Javascript: $$ Global Variable Considered Evil?

I am writing a lot of Javascript code these days and I am making good use of JQuery. I am wondering if it is considered evil to create strange global variable names. I know that a lot of Javascript frameworks such as JQuery use the dollar character; $, but that greatly simplifies code as it can do so many things.

I am thinking of creating a $$ global variable in my code which would be defined as below:

function $$(tagName) 
{ 
    return $('<' + tagName + ' />'); 
}

The benefit of this is that my code has (1) abstracted out the logic of creating a new element, (2) made the code more 开发者_如何学编程concise, and lastly (3) I can almost create html elements within Javascript as concisely as html itself because JQuery has so many other selectors to chain off:

$$('div').attr( { id : 'myDiv', 'class' : 'MyDivClass' }).append(
    $$('ul').append(
        $$('li').text('first'),
        $$('li').text('second'),
        $$('li').text('third')
    );
);

Do you believe the above approach of creating $$ is legitimate or would you regard it as a no-no?

This is of course an opinion, but if I was new to your application, I would have to go look up what that function does in order to understand the code. Also, the function is simple enough that other developers would likely not bother using it, so you'd end up with a mix of techniques which is confusing.. And really, is this so bad?

$('<div/>').attr( { id : 'myDiv', 'class' : 'MyDivClass' }).append(
    $('<ul/>').append(
        $('<li/>').text('first'),
        $('<li/>').text('second'),
        $('<li/>').text('third')
    )
);

I prefer a clear, meaningful, self-documenting name over JQuery style $ any day of the year.

Also I find it confusing that the same name has different meanings depending on the context it is used in. Like $ in JQuery or this in javascript and will avoid using them as much as I can.

EDIT: In my opinion it should be up to the user to decide whether he wants to use a shorthand name for the framework he uses. It requires only one line of code:

var $ = jQuery;

When I look at pages with jQuery in it, all I see is a big mess flooded with dollar signs that do different things in different places. If the library had used meaningful names for the functions it offers it would be a lot easier to decipher other peoples code. Javascript is already difficult and unreadable as a language itself.

Personally I don't think it's adding that much functionality to account for the "namespace pollution", not to mention the possible confusion of people reading your code that aren't familiar with your method.

It's just saving a trivial couple of characters on each invocation of the method, so in that respect it can only be considered a form of syntactic sugar. And the cons outweigh the pros, in my opinion.

It would be good if you take a look at the construction of e.g. jQuery . It does'nt work with several global variables/functions, there is only one global object required "jQuery" . Everything else are properties of this one object, so they have minified naming-conflicts.

In the special case of $$ : maybe sometimes you need to work with prototypejs, but you cant, because prototypejs already uses $$.

So my suggestion: create one global object, your own "library" , give it a distinct name, and let your functions/variables be member of this object.

I don't think it's "evil" in general, but if you're going to pop something into the global namespace with a "distinguished" name it might be better if it were something a little more interesting. For your purposes, given your example code, the jQuery micro-template system would probably be a better approach anyway.