Knowledge for the World

How to copy an object in JavaScript

Making a deep copy of an object in JavaScript is fairly challenging. Fortunately, there are a few ways to accomplish this without much code.


jQuery provides an extend method that enables you to create both shallow and deep copies of an object.

// Shallow copy
var newObj = jQuery.extend({}, oldObj);

// Deep copy
var newObj = jQuery.extend(true, {}, oldObj);


A vanilla JavaScript hack that doesn't require much code involves using the JSON library. You can stringify an object and then immediately parse it like this:

var me = {
    name: 'Tyler',
    age: 29

var me2 = JSON.parse(JSON.stringify(me)); = 'Joseph';


This is obviously not the intent of this library, but it works apart from copying functions.