npm package: @stdlib/assert-has-utf16-surrogate-pair-at
Description: Test if a position in a string marks the start of a UTF-16 surrogate pair.
Author: The Stdlib Authors
Latest version: 0.2.3

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# hasUTF16SurrogatePairAt

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

> Test if a position in a string marks the start of a [UTF-16][utf-16] surrogate pair.

<section class="installation">

## Installation

```bash
npm install @stdlib/assert-has-utf16-surrogate-pair-at
```

</section>

<section class="usage">

## Usage

```javascript
var hasUTF16SurrogatePairAt = require( '@stdlib/assert-has-utf16-surrogate-pair-at' );
```

#### hasUTF16SurrogatePairAt( string, position )

Tests if a `position` (in [UTF-16][utf-16] code units) in a `string` marks the start of a [UTF-16][utf-16] surrogate pair.

```javascript
var bool = hasUTF16SurrogatePairAt( '🌷', 0 );
// returns true

bool = hasUTF16SurrogatePairAt( '🌷', 1 );
// returns false
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   Note that `position` does **not** refer to a visual character position, but to an index in the ordered sequence of [UTF-16][utf-16] code units.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var hasUTF16SurrogatePairAt = require( '@stdlib/assert-has-utf16-surrogate-pair-at' );

var bool = hasUTF16SurrogatePairAt( '🌷', 0 );
// returns true

bool = hasUTF16SurrogatePairAt( '🌷', 1 );
// returns false

```

</section>

<!-- /.examples -->



<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

## See Also

-   <span class="package-name">[`@stdlib/assert-has-utf16-surrogate-pair-at-cli`][@stdlib/assert-has-utf16-surrogate-pair-at-cli]</span><span class="delimiter">: </span><span class="description">CLI package for use as a command-line utility.</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].

</section>

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[@stdlib/assert-has-utf16-surrogate-pair-at-cli]: https://www.npmjs.com/package/@stdlib/assert-has-utf16-surrogate-pair-at-cli

[npm-image]: http://img.shields.io/npm/v/@stdlib/assert-has-utf16-surrogate-pair-at.svg
[npm-url]: https://npmjs.org/package/@stdlib/assert-has-utf16-surrogate-pair-at

[test-image]: https://github.com/stdlib-js/assert-has-utf16-surrogate-pair-at/actions/workflows/test.yml/badge.svg?branch=v0.2.3
[test-url]: https://github.com/stdlib-js/assert-has-utf16-surrogate-pair-at/actions/workflows/test.yml?query=branch:v0.2.3

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/assert-has-utf16-surrogate-pair-at/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/assert-has-utf16-surrogate-pair-at?branch=main

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[cli-section]: https://github.com/stdlib-js/assert-has-utf16-surrogate-pair-at#cli
[cli-url]: https://github.com/stdlib-js/assert-has-utf16-surrogate-pair-at/tree/cli
[@stdlib/assert-has-utf16-surrogate-pair-at]: https://github.com/stdlib-js/assert-has-utf16-surrogate-pair-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/assert-has-utf16-surrogate-pair-at/tree/deno
[deno-readme]: https://github.com/stdlib-js/assert-has-utf16-surrogate-pair-at/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/assert-has-utf16-surrogate-pair-at/tree/umd
[umd-readme]: https://github.com/stdlib-js/assert-has-utf16-surrogate-pair-at/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/assert-has-utf16-surrogate-pair-at/tree/esm
[esm-readme]: https://github.com/stdlib-js/assert-has-utf16-surrogate-pair-at/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/assert-has-utf16-surrogate-pair-at/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/assert-has-utf16-surrogate-pair-at/main/LICENSE

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

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

</section>

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