---
title: juxt
tags: array,function,advanced
---

Takes several functions as argument and returns a function that is the juxtaposition of those functions. 

- Use `Array.prototype.map()` to return a `fn` that can take a variable number of `args`. 
- When `fn` is called, return an array containing the result of applying each `fn` to the `args`. 

```js
const juxt = (...fns) => (...args) => [...fns].map(fn => [...args].map(fn));
```

```js
juxt(
  x => x + 1,
  x => x - 1,
  x => x * 10
)(1, 2, 3); // [[2,3,4],[0,1,2],[10,20,30]]

juxt(
  s => s.length,
  s => s.split(" ").join("-")
)("30 seconds of code"); // [[18],['30-seconds-of-code']]
```
