# Check if a cell is defined

**URL:** https://talk.observablehq.com/t/check-if-a-cell-is-defined/4351
**Category:** Uncategorized
**Created:** [December 17, 2020, 9:54pm UTC](https://talk.observablehq.com/t/check-if-a-cell-is-defined/4351 "2020-12-17T21:54:48Z")
**Posts on this page:** 1
**Showing post:** 3

<div class="post-metadata">

### Author: ![mootari](https://yyz2.discourse-cdn.com/flex030/user_avatar/talk.observablehq.com/mootari/32/581_2.png) [@mootari](https://talk.observablehq.com/u/mootari)
#### Post date: [December 17, 2020, 11:39pm UTC](https://talk.observablehq.com/t/check-if-a-cell-is-defined/4351/3 "2020-12-17T23:39:39Z")

</div>

I doubt that you’ll have much luck. Observable checks the required dependencies statically and constructs a wrapper around your cell code. If you don’t explicitely access a cell value, it won’t be available.

I’d recommend to add a debugger statement to any cell that contains references, and inspect the transpiled code in your browser’s dev tools.

* * *

If you want to go fully meta and experimental, have a look at

> **[Runtime](https://observablehq.com/d/e1c39d41e8e944b0)**
>
> Based on an idea by Bryan Gin-ge Chen (which he explores in his notebook Dirty tricks). Disclaimer: The documentation found in this notebook must not be taken as fact. It's meant to be a "best effort" to dissect Observable's runtime. Presumably, our...

This notebook is [based on a hack](https://observablehq.com/d/4e5230c1d38f7c0f) that @bgchen mentioned to me (👋) and of course absolutely not recommended.

---

_[View the full topic](https://talk.observablehq.com/t/check-if-a-cell-is-defined/4351)._