Question

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

what difference does the $ at the beginning of anonymous function?

This Example:

(function() {
  ...
})();

Versus this one:

$(function() {
  ...
})();

Answer 1

(function() {})();

The line above is creating an anonymous function and then executes it right away

$(function() {})();

Assuming you have jQuery loaded, the line above causes an error. This part $(function(){}) will pass an anonymous function into jQuery that gets run. jQuery will return a Document object back to you. Because you have the ending parenthesis () the Javascript will try to execute the Document object as a function. Because the Document object is not a function, a TypeError exception will be raised.