Two argument variable in js?

Question

I'm trying to adapt some code that contains this line:

var nav = document.getElementById('access_nav'),
 body = document.body;

Could someone help me understand what I'm looking at?

At first I thought it was two variables being declared, 'nav' and 'body', but then I saw the comma, and I wondered if it was a variable 'nav' with two arguments.

Something else?

• John Hascall: It's what you think it is, but it is evil.
• XYZ: nav and body both is variable nav is a element with id="access_nav" and body is body tag is that clear ?
• XYZ: also you can every time not able to understanding put into console.log example console.log('what is this:', body)

Answer 1

That's two variables, you are right.

It is strictly equivalent to

var nav = document.getElementById('access_nav');
var body = document.body;

Which (in my opinion), is clearer. The simple existence of your question is enough for me to not like this notation.

Answer 2

It's just a shortcut to declare variables. It equals to:

var nav = document.getElementById('access_nav');
var body = document.body;

Answer 3

We have no 2-argument-variable in javascript. Its just a shorthand for declaring variables & from the POV of its context, Both following are the same:

this:

var nav = document.getElementById('access_nav'),
 body = document.body;

and this:

var nav = document.getElementById('access_nav');
var body = document.body;

Answer 4

@Bewildered

It is a multiple variable declaration in one line.

var nav = document.getElementById('access_nav'),
 body = document.body;

The traditional JavaScript version of these declarations is:

var nav = document.getElementById('access_nav'); // Grab an HTML element with an ID 'access_nav'
var body = document.body; // Store entire body of the document in a variable. Useful when you need to some later operations on it.