How do I make a copy of a JavaScript object?

Question

I need to make a temporary copy of a variable to make changes to. Here's what I mean:

var x = ["a", "b", "c"];
var y = x;
y[1] = "2"
//x: ["a", "b", "c"];
//y: ["a", 2, "c"];

It's worth pointing out that I'm using an object I defined myself, and not a built in data structure.

Answer 1

The standard method for 'cloning' array of primitive types in JavaScript (based on your requirements) is shown below:

var x = ["a", "b", "c"];
var y =  x.slice(0);
y[1] = "2";

Be aware, that if array contains complex types (objects), then it will keep original references; in other words, it does not perform 'deep' copy on array of objects.

Answer 2

Try this

var x = ["a", "b", "c"];
var y = JSON.parse(JSON.stringify(x));
//y = ["a", "b", "c"];

Then u can manipulate your new object as u want.

Answer 3

You can use jQuery to clone your object

var newObject = jQuery.extend(true, {}, oldObject);

jQuery Documentation