const obj = [{ value: 1, elems: [ { value: 2, elems: [ { value: 3 }, { value: 6 }, ... ] }, { value: 4, elems: [ { value: 5, elems: [ { value: 6 }, ... ]} ] } ] }] ------------- setTimeout(() => { console.log(1); }, 0); const p = new Promise(resolve => { console.log(2); resolve(); }); p.then(() => { console.log(3) }).then(() => { console.log(4); }); console.log(5);

Let's consider the order of output to the console:

setTimeout(() => {
  console.log(1);
}, 0);

const p = new Promise(resolve => {
  console.log(2);
  resolve();
});

p.then(() => { console.log(3) }).then(() => { console.log(4); });

console.log(5);

Explanation:

• setTimeout places the callback in the macrotask queue with a delay of 0.
• When creating the promise, its executor runs immediately, so console.log(2) is output right away.
• p.then adds callbacks to the microtask queue.
• console.log(5) executes synchronously after the promise is created.

Output order:

1. 2 (immediately upon promise creation)
2. 5 (after the promise, synchronously)
3. 3 (microtask from then)
4. 4 (next microtask from the then chain)
5. 1 (macrotask from setTimeout)

Result:

2
5
3
4
1