npm package: @stdlib/assert-is-falsy
Description: Test if a value is falsy.
Author: The Stdlib Authors
Latest version: 0.2.3

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<details>
  <summary>
    About stdlib...
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# isFalsy

[![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 value is falsy.

<section class="installation">

## Installation

```bash
npm install @stdlib/assert-is-falsy
```

</section>

<section class="usage">

## Usage

```javascript
var isFalsy = require( '@stdlib/assert-is-falsy' );
```

#### isFalsy( value )

Tests if a `value` is a value which translates to `false` when evaluated in a boolean context.

```javascript
var bool = isFalsy( false );
// returns true

bool = isFalsy( '' );
// returns true

bool = isFalsy( 0 );
// returns true

bool = isFalsy( NaN );
// returns true

bool = isFalsy( null );
// returns true

bool = isFalsy( void 0 );
// returns true

bool = isFalsy( [] );
// returns false
```

</section>

<!-- /.usage -->

<section class="examples">

## Examples

<!-- eslint-disable no-empty-function, no-restricted-syntax -->

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

```javascript
var isFalsy = require( '@stdlib/assert-is-falsy' );

var bool = isFalsy( false );
// returns true

bool = isFalsy( 0 );
// returns true

bool = isFalsy( NaN );
// returns true

bool = isFalsy( '' );
// returns true

bool = isFalsy( void 0 );
// returns true

bool = isFalsy( null );
// returns true

bool = isFalsy( 'beep' );
// returns false

bool = isFalsy( 5 );
// returns false

bool = isFalsy( true );
// returns false

bool = isFalsy( [] );
// returns false

bool = isFalsy( {} );
// returns false

bool = isFalsy( function foo() {} );
// 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-is-falsy-array`][@stdlib/assert/is-falsy-array]</span><span class="delimiter">: </span><span class="description">test if a value is an array-like object containing only falsy values.</span>
-   <span class="package-name">[`@stdlib/assert-is-truthy`][@stdlib/assert/is-truthy]</span><span class="delimiter">: </span><span class="description">test if a value is truthy.</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 -->

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<section class="links">

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

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

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

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[chat-image]: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg
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[stdlib]: https://github.com/stdlib-js/stdlib

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

[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-falsy/tree/deno
[deno-readme]: https://github.com/stdlib-js/assert-is-falsy/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/assert-is-falsy/tree/umd
[umd-readme]: https://github.com/stdlib-js/assert-is-falsy/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/assert-is-falsy/tree/esm
[esm-readme]: https://github.com/stdlib-js/assert-is-falsy/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/assert-is-falsy/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/assert-is-falsy/main/LICENSE

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

[@stdlib/assert/is-falsy-array]: https://www.npmjs.com/package/@stdlib/assert-is-falsy-array

[@stdlib/assert/is-truthy]: https://www.npmjs.com/package/@stdlib/assert-is-truthy

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

</section>

<!-- /.links -->