Basic example about how to use async and await in ES7

async-await-example.js

function resolveAfter2Seconds(x) {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve(x);
    }, 2000);
  });
}
async function addTwoResult(a, b) {
  var first = await resolveAfter2Seconds(a);
  var second = await resolveAfter2Seconds(b);
  return first + second;
}

addTwoResult(3, 5)