JuniorTheoryCommon

What does the program print (lines separated by spaces)?

JavaScript

console.log(1);
setTimeout(() => {
    console.log(2);
}, 0);
Promise.resolve().then(() => {
    console.log(3);
});
console.log(4);

1 4 3 2

Expecting 1 4 2 3 because the timer was set first: a then callback runs before any setTimeout callback waiting at the same moment.
Expecting 3 before 4: even for a promise that is already fulfilled, then only schedules the callback, and it runs after the current code ends.

What does the program print if the setTimeout delay is 10 instead of 0?
What does the program print if a second .then printing 5 is chained after the first?

JuniorTheoryCommon

JavaScript

console.log(1);
setTimeout(() => {
    console.log(2);
}, 0);
Promise.resolve().then(() => {
    console.log(3);
});
console.log(4);

1 4 3 2

Expecting 1 4 2 3 because the timer was set first: a then callback runs before any setTimeout callback waiting at the same moment.
Expecting 3 before 4: even for a promise that is already fulfilled, then only schedules the callback, and it runs after the current code ends.

What does the program print if the setTimeout delay is 10 instead of 0?
What does the program print if a second .then printing 5 is chained after the first?