Counting frequency of character

Thanks. Well I did a Javascript course a couple of years ago and I started yesterday to refresh what I’ve learned. The course didn’t include objects to instead teach JQuery, something that I didn’t think it was a good option.
Before refreshing JS I was practising with Python. I have a good book Python for Everyone, with tons of exercises. Although there’s a jump between the theory and the practice.
I wish there was a very good book to learn JS, something like a mix of Head First JS, with Python for Everyone but including a step by step approach that everyone needs for learning.
I have some of the Sitepoint books, but for example JS Novice put me off after they start with that .core file that throws away the step by step process by including something that it’s not explained and that makes it impossible to reproduce as from then on, one needs that .core file.
Another very good model for a complete book would be Jump Start JS, but covering the whole of the language like that complete reference by O’Reilly: JS The Definite Guide. It could be written collaboratively by different authors.
Books sometime have non authentic examples: like an object with dog.bark etc…Anyway, it seems that programmers need to include someone who knows about education for producing books. Hope Sitepoint can evolve in this direction.