Convert a string to constant case.
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> Convert a string to constant case.
``bash`
npm install @stdlib/string-constantcase
`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'
`
`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'
`
- [@stdlib/string-constantcase-cli][@stdlib/string-constantcase-cli]: CLI package for use as a command-line utility.
- [@stdlib/string-camelcase][@stdlib/string/camelcase]: convert a string to camel case.
- [@stdlib/string-kebabcase][@stdlib/string/kebabcase]: convert a string to kebab case.
- [@stdlib/string-pascalcase][@stdlib/string/pascalcase]: convert a string to Pascal case.
- [@stdlib/string-snakecase][@stdlib/string/snakecase]: convert a string to snake case.
*
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].
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---
See [LICENSE][stdlib-license].
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
[@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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[chat-url]: https://stdlib.zulipchat.com
[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
[@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