**The answer: from `0` to `4` in both cases.**

```js run
for (let i = 0; i < 5; ++i) alert( i );

for (let i = 0; i < 5; i++) alert( i );
```

That can be easily deducted from the algorithm of `for`:

1. Execute once `i = 0` before everything (begin).
2. Check the condition `i < 5`
3. If `true` -- execute the loop body `alert(i)`, and then `i++`

The increment `i++` is separated from the condition check (2). That's just another statement.

The value returned by the increment is not used here, so there's no difference between `i++` and `++i`.