19 lines
442 B
Markdown
19 lines
442 B
Markdown
---
|
|
title: allUnique
|
|
tags: array,beginner
|
|
---
|
|
|
|
Checks if all elements in an array are unique.
|
|
|
|
- Create a new `Set` from the mapped values to keep only unique occurrences.
|
|
- Use `Array.prototype.length` and `Set.prototype.size` to compare the length of the unique values to the original array.
|
|
|
|
```js
|
|
const allUnique = arr => arr.length === new Set(arr).size;
|
|
```
|
|
|
|
```js
|
|
allUnique([1, 2, 3, 4]); // true
|
|
allUnique([1, 1, 2, 3]); // false
|
|
```
|