CODEWITHSUNDEEP
javascriptjquerycoding-style
Ranjit Singh
Ranjit Singh

Reputation: 3735

Difference between defining variable as var $a=$() and var a?

Sometimes in JQuery we define variable as var $a=$() which is like declaring a function. So i want to know does it make any change if we define variable as var a only?

Upvotes: 8

Views: 1292

Answers (5)

Alcides Queiroz
Alcides Queiroz

Reputation: 9576

$ is an allowed character in JS identifiers, it makes no difference. $(obj) wraps the object obj with a jQuery object, and decorates obj with a lot of additional behavior.

These are legal Javascript variable names:

$a=1;
a$$$=1;
$a=1;

The function $ is an alias for jQuery, if you do something like:

your HTML:

<img src='logo.png' id='site_logo'/>

your JS:

var logo = $('#site_logo');
logo.fadeOut();

The method fadeOut doesn't belongs to the img element, but to the jQuery wrapper.

Upvotes: 1

Konstantin Dinev
Konstantin Dinev

Reputation: 34905

Basically this is an allowed violation of Crockford's coding convention for javascript. It is used to differentiate jQuery objects from javascript DOM elements.

E.g.

var a = document.getElementById('a'); // DOM element
var $a = $(a); // jQuery object for the DOM element with ID 'a'

Upvotes: 2

Sushanth --
Sushanth --

Reputation: 55750

Generally I prefer naming jQuery objects prepended with a $ sign.. It's a convention to recognize jQuery objects in your code..

But it's just another variable name ;;

var a = 2;
var $a = $('#something');

Upvotes: 2

Justin Niessner
Justin Niessner

Reputation: 245459

If you mean:

var a = $(/* Object or Selector gets passed here */)

Then the only difference would be the name. Developers use $a to indicate that the value is already jQuery-ied. Leaving it off changes no functionality but would be a dis-service to future developers.

Upvotes: 4

Kevin B
Kevin B

Reputation: 95047

no, it is no different. $a is the same as a in that context. It's simply a variable name.

Upvotes: 2

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