my 2 cents

I found this nice introduction to javascript closures.

In some points I find it a bit oversimplified, but the examples are great. A deeper look into the obscures of javascript can be found in the nice book JavaScript: The Definitive Guide, 5th Edition by David Flanagan (O’Reilly Media, 2001).

I’m not fully through this book (994 pages) but I find it extremely helpful as javascript is quite different to languages like C++ or PHP.