# What does this JavaScript closure log?

**URL:** <https://forum.kirupa.com/t/what-does-this-javascript-closure-log/679749>\
**Category:** web dev\
**Created:** [March 31, 2026, 9:00am UTC](https://forum.kirupa.com/t/what-does-this-javascript-closure-log/679749 "2026-03-31T09:00:07Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![sarah\_connor](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/sarah_connor/32/31258_2.png) [@sarah\_connor](https://forum.kirupa.com/u/sarah_connor)\
**Post date:** [March 31, 2026, 9:00am UTC](https://forum.kirupa.com/t/what-does-this-javascript-closure-log/679749/1 "2026-03-31T09:00:07Z")

</div>

Consider this snippet.

```javascript
for (var i = 0; i < 3; i++) {
  setTimeout(() => console.log(i), 0);
}

```

What gets logged, and what tiny change would make it log `0, 1, 2`.

Sarah

---

<div class="post-metadata">

**Author:** ![ArthurDent](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/arthurdent/32/31262_2.png) [@ArthurDent](https://forum.kirupa.com/u/ArthurDent)\
**Post date:** [March 31, 2026, 9:14am UTC](https://forum.kirupa.com/t/what-does-this-javascript-closure-log/679749/2 "2026-03-31T09:14:06Z")

</div>

It logs `3` three times because `var` shares one loop variable, and changing `var i` to `let i` gives each iteration its own binding so you get `0, 1, 2`.

Arthur