What does $('') mean in JavaScript? [duplicate]

Question

Possible Duplicate:
What is the meaning of “$” sign in javascript

I've encountered a code in JavaScript that looks like this:

$('svg circle').tipsy({ 
    gravity: 'w', 
    html: true, 
    title: function() {
      return 'Color: '; 
    }
});

What does $('') mean here?

Answer 1

Usually when you encounter $(), that means the developer is using a javascript library, such as jQuery.

The $ symbol is the namespace for those libraries. All the functions they define begin with $., such as $.get(). Passing the id of an html tag like this: $("#myId") will give you a jQuery object representing that node.

Answer 2

This is from using the jQuery library, which is used to standardize JavaScript usage between browsers and make accessing elements and other common tasks much, much easier. It is not a part of JavaScript itself, except insofar as $ is an acceptable name for a function or variable.