I've been developing javascript for web applications and large consumer web sites for 10 years. Functional to OO to JSON notation. The ability to create a private function is a neat theoretical exercise, but the amount of code or change in coding patterns necessary to implement private functions is complete overkill.<p>Unless you are developing a huge javascript driven application, it does not actually matter if a method is private or public. Just don't call it. Much simpler/cleaner code, easier to read, easier to maintain. I'm a big proponent of making code simple instead of complex and private functions in javascript just add complexity.<p>Now, although I am skeptical, I would love to hear other commentors experience where they found private functions in javascript to be invaluable. What have you coded where making a method private added value to your code making it worth the increased complexity?