What is Promise in JavaScript| JavaScript Tutorials in Hindi | Interview Question #43
In JavaScript, a promise is an object representing the eventual completion or failure of an asynchronous operation. It allows you to handle asynchronous operations more easily and effectively by providing a cleaner syntax than traditional callback-based approaches.
A promise can be in one of three states:
- Pending: Initial state, neither fulfilled nor rejected.
- Fulfilled: The operation completed successfully.
- Rejected: The operation failed.
Promises have methods to handle these states:
then(): This method is used to specify what to do when a promise is fulfilled or rejected.
Promises are commonly used for asynchronous operations such as fetching data from a server, reading files, or making network requests. They provide a more readable and maintainable way to work with asynchronous code compared to nested callbacks.
