Is setTimeout required?

Question

I have a question to async, await and setTimeout(). I thought, I use asynchron functions for slow processes. So I tried it with a large loop. On my Computer, it needs few second

Answer 1

The difference is that this is completely synchronous code:

return new Promise(resolve => {
    for (let i = 0; i < 4000000000; i++) {};
    resolve('Ready at ' + new Date().toLocaleTimeString('de'));
});

This statement will block the JavaScript thread and force it to wait until all of those 4 billion iterations have taken place. Then it will move on to the next statement. Since the console.log executes after this, it will not execute until that loop has finished.

That's why you are seeing a difference.