What is the function of an event loop in JavaScript?

The function of an event loop in JavaScript is to manage asynchronous operations and ensure that code is executed after the current execution stack is cleared. JavaScript is single-threaded, meaning it can only execute one piece of code at a time. However, many operations, such as network requests or timers, can occur asynchronously. The event loop plays a crucial role in handling these operations.

When an asynchronous operation completes, its callback function is placed in a queue. The event loop continuously checks if the call stack is empty. Once it becomes empty, the event loop takes the next callback from the queue and pushes it onto the call stack for execution. This mechanism allows JavaScript to efficiently manage tasks without blocking the main thread, thus providing a smooth user experience in applications.

The other options do not accurately describe the role of the event loop. For instance, executing all JavaScript code synchronously does not account for the asynchronous nature of JavaScript and would negate the need for an event loop. Handling DOM events is part of what JavaScript can do, but the event loop encompasses much more than just DOM event management. Lastly, switching between programming languages is not relevant in the context of how the event loop functions within JavaScript.