What is the difference between using Promises and async/await in JavaScript?

What is the difference between using Promises and async/await in JavaScript?

Promises are objects that represent the eventual completion or failure of an asynchronous operation, while async/await is syntactic sugar built on top of Promises that allows for a more synchronous-looking code structure.

Can you give me an example of both?

Sure! Here's a Promise example:

fetch('https://api.example.com/data')
  .then(response => response.json())
  .then(data => console.log(data))
  .catch(error => console.error(error));

And here's the async/await version:

async function fetchData() {
  try {
    const response = await fetch('https://api.example.com/data');
    const data = await response.json();
    console.log(data);
  } catch (error) {
    console.error(error);
  }
}
fetchData();

Which one is better to use?

It depends on the context. Async/await can make your code cleaner and easier to read, especially when dealing with multiple asynchronous operations. However, Promises are still very useful and can be more flexible in certain scenarios.

Are there any performance differences?

In general, there are no significant performance differences between the two. Both are built on the same underlying mechanism, but async/await can lead to more readable code, which can indirectly improve maintainability and development speed.