4.7.1 Promise.all
HTML
<script src="https://rawgit.com/eu81273/jsfiddle-console/master/console.js"></script>
JavaScript
Promise.all([
new Promise(resolve => setTimeout(() => resolve('a'), 3000)),
new Promise(resolve => setTimeout(() => resolve('b'), 2000)),
new Promise(resolve => setTimeout(() => resolve('c'), 1000))
]).then(console.log); // ['a','b','c']