ECMAScript 6 features available in Node.js 0.12

Features without --harmony flag:

• “for-of” loop
• Map, Set, WeakMap, WeakSet (already specified in question)
• Symbol (already specified in question)
• Promise (already specified in question)
• Array methods:
  • .keys()
  • .values()
  • .entries()
  • [Symbol.iterator]
• Object:
  • .observe() (initially was planned for ES7, but was removed from the spec entirely on November 2, 2015)
  • .is()
  • .setPrototypeOf()
  • .getOwnPropertySymbols()
  • .getNotifier() (not es6, example here)
  • .apply() and .call() (not es6, same purpose as Funciton.prototype.call and Function.prototype.apply)
• Number properties and methods (already specified in question)
  • .isInteger()
  • .isSafeInteger()
  • .isNaN()
  • .isFinite()
  • EPSILON
  • MIN_SAFE_INTEGER
  • MAX_SAFE_INTEGER
• Math methods (a lot of them) (already specified in question)
• constants

I thinks that’s all that we have without --harmony flag.

Features with --harmony flag:

• generators
• arrow functions (without need of --harmony_arrow_functions flag in contrast to io.js)
• let variables – only in strict mode
• Binary and octal literals

• String methods:

  • .contains() (was replaced by includes() in actual ES6 specification)
  • .startsWith()
  • .endsWith()
  • .codePointAt()
  • .repeat()
  • .normalize()
  • String.fromCodePoint

• Proxy (behind the --harmony-proxies flag)

I think that’s all. Maybe if I forgot something – I’ll add it later to the list.