If you love to learn how to program in Javascript, you would be happy to know about Codecademy.
Maybe it’s too easy for who has some experience, but in the end it’s useful, and with the gamification of the lessons, it’s funny to collect all the badges, here is my profile, with all badges collected, hahaha).
If you don’t have any programming experience, it’s useful because it explains very well.
If you, like me, learned Javascript by yourself, it’s still useful; maybe sometimes it’s a little bit boring, but there is still something that you didn’t know about, for example I had no idea what a ternary operator was (Even if, during the rest of the course, you are asked to use the classic if-else in situations where the ternary operator will be perfect).
If you are a professional, this course it’s totally useless – maybe you can think about it as a typing lesson 😝
Right now there are only Javascript lessons, in future Python and Ruby courses will be added.