https://github.com/niksy/array-string-at

Array/string `.at()` ponyfill.
https://github.com/niksy/array-string-at

Last synced: 2 months ago
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Array/string `.at()` ponyfill.

• Host: GitHub
• URL: https://github.com/niksy/array-string-at
• Owner: niksy
• License: mit
• Created: 2020-12-28T12:49:45.000Z (almost 4 years ago)
• Default Branch: master
• Last Pushed: 2023-02-08T09:59:33.000Z (almost 2 years ago)
• Last Synced: 2024-10-11T23:48:52.675Z (3 months ago)
• Language: JavaScript
• Size: 28.3 KB
• Stars: 3
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE.md

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README

        
# array-string-at

[![Build Status][ci-img]][ci]

[![Browser testing by BrowserStack][browserstack-img]][browserstack]

[Array/string `.at()`](https://github.com/tc39/proposal-relative-indexing-method)

[ponyfill](https://ponyfill.com).

> […] `at()`, that is on the prototype of the built-in indexable objects:

> `Array`, `String`, and `TypedArrays` objects. The method supports relative

> indexing from the end when passed a negative index.

## Install

```sh

npm install array-string-at --save

```

## Usage

```js

import at from 'array-string-at';

at('becky', 1); // e

at('becky', -2); // k

```

You can **use named export `preferNative` if you wish to use native

implementation if it’s available**. In all other cases, ponyfill will be used.

Beware of

[caveats](https://github.com/sindresorhus/ponyfill#user-content-ponyfill:~:text=Ponyfills%20should%20never%20use%20the%20native,between%20environments%2C%20which%20can%20cause%20bugs.)!

### Polyfill

```js

import at from 'array-string-at';

if (typeof String.prototype.at === 'undefined') {

	Object.defineProperty(String.prototype, 'at', {

		configurable: true,

		writable: true,

		value: function (index) {

			return at(this, index);

		}

	});

}

if (typeof Array.prototype.at === 'undefined') {

	Object.defineProperty(Array.prototype, 'at', {

		configurable: true,

		writable: true,

		value: function (index) {

			return at(this, index);

		}

	});

}

```

## API

### at(item, index)

Returns: `*`

Returns value at specified index. Supports relative indexing from the end when

passed a negative index.

#### item

Type: `string|Array|TypedArray`

Item to search.

#### index

Type: `number`

Relative index.

## Browser support

Tested in Chrome 72, Edge 15, Firefox 65 and should work in all modern browsers

([support based on Browserslist configuration](https://browserslist.dev/?q=bGFzdCAzIG1ham9yIHZlcnNpb25zLCBzaW5jZSAyMDE5LCBlZGdlID49IDE1LCBub3QgaWUgPiAw)).

## Test

Test suite is taken and modified from following packages:

-   [es-shims, string](https://github.com/es-shims/String.prototype.at/blob/main/test/tests.js)

-   [es-shims, array](https://github.com/es-shims/Array.prototype.at/blob/main/test/tests.js)

For automated tests, run `npm run test:automated` (append `:watch` for watcher

support).

## License

MIT © [Ivan Nikolić](http://ivannikolic.com)

[ci]: https://travis-ci.com/niksy/array-string-at

[ci-img]: https://travis-ci.com/niksy/array-string-at.svg?branch=master

[browserstack]: https://www.browserstack.com/

[browserstack-img]: https://img.shields.io/badge/browser%20testing-BrowserStack-informational?logo=data:image/svg+xml;base64,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