How can I use Promise.all in JavaScript?

How can I use Promise.all in JavaScript?

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.

Can you give me an example of how it works?

Sure! Here's a simple example:

const promise1 = Promise.resolve(3);
const promise2 = new Promise((resolve, reject) => setTimeout(resolve, 100, 'foo'));
const promise3 = 42;

Promise.all([promise1, promise2, promise3]).then(values => {
  console.log(values); // Output: [3, 'foo', 42]
});

What happens if one of the promises fails?

If any promise in the array rejects, Promise.all will reject with that error, and the other results will be ignored.

Is there a way to handle individual promise failures?

Yes! You can use Promise.allSettled, which waits for all promises to settle (either resolved or rejected) and returns an array of objects with the status and value.