22 lines
531 B
Markdown
22 lines
531 B
Markdown
---
|
|
title: Test if all array elements are falsy
|
|
type: snippet
|
|
tags: [array]
|
|
cover: bug
|
|
dateModified: 2020-10-21T21:54:53+03:00
|
|
---
|
|
|
|
Checks if the provided predicate function returns `false` for all elements in a collection.
|
|
|
|
- Use `Array.prototype.some()` to test if any elements in the collection return `true` based on `fn`.
|
|
- Omit the second argument, `fn`, to use `Boolean` as a default.
|
|
|
|
```js
|
|
const none = (arr, fn = Boolean) => !arr.some(fn);
|
|
```
|
|
|
|
```js
|
|
none([0, 1, 3, 0], x => x == 2); // true
|
|
none([0, 0, 0]); // true
|
|
```
|