The event loop is a critical part of JavaScript’s runtime, enabling asynchronous programming. Here’s a simple example:

console.log('Start');

setTimeout(() => {
    console.log('Timeout');
}, 0);

console.log('End');

Output:

Start
End
Timeout

The event loop ensures that the call stack is empty before executing tasks from the callback queue. This mechanism allows JavaScript to handle asynchronous operations efficiently.

node -e "console.log('Start'); setTimeout(() => { console.log('Timeout'); }, 0); console.log('End');"