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var extend = require("extend")

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extend v3.0.2

Port of jQuery.extend for node.js and the browser

Build Status dependency status dev dependency status

extend() for Node.js Version Badge

node-extend is a port of the classic extend() method from jQuery. It behaves as you expect. It is simple, tried and true.


  • Since Node.js >= 4, Object.assign now offers the same functionality natively (but without the "deep copy" option). See ECMAScript 2015 (ES6) in Node.js.
  • Some native implementations of Object.assign in both Node.js and many browsers (since NPM modules are for the browser too) may not be fully spec-compliant. Check object.assign module for a compliant candidate.


This package is available on npm as: extend

npm install extend


Syntax: extend ( [deep], target, object1, [objectN] )

Extend one object with one or more others, returning the modified object.


var extend = require('extend');
extend(targetObject, object1, object2);

Keep in mind that the target object will be modified, and will be returned from extend().

If a boolean true is specified as the first argument, extend performs a deep copy, recursively copying any objects it finds. Otherwise, the copy will share structure with the original object(s). Undefined properties are not copied. However, properties inherited from the object's prototype will be copied over. Warning: passing false as the first argument is not supported.


  • deep Boolean (optional) If set, the merge becomes recursive (i.e. deep copy).
  • target Object The object to extend.
  • object1 Object The object that will be merged into the first.
  • objectN Object (Optional) More objects to merge into the first.


node-extend is licensed under the MIT License.


All credit to the jQuery authors for perfecting this amazing utility.

Ported to Node.js by Stefan Thomas with contributions by Jonathan Buchanan and Jordan Harband.


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