Sample code showing the use of async functions in Javascript

async.js

// Create a promise that is resolved after `timeout` ms
const promiseTimer = timeout => new Promise(resolve => setTimeout(() => resolve(null), timeout))

async function counter(max) {
	for(let i = 0; i < max; i++) {
		console.log("Counting:", i)

		// This is the important part. "await" allows the function to appear to block;
		// other asynchronous work can be done here. This is basically the equivelent
		// of a .then on promiseTimer
		await promiseTimer(500)
	}
	console.log("Done")
}

// Calling an async function returns a Promise.
counter(10).then(() => console.log("Finished async function"))