---
id: 5e302e8ce003129199103c79
title: Part 22
challengeType: 0
isHidden: true
---
## Description
Now let's simplify the `reduce()` callback function by refactoring it.
Essentially, the current callback function is `(accumulator, currentValue) => { return accumulator + currentValue }`. Since there's only one expression in the function body, we can omit the `{}`. Additionally, we can omit the `return` keyword since that is implicit when using arrow function syntax.
So the function can be simplified to just `(accumulator, currentValue) => accumulator + currentValue`.
Replace the current callback function argument in the `reduce()` function with the simplified callback function from above.
## Instructions
## Tests
```yml
tests:
- text: See description above for instructions.
testString: assert( code.replace(/\s/g, '').match(/reduce\(\(accumulator\,currentValue\)\=\>accumulator\+currentValue\,0\)/) );
```
## Challenge Seed
```html
```
### Before Test
### After Test
```html