Test whether a string contains only white space characters.
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> Test whether a string contains only [white space][whitespace] characters.
``bash`
npm install @stdlib/assert-is-whitespace
`javascript`
var isWhitespace = require( '@stdlib/assert-is-whitespace' );
#### isWhitespace( value )
Tests whether a string contains only [white space][whitespace] characters.
`javascript`
var bool = isWhitespace( ' ' );
// returns true
- A [white space][whitespace] character is defined as one of the 25 characters defined as a [white space][whitespace] ("WSpace=Y","WS") character in the Unicode 9.0 character database, as well as one related [white space][whitespace] character without the Unicode character property "WSpace=Y" (zero width non-breaking space which was deprecated as of Unicode 3.2).
- For non-string values, the function returns false.
`javascript
var isWhitespace = require( '@stdlib/assert-is-whitespace' );
var out = isWhitespace( ' ' );
// returns true
out = isWhitespace( '' );
// returns false
out = isWhitespace( '\\r\\n' );
// returns false
out = isWhitespace( 123 );
// returns false
`
- [@stdlib/assert-is-whitespace-cli][@stdlib/assert-is-whitespace-cli]: CLI package for use as a command-line utility.
- [@stdlib/regexp-whitespace][@stdlib/regexp/whitespace]: return a regular expression to match a white space character.
*
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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/assert-is-whitespace-cli]: https://www.npmjs.com/package/@stdlib/assert-is-whitespace-cli
[npm-image]: http://img.shields.io/npm/v/@stdlib/assert-is-whitespace.svg
[npm-url]: https://npmjs.org/package/@stdlib/assert-is-whitespace
[test-image]: https://github.com/stdlib-js/assert-is-whitespace/actions/workflows/test.yml/badge.svg?branch=v0.2.3
[test-url]: https://github.com/stdlib-js/assert-is-whitespace/actions/workflows/test.yml?query=branch:v0.2.3
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/assert-is-whitespace/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/assert-is-whitespace?branch=main
[chat-image]: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg
[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/assert-is-whitespace#cli
[cli-url]: https://github.com/stdlib-js/assert-is-whitespace/tree/cli
[@stdlib/assert-is-whitespace]: https://github.com/stdlib-js/assert-is-whitespace/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-is-whitespace/tree/deno
[deno-readme]: https://github.com/stdlib-js/assert-is-whitespace/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/assert-is-whitespace/tree/umd
[umd-readme]: https://github.com/stdlib-js/assert-is-whitespace/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/assert-is-whitespace/tree/esm
[esm-readme]: https://github.com/stdlib-js/assert-is-whitespace/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/assert-is-whitespace/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/assert-is-whitespace/main/LICENSE
[whitespace]: https://en.wikipedia.org/wiki/Whitespace_character
[standard-streams]: https://en.wikipedia.org/wiki/Standard_streams
[mdn-regexp]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
[@stdlib/regexp/whitespace]: https://www.npmjs.com/package/@stdlib/regexp-whitespace