[ameliaquining]

One warning: Although it's a good book, it was published in 2008 and a lot has been added to the language since then. It will give you a solid understanding of the core of the language, but for modern best practices you'll have to look elsewhere.

[ajeet_dhaliwal]

Agreed, I own this book and it was great several years ago but it does not include ES5, 6 and now 2016, 2017. I think you're better off learning online. Or to get started read it and then add to the knowledge here: http://es6-features.org/#Constants (whoever set up that site is great, it's helped me out).

[dhimes]

Where would you suggest?

[jensvdh]

MDN.

[jensv]

Hello there jensvdh, pleased to make your acquaintance.

[jensvdh]

Always a pleasure to meet a fellow Jens!