Symbol
Widely available since 2018-03-30
A Symbol value is a unique, non-enumerable primitive value used for encapsulation or information hiding. For example, a symbol can be a key of an object that can never collide with any other key.
Learning resources on MDN
Browser support
- Chrome 38 Released on 2014-10-07
- Chrome Android 38 Released on 2014-10-08
- Edge 12 Released on 2015-07-29
- Firefox 36 Released on 2015-02-24
- Firefox for Android 36 Released on 2015-02-27
- Safari 9 Released on 2015-09-30
- Safari on iOS 9 Released on 2015-09-16
Specifications
- ECMAScript Language Specification (#sec-symbol-objects), from TC39 (Ecma International).