npm package: @stdlib/string-constantcase
Description: Convert a string to constant case.
Author: The Stdlib Authors
Latest version: 0.2.3

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<details>
  <summary>
    About stdlib...
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  <p>We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.</p>
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# constantcase

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

> Convert a string to constant case.

<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/string-constantcase
```

</section>

<section class="usage">

## Usage

```javascript
var constantcase = require( '@stdlib/string-constantcase' );
```

#### constantcase( str )

Converts a string to constant case.

```javascript
var str = constantcase( 'foo bar' );
// returns 'FOO_BAR'

str = constantcase( 'foo bar baz' );
// returns 'FOO_BAR_BAZ'

str = constantcase( 'foo_bar' );
// returns 'FOO_BAR'
```

</section>

<!-- /.usage -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

```javascript
var constantcase = require( '@stdlib/string-constantcase' );

var str = 'Hello World!';
var out = constantcase( str );
// returns 'HELLO_WORLD'

str = 'I am a tiny little teapot';
out = constantcase( str );
// returns 'I_AM_A_TINY_LITTLE_TEAPOT'

str = 'with big problems';
out = constantcase( str );
// returns 'WITH_BIG_PROBLEMS'

str = 'To be, or not to be: that is the question.';
out = constantcase( str );
// returns 'TO_BE_OR_NOT_TO_BE_THAT_IS_THE_QUESTION'

str = 'isMobile';
out = constantcase( str );
// returns 'IS_MOBILE'
```

</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/string-constantcase-cli`][@stdlib/string-constantcase-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-camelcase`][@stdlib/string/camelcase]</span><span class="delimiter">: </span><span class="description">convert a string to camel case.</span>
-   <span class="package-name">[`@stdlib/string-kebabcase`][@stdlib/string/kebabcase]</span><span class="delimiter">: </span><span class="description">convert a string to kebab case.</span>
-   <span class="package-name">[`@stdlib/string-pascalcase`][@stdlib/string/pascalcase]</span><span class="delimiter">: </span><span class="description">convert a string to Pascal case.</span>
-   <span class="package-name">[`@stdlib/string-snakecase`][@stdlib/string/snakecase]</span><span class="delimiter">: </span><span class="description">convert a string to snake case.</span>

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->


<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>

<!-- /.stdlib -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

[@stdlib/string-constantcase-cli]: https://www.npmjs.com/package/@stdlib/string-constantcase-cli

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

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

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

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

[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors

[cli-section]: https://github.com/stdlib-js/string-constantcase#cli
[cli-url]: https://github.com/stdlib-js/string-constantcase/tree/cli
[@stdlib/string-constantcase]: https://github.com/stdlib-js/string-constantcase/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-constantcase/tree/deno
[deno-readme]: https://github.com/stdlib-js/string-constantcase/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/string-constantcase/tree/umd
[umd-readme]: https://github.com/stdlib-js/string-constantcase/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/string-constantcase/tree/esm
[esm-readme]: https://github.com/stdlib-js/string-constantcase/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/string-constantcase/blob/main/branches.md

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

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

[mdn-regexp]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions

<!-- <related-links> -->

[@stdlib/string/camelcase]: https://www.npmjs.com/package/@stdlib/string-camelcase

[@stdlib/string/kebabcase]: https://www.npmjs.com/package/@stdlib/string-kebabcase

[@stdlib/string/pascalcase]: https://www.npmjs.com/package/@stdlib/string-pascalcase

[@stdlib/string/snakecase]: https://www.npmjs.com/package/@stdlib/string-snakecase

<!-- </related-links> -->

</section>

<!-- /.links -->