What's the difference between ‘var $x’ and ‘var x’ in javascript? [duplicate]

This question already has answers here: 开发者_如何学编程 Closed 13 years ago.

What's the difference between var $x and var x in javascript?

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Nothing. People tend to use the $x syntax because it's easier to remember you're dealing with a jquery object rather than an element or an id.

In general I tend to use something similar to:

var $x = $(selector) //$x holds reference to a jquery object
var elX = document.getElementById(id); // elX hold ref to an element node
var xId = $(selector).attr('id'); //xId holds ref to an id attribute

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The difference? One variable starts with $.

And neither has anything to do with jQuery - it's just javascript.

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One declares a variable called $x, one declares a variable called x. Dollar is a perfectly valid character for a variable name in JavaScript (this isn't really specifically jQuery related as far as I can see).

See "Why would a javascript variable start with a dollar sign?" for more.

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There is no difference between two in JavaScript. $ is allowed in variable declaration in JavaScript

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The dollar prefix is often used in Javascript for global variables. It's merely a convention - Like underscore is often used to denote a private member.