tbranyen

const bus = {};
const get = e => (bus[e] = bus[e] || new Set());

export const listeners = new Proxy(bus, { get });
export const emit = (e, ...args) => listeners[e].forEach(fn => fn(...args));

jonschlinkert

const longest = arr => arr.reduce((len, v) => Math.max(v.length, len), 0);

remarkablemark

JavaScript Classes - ES5 vs ES6

An example that shows the difference between creating a JavaScript class and subclass in ES5 and ES6.

Reference

padolsey

// ----------------------------------------------------------
// A short snippet for detecting versions of IE in JavaScript
// without resorting to user-agent sniffing
// ----------------------------------------------------------
// If you're not in IE (or IE version is less than 5) then:
//     ie === undefined
// If you're in IE (>=5) then you can determine which version:
//     ie === 7; // IE7
// Thus, to detect IE:
//     if (ie) {}