--- id: 5d79253358e8f646cbeb2bb0 title: Part 015 challengeType: 0 isBeta: true --- ## Description
Change the `"+"` in the call to `infixToFunction` to `fn`. `fn` is the operator that the user inputs (`+`, `-`, `*` or `/`) - we use `infixToFunction` to get the function that corresponds to it.
## Instructions
## Tests
```yml tests: - text: See description above for instructions. testString: assert(code.replace(/\s/g, "").includes('str.replace(regex,(match,arg1,fn,arg2)=>infixToFunction[fn])')); ```
## Challenge Seed
```html ```
### Before Test
```html Spreadsheet
```
### After Test
```html ```
## Solution
```html ```