Event Loop in JavaScript

In JavaScript, the event loop plays an important role in managing asynchronous operations and ensures the non-blocking behavior of the language. JavaScript is single-threaded, meaning it processes one task at a time and an event loop helps to handle asynchronous tasks efficiently. When an asynchronous operation, like a setTimeout callback or a user event, is initiated, it gets delegated to the browser’s APIs, allowing the main thread to remain unblocked. Once the operation is complete, a callback function is placed in the callback queue.

The event loop continuously checks two main components: the call stack and the callback queue. The call stack keeps track of the currently executing function or task, while the callback queue stores callback functions waiting to be processed. If the call stack is empty, the event loop takes the first callback from the queue and pushes it onto the call stack for execution.