javascript event loop

1const first = () => console.log('Hi,i am first');
2const second = () => console.log('Hi,i am second');
3const third = () => console.log('Hi,i am third');
4const fourth = () => {
5    first();
6    setTimeout(second, 4000);
7    //store in queue & it will execute after 4 seconds
8    setTimeout(third, 2000);
9    //store in queue & it will execute after 2 seconds
10    console.log('Hi,i am fourth');
11};
12fourth();
13
14//Expected output:
15/*Hi,i am first
16  Hi,i am fourth
17  Hi,i am third
18  Hi,i am second 
19*/

1         function task(message) {
2    // emulate time consuming task
3    let n = 10000000000;
4    while (n > 0){
5        n--;
6    }
7    console.log(message);
8}
9
10console.log('Start script...');
11task('Download a file.');
12console.log('Done!');
13Code language: JavaScript (javascript)