Javascript object initialization, which is the best way to do it?

Question

Object initialization:

var myObject = {};

and

var myObject = new Object();

why the last one is considered an antipattern?

thanks

Answer 1

I'm not sure new Object() really falls under "anti-pattern", but {} is usually preferred, it's terse and more flexible at the same time.

When you're writing JavaScript you want it to end up short...if it can be terse and understandable when writing it as well, as this is:

var myObject = { key: "value" };

...then you get the best of both worlds. Also when you're creating objects within objects, for example:

var myObject = { subObj: { key: "value" } };

...then you can see it's much more readable than the alternative new Object() syntax.

Answer 2

You always should prefer literals over constructors.

This is not really related to your question but here is an example with arrays. new Array() can be confusing at the first glance if you don't know how it works:

var a = [5,6];
var b = [5];

both create arrays with length 2 and 1 resp. But consider

var a = new Array(5,6);
var b = new Array(5);

The first one creates an array of length 2 ,containing the elements 5 and 6, the last one creates an empty array of length 5.

So you see, using literal notation avoids this pitfall.

Besides that, always using literal notation is consistent. When you create a string you also write var t = "Hello world" and not var t = new String("Hello world").