JavaScript variable declaration

Question

What's the difference between following types of var declaration in JavaScript?

$x

var x

var $x

Answer 1

$x and x are simply two different variable names. Like var x and var y. Simply using $x is an implied declaration, except that if $x exists in a higher scope, you'll use it. declaring var $x sets up a new $x in the current scope which avoids conflicts with any other $x at a higher scope.

Answer 2

No difference except for scope. $x is just a variable name like x. var creates variables in a local scope, otherwise they are global.

This has nothing to do with jQuery, really.