Tech Mahindra Interview Questions and Answers

Event loop is a mechanism in Node.js that allows non-blocking I/O operations to be performed asynchronously.

• Event loop continuously checks the call stack for any functions that need to be executed.

• It offloads I/O operations to the system kernel and executes callbacks when the operations are completed.

• Event loop ensures that Node.js remains responsive and can handle multiple requests concurrently.

A promise is an object representing the eventual completion or failure of an asynchronous operation.

• Promises are used to handle asynchronous operations in JavaScript.

• They can be in one of three states: pending, fulfilled, or rejected.

• Promises can be chained together using .then() method.

• They help avoid callback hell and make code more readable and maintainable.

The event loop is a mechanism in Node.js that allows for non-blocking I/O operations by handling asynchronous tasks.

• Handles asynchronous tasks by executing callback functions when I/O operations are completed

• Ensures that the Node.js application remains responsive by not blocking the main thread

• Uses a single-threaded model to process multiple tasks concurrently