es6-symbol

es6-symbol

ECMAScript 6 Symbol polyfill

For more information about symbols see following links

• Symbols in ECMAScript 6 by Axel Rauschmayer
• MDN Documentation
• Specification

Limitations

Underneath it uses real string property names which can easily be retrieved, however accidental collision with other property names is unlikely.

Usage

It’s safest to use es6-symbol as a ponyfill – a polyfill which doesn’t touch global objects:

var Symbol = require('es6-symbol');

If you want to make sure your environment implements Symbol globally, do:

require('es6-symbol/implement');

If you strictly want to use polyfill even if native Symbol exists (hard to find a good reason for that), do:

var Symbol = require('es6-symbol/polyfill');

API

Best is to refer to specification. Still if you want quick look, follow examples:

var Symbol = require('es6-symbol');

var symbol = Symbol('My custom symbol');
var x = {};

x[symbol] = 'foo';
console.log(x[symbol]); 'foo'

// Detect iterable:
var iterator, result;
if (possiblyIterable[Symbol.iterator]) {
  iterator = possiblyIterable[Symbol.iterator]();
  result = iterator.next();
  while(!result.done) {
    console.log(result.value);
    result = iterator.next();
  }
}

Installation

NPM

In your project path:

$ npm install es6-symbol

Browser

To port it to Browser or any other (non CJS) environment, use your favorite CJS bundler. No favorite yet? Try: Browserify, Webmake or Webpack

Tests

$ npm test