How to wait for 2 or more promises to resolve in JavaScript

Oct 25, 2019

Learn how to wait for two or more promises to resolve in JavaScript with Promise.all(), reading the results from the returned array, using await or then().

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Say you need to fire up 2 or more promises and wait for their result.

And you want to go on, once you have both resolved.

How can you do so, in JavaScript?

You use Promise.all():

const promise1 = //...
const promise2 = //...

const data = await Promise.all([promise1, promise2])

const dataFromPromise1 = data[0]
const dataFromPromise2 = data[1]

If you prefer using pure promises and not async/await, use this syntax:

const promise1 = //...
const promise2 = //...

Promise.all([promise1, promise2]).then(data => {
	const dataFromPromise1 = data[0]
	const dataFromPromise2 = data[1]
})

Tagged: JavaScript · All topics

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