Which version of javascript engine?

Hi folks.

I found that some ESNext features are already usable on codingame.
For example :

  • let keyword (block scoped variables)
  • arrow functions (short-syntax functions with automatic this binding
  • destructuring (automatic variable extraction from arrays/objects)

Is it possible to know which javascript engine (node, io, vertex, nashorn…) is used ?

Thanks a lot.

Hey @damien_feugas,

It’s a bit hidden, but can be found in the FAQs

For JavaScript it is SpiderMonkey 31.2 (JavaScript 1.8.5)

Thank you, and sorry not to have searched enough.

It’s pretty difficult to have a clear status of which es6 feature is availabl, but we can say that spidermonkey version is equivalent to Firefox (gecko) version.

Therefore, any feature on that page supported by firefox 31 (or previous versions) are available.
The main unsupported ES6 features are:

  • tail call optimization
  • object literals
  • template strings
  • classes
  • WeakSet
  • Symbol

A summary is available at Kangax

Still, engouh stuff to have a lot of fun !