JavaScript Asynchronous Concepts Explained Simply

Mon, 01 Jan 0001 00:00:00 +0000

Promise

A JavaScript Promise is an object that represents the future result of an asynchronous operation.
It is used to handle operations such as fetching data, reading files, or calling an API.

Promises have three states:

Pending – the initial state, waiting for a result.
Fulfilled – the operation completed successfully.
Rejected – the operation failed.

You can create a promise using the Promise constructor:

const promise = new Promise((resolve, reject) => {
  setTimeout(() => resolve("Done!"), 1000);
});

promise.then(value => console.log(value)); // Output: Done!

In short: Promises help manage asynchronous tasks without using too many nested callbacks.

JavaScript on {O}

JavaScript Asynchronous Concepts Explained Simply

Promise