Today I Learned - Rocky Kev

TIL functional async/await

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TAGS: promises javascript node

I struggle with getting async/await written correctly.

This is a simple example of async/await used to run a function asynchronously:

const doSomethingAsync = () => {
  return new Promise((resolve) => {
    setTimeout(() => resolve('I did something'), 3000)
  })
}

const doSomething = async () => {
  console.log(await doSomethingAsync())
}

console.log('Before');
doSomething();
console.log('After');

The above code will print the following to the browser console:

Before
After
I did something // after 3s

So the line of thinking is:

  1. We hit the console.log('Before');
  2. We fire off the doSomething function, which is going to return a Promise with a setTimeout.
  3. We hit the console.log('After');
  4. We finally get the data back from doSomething, as it resolves it's Promise.

via The definitive Node.js handbook – Learn Node for Beginners

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