ES6 classes solve this by providing JavaScript a clean, standardized syntax for classes. This new syntax is available in Chrome 42 for JavaScript written in strict mode.
The following ECMAScript 6 content is now supported by Safari:
Classes
[169] Bug 23225 – Let's start using class, not interface ( ( 版)) <https://www.w3.org/Bugs/Public/show_bug.cgi?id=23225>
[4] class Elements extends Array ( ( 版)) <https://gist.github.com/domenic/5864658>
[3] Comment out query/queryAll/Elements for now · whatwg/dom@10b6cf1 ( 版) <https://github.com/whatwg/dom/commit/10b6cf1ba02806220d5461a3bdb7939728b73635>
[6] 23225 – Let's start using class, not interface () <https://www.w3.org/Bugs/Public/show_bug.cgi?id=23225>
[7] Consider syntactic changes to WebIDL to make it more "JavaScript-y" · Issue #485 · heycam/webidl () <https://github.com/heycam/webidl/issues/485>
Elementsも参照。