How do asynchronous operations work with arrays in JavaScript?

How do asynchronous operations work with arrays in JavaScript?

In JavaScript, asynchronous operations can be handled using promises, async/await, or callbacks. When working with arrays, you can use methods like map, filter, or forEach in combination with these asynchronous techniques.

Can you give me an example using async/await with an array?

Sure! Here's a simple example:

const fetchData = async (url) => {
    const response = await fetch(url);
    return response.json();
};

const urls = ['url1', 'url2', 'url3'];

const fetchAllData = async () => {
    const results = await Promise.all(urls.map(fetchData));
    console.log(results);
};

fetchAllData();

What happens if one of the promises fails?

If one of the promises in Promise.all fails, it will reject immediately, and you can handle the error using a try/catch block around the await call.

Can I use forEach with async/await?

No, forEach does not work well with async/await because it doesn't wait for promises to resolve. Instead, use a for...of loop.