---
id: 5d7925383f1b77db7f1ff59e
title: Step 100
challengeType: 0
isBeta: true
---
## Description
This is (probably) false, so `random` is certainly impure.
The second property of pure functions is that they perform no side effects, which are state and I/O modifications.
If you call a function without assigning the result to a variable, and it does something, then it's an impure function.
Call `window.onload()` in `update`.
## Instructions
## Tests
```yml
tests:
- text: See description above for instructions.
testString: assert(/update=\(?event\)?=>\{.*window\.onload\(\).*\}/.test(code.replace(/\s/g, "")));
```
## Challenge Seed
```html
```
### Before Test
### After Test
```html
```
## Solution