npm package: @stdlib/string-code-point-at
Description: Return a Unicode code point from a string at a specified position.
Author: The Stdlib Authors
Latest version: 0.2.3

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# codePointAt

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Return a Unicode [code point][code-point] from a string at a specified position.

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<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/string-code-point-at
```

</section>

<section class="usage">

## Usage

```javascript
var codePointAt = require( '@stdlib/string-code-point-at' );
```

#### codePointAt( string, position\[, backward] )

Returns a Unicode [code point][code-point] from a string at a specified position.

```javascript
var out = codePointAt( 'last man standing', 4 );
// returns 32
```

The function supports providing a `backward` argument for performing backward iteration for low surrogates.

```javascript
var out = codePointAt( '🌷', 1, true );
// returns 127799
```

The function supports providing a negative `position`.

```javascript
var out = codePointAt( 'last man standing', -13 );
// returns 32
```

</section>

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<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

## Notes

This function differs from [`String.prototype.codePointAt`][mdn-string-codepointat] in the following ways:

-   The function supports providing a negative `position`. If provided a negative `position`, the function determines the string position relative to the end of the string.
-   The function supports providing a `backward` argument for performing backward iteration for low surrogates. [`String.prototype.codePointAt`][mdn-string-codepointat] simply returns the low surrogate value if no [UTF-16][utf-16] surrogate pair begins at the specified position. If invoked with `backward` set to `true`, this function will return the code point after aggregating with the preceding high surrogate, if the specified position does not mark the start of a surrogate pair.
-   The function raises an exception if provided a `position` which exceeds the bounds of the input string.

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var codePointAt = require( '@stdlib/string-code-point-at' );

var v = codePointAt( 'last man standing', 4 );
// returns 32

v = codePointAt( 'presidential election', 8, true );
// returns 116

v = codePointAt( 'अनुच्छेद', 2 );
// returns 2369

v = codePointAt( '🌷', 1, true );
// returns 127799
```

</section>

<!-- /.examples -->

<!-- Section for describing a command-line interface. -->



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<section class="related">

## See Also

-   <span class="package-name">[`@stdlib/string-code-point-at-cli`][@stdlib/string-code-point-at-cli]</span><span class="delimiter">: </span><span class="description">CLI package for use as a command-line utility.</span>
-   <span class="package-name">[`@stdlib/string-from-code-point`][@stdlib/string/from-code-point]</span><span class="delimiter">: </span><span class="description">create a string from a sequence of Unicode code points.</span>

</section>

<!-- /.related -->

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<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

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[@stdlib/string-code-point-at-cli]: https://www.npmjs.com/package/@stdlib/string-code-point-at-cli

[npm-image]: http://img.shields.io/npm/v/@stdlib/string-code-point-at.svg
[npm-url]: https://npmjs.org/package/@stdlib/string-code-point-at

[test-image]: https://github.com/stdlib-js/string-code-point-at/actions/workflows/test.yml/badge.svg?branch=v0.2.3
[test-url]: https://github.com/stdlib-js/string-code-point-at/actions/workflows/test.yml?query=branch:v0.2.3

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/string-code-point-at/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/string-code-point-at?branch=main

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[stdlib]: https://github.com/stdlib-js/stdlib

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[cli-section]: https://github.com/stdlib-js/string-code-point-at#cli
[cli-url]: https://github.com/stdlib-js/string-code-point-at/tree/cli
[@stdlib/string-code-point-at]: https://github.com/stdlib-js/string-code-point-at/tree/main

[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/string-code-point-at/tree/deno
[deno-readme]: https://github.com/stdlib-js/string-code-point-at/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/string-code-point-at/tree/umd
[umd-readme]: https://github.com/stdlib-js/string-code-point-at/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/string-code-point-at/tree/esm
[esm-readme]: https://github.com/stdlib-js/string-code-point-at/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/string-code-point-at/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/string-code-point-at/main/LICENSE

[code-point]: https://en.wikipedia.org/wiki/Code_point

[standard-streams]: https://en.wikipedia.org/wiki/Standard_streams

[mdn-string-codepointat]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/codePointAt

[utf-16]: https://en.wikipedia.org/wiki/UTF-16

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[@stdlib/string/from-code-point]: https://www.npmjs.com/package/@stdlib/string-from-code-point

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