    • _.keys
    • _.lastIndexOf
    • _.map, _.collect
    • _.max
    • _.memoize
    • _.min
    • _.mixin
    • _.pick
    • _.pluck
    • _.reduce, _.foldl, _.inject
    • _.reject
    • _.result
    • _.shuffle
    • _.some, _.any
    • _.sortBy
    • _.sortedIndex
    • _.template
    • _.throttle
    • _.times
    • _.toArray
    • _.union
    • _.uniq, _.unique
    • _.values
    • _.without
    • _.wrap
    • _.zip
    • plus all _(…) method wrappers

    Release Notes


    • Ensured IE conditional compilation isn’t enabled by the useSourceURL test
    • Optimized isPlainObject


    • Added callback and thisArg arguments to _.drop and _.pick
    • Added hasObjectSpliceBug test to avoid delete operator use
    • Added _.omit alias for _.drop
    • Added _.unescape
    • Ensured _.reduce works with string objects in IE < 9
    • Made compiled methods take advantage of engines with strict mode optimizations
    • Optimized _.intersection and removed its dependency on _.every
    • Reduced the file size of the underscore build

    The full changelog is available here.


    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.




    npm i [email protected]







    Last publish


    • avatar
    • avatar
    • avatar