---
id: 5e302e8ce003129199103c79
title: Step 22
challengeType: 0
dashedName: step-22
---
# --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.
# --hints--
See description above for instructions.
```js
assert(
code
.replace(/\s/g, '')
.match(
/reduce\(\(accumulator\,currentValue\)\=\>accumulator\+currentValue\,0\)/
)
);
```
# --seed--
## --before-user-code--
```html