A free, up to date, possibly good book on JS programming? Flipping thru, a few things pop out at me.
This is a petty pet peeve, but I greatly dislike that he writes arrow functions without parens:
n => { return n * n; } instead of (n)=>{ return n * n; }
When they are required for multiple arguments: (x, y)=>{ return x * y; }
On first appearance, he dismisses arrow functions as just being shorter than function expressions, which is incorrect (arrows fix the 'this' reference which is never correct in function expressions). But then he consistently uses arrow functions (in his ugly parens-elided style), so crisis averted?
"Every now and then, usually between eight and ten in the evening, Jacques finds himself transforming into a small furry rodent with a bushy tail."
Which example then leads into a statistical analysis story, and the kind of data hackery that JS (and Python) are very good for.
The robot delivery example is another fairly detailed story with pathfinding, tho his algorithm is defective (it fails and/or consumes all memory forever on more complex graphs than the very simple one given).
I'll have a look at the rest of the book later.
None of the examples thus far actually build and run in a web page, or any sort of UI, except in the online document. You can copy-paste these examples into Safari's console and run them. I really don't think it's useful to learn a language outside the context of a running environment, so next post I'll give you one.