Hi Eric - looking at the table of contents for the pre-release version of your book, I see you are covering (what I consider) more advanced topics such as Polymorphism and Lambda functions. In other materials I've read, there seems to be some different opinions on how these are to be implemented properly in JavaScript. Would you care to comment on your approach to these topics in this book?
Also, would you recommend the pre-release eBook is available now or wait for the final version in October?
Thanks!