--- id: 5d792538be4fe331f1a6c008 title: Part 104 challengeType: 0 isBeta: true --- ## Description
Unfortunately, impure functions are necessary - if you don't use them, the application won't perform any I/O so won't do anything. But we have an impure function that could be pure - `evalFormula`. It calls `document.getElementById(c + n).value`, but this value can change, even if the arguments don't. Change these calls to `""` - the function is now pure but doesn't work.
## Instructions
## Tests
```yml tests: - text: See description above for instructions. testString: const nos = code.replace(/\s/g, ""); assert(nos.includes('elemValue=n=>c=>""') && nos.includes('match=>""')) ```
## Challenge Seed
```html ```
### Before Test
```html Spreadsheet
```
### After Test
```html ```
## Solution
```html ```