What is the Node.js event loop and how does it work?

What is the Node.js event loop and how does it work?

The Node.js event loop is a mechanism that allows Node.js to perform non-blocking I/O operations. It enables asynchronous programming by handling multiple operations concurrently without blocking the main thread.

Can you explain how the event loop handles callbacks?

Sure! The event loop processes callbacks in a queue. When an asynchronous operation completes, its callback is added to the queue, and the event loop executes it when the call stack is empty.

What are the phases of the event loop?

The event loop has several phases: timers, I/O callbacks, idle, poll, check, and close callbacks. Each phase has a specific purpose in managing asynchronous operations.

How does the event loop differ from traditional threading?

Unlike traditional threading, which can create multiple threads for concurrent execution, the event loop uses a single-threaded model to handle multiple operations, making it more efficient for I/O-bound tasks.

Can you give an example of how the event loop works in a simple Node.js application?

Certainly! In a simple Node.js app, when you make a database query, the event loop allows the app to continue executing other code while waiting for the query to complete. Once the query finishes, its callback is executed.