What is Promise.all in Node.js?

Can you explain what Promise.all does in Node.js?

Sure! Promise.all is a method that takes an array of promises and returns a single promise that resolves when all of the promises in the array have resolved.

What happens if one of the promises fails?

If any promise in the array rejects, Promise.all immediately rejects with that reason, and the other promises are still executed.

Can you give me an example of how to use it?

Absolutely! Here's a simple example:

const promise1 = Promise.resolve(3);
const promise2 = new Promise((resolve, reject) => setTimeout(resolve, 100, 'foo'));

Promise.all([promise1, promise2]).then(values => {
  console.log(values); // [3, 'foo']
});

Is there a limit to how many promises I can pass to Promise.all?

No, there's no explicit limit, but keep in mind that too many concurrent promises can lead to performance issues.