23 lines
636 B
Markdown
23 lines
636 B
Markdown
---
|
|
title: aperture
|
|
tags: array,intermediate
|
|
---
|
|
|
|
Returns an array of `n`-tuples of consecutive elements.
|
|
|
|
Use `Array.prototype.slice()` and `Array.prototype.map()` to create an array of appropriate length and populate it with `n`-tuples of consecutive elements from `arr`.
|
|
If `n` is greater than the length of `arr`, return an empty array.
|
|
|
|
```js
|
|
const aperture = (n, arr) =>
|
|
n > arr.length
|
|
? []
|
|
: arr.slice(n - 1).map((v, i) => [...arr.slice(i, i + n - 1), v]);
|
|
```
|
|
|
|
```js
|
|
R.aperture(2, [1, 2, 3, 4]); // [[1, 2], [2, 3], [3, 4]]
|
|
R.aperture(3, [1, 2, 3, 4]); // [[1, 2, 3], [2, 3, 4]]
|
|
R.aperture(5, [1, 2, 3, 4]); // []
|
|
```
|