What is the difference between callback functions and promises in Node.js?

Node.js Interview Question: What is the difference between callback functions and promises in Node.js?

Callback functions and promises are both used for handling asynchronous operations in Node.js. Here are the key differences between them:

Callback Functions:

• Callback functions are the traditional way of handling asynchronous operations in Node.js.
• They are passed as a parameter to asynchronous functions and are called once the operation is completed.
• Callback hell or callback pyramid can occur when multiple asynchronous operations are nested inside one another.
• Debugging and error handling can become complex with callback functions.

Promises:

• Promises are objects that represent the eventual completion or failure of an asynchronous operation.
• They allow you to chain multiple asynchronous operations together in a more readable and maintainable way.
• Promises provide a cleaner and more structured approach to handling asynchronous code compared to callback functions.
• They have built-in error handling mechanisms through which errors can be caught and handled asynchronously.

Overall, promises offer a more elegant and efficient solution for handling asynchronous operations in Node.js compared to traditional callback functions.