Documentation missing layers? and c++ or js

http://www.cocos2d-x.org/docs/static-pages/theBasics.html

This link is missing the documentation for layers.
What are layers and where can we use them?

Event handlers documentation is only giving examples in c++. Javascript examples are missing.
I see mostly c++ examples for cocos2d-x

Is c++ better than javascript.
Should i learn c++?

Please advice

Thanks

The team is still working on the new documentation you’re linking to. You can still access the old documentation though… link

Layers in cocos have a few special properties. Look at the tests to see how they can be used.

c++ has better performance, but a more steep learning curve, javascript has the advantage that it also works in the browser. For a casual game, javascript is more than able.