How to make alias in javascript

I've made a Utilities javascript "class" that performs some utility 开发者_如何学Gofunctions.

Instead of having to call Utilities.XYZ, I'd like to be able to do something like #.XYZ.

# is invalid identifier character in Javascript but you can use something else

var $U = Utilities;

this will make it possible to use $U.XYZ. Since $ is used by many Javascript libraries you can use $U as an alias for Utilities. Easy to understand/remember and short to type. This is aslo more versatile than single sign identifier, because you can define several aliases each for their own longer coutnerpart:

$A, $B, ... $Z

# isn't a legal identifier, but _ and $ are.

var $ = Utilities;

Note that $ is used by several libraries (including but not limited to jQuery, Prototype, and MooTools), and _ is used by underscore.js. And of course you can always add a character or two.

The full list of valid identifier characters is in the specification, but essentially, an identifier may start with $, _, or any alphabetic character; and then subsequent characters may be any of those as well as digits and (in recent versions of JavaScript) accented letters in various languages.