22 lines
621 B
Markdown
22 lines
621 B
Markdown
---
|
|
title: Cross product of arrays
|
|
tags: array,math
|
|
expertise: intermediate
|
|
cover: blog_images/cup-of-orange.jpg
|
|
firstSeen: 2018-01-24T15:55:03+02:00
|
|
lastUpdated: 2020-10-22T20:24:44+03:00
|
|
---
|
|
|
|
Creates a new array out of the two supplied by creating each possible pair from the arrays.
|
|
|
|
- Use `Array.prototype.reduce()`, `Array.prototype.map()` and `Array.prototype.concat()` to produce every possible pair from the elements of the two arrays.
|
|
|
|
```js
|
|
const xProd = (a, b) =>
|
|
a.reduce((acc, x) => acc.concat(b.map(y => [x, y])), []);
|
|
```
|
|
|
|
```js
|
|
xProd([1, 2], ['a', 'b']); // [[1, 'a'], [1, 'b'], [2, 'a'], [2, 'b']]
|
|
```
|