# Symbols [](http://badge.fury.io/js/symbol) [ES6 Symbols](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-symbol-objects), in your ES5. If `Symbol` is already defined, it will be used. Otherwise, this implements as much of the `Symbol` spec as is possible with plain JavaScript. ## Usage ```js var Symbol = require('symbol'); var key = Symbol(); var obj = {}; obj[key] = 'foo'; console.log(obj[key]); // 'foo' console.log(Object.keys(obj)); // [] ```