61_event_loop.js

// The event loop is a fundamental concept in JavaScript that allows it to handle asynchronous operations in a non - blocking manner.It's what enables JavaScript to perform tasks like making network requests or running animations without freezing up the entire application.

// At a high level, the event loop works by continuously checking for any pending events in the JavaScript runtime.When an event occurs, such as a user clicking a button or a network request completing, the event is added to a queue.

// The event loop then processes each event in the queue one at a time, in the order they were received.While the event is being processed, the JavaScript runtime is blocked and cannot execute any other code.Once the event has been fully processed, the event loop moves on to the next event in the queue.

// However, not all events are processed immediately.Some events, such as network requests or setTimeout() callbacks, are asynchronous and are not processed immediately when they are added to the event queue.Instead, they are placed in a separate queue called the "task queue".

// When the event loop is processing the event queue and there are no more events to process, it moves on to the task queue and begins processing the asynchronous tasks that are waiting there.Once all the tasks in the task queue have been processed, the event loop returns to processing the event queue.

// This cycle of processing events and tasks continues indefinitely as long as there are events and tasks in their respective queues.

// Overall, the event loop is a critical part of how JavaScript works, and understanding how it operates is essential for writing efficient and responsive applications.