---
id: 5d792536504e68254fe02236
title: Part 64
challengeType: 0
isHidden: true
---
## Description
The technique we just used is called currying - instead of taking multiple arguments, a function takes a single argument and return another function, which also takes a single argument.
Define a new curried function, `addChars`, and set it equal to `c1 => c2 => c1 + c2`.
## Instructions
## Tests
```yml
tests:
- text: See description above for instructions.
testString: assert(code.replace(/\s/g, "").includes("constaddChars=c1=>c2=>c1+c2"));
```
## Challenge Seed
```html
```
### Before Test
### After Test
```html
```
## Solution