What real purpose does $.noop() serve in jQuery 1.4?

Question

Pouring over the release notes regarding jQuery 1.4, I came acrosss $.noop() which is:

Description: An empty function. (added in 1.4)

Answer 1

If you have a function that accepts a function as a parameter, and you don't have any code to give it, you can pass $.noop.

I can't think of any such cases in jQuery where the parameter isn't optional in the first place, though.

Unlike writing function(){}, passing $.noop will not create a new function instance, saving a bit of memory. However, if whatever you're passing it to modifies the function object (eg, funcParam.id = 2), passing $.noop will mess things up.