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

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# isNegativeNumber

[![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 a number having a negative value.

<section class="installation">

## Installation

```bash
npm install @stdlib/assert-is-negative-number
```

</section>

<section class="usage">

## Usage

```javascript
var isNegativeNumber = require( '@stdlib/assert-is-negative-number' );
```

#### isNegativeNumber( value )

Tests if a `value` is a `number` having a negative value.

<!-- eslint-disable no-new-wrappers -->

```javascript
var Number = require( '@stdlib/number-ctor' );

var bool = isNegativeNumber( -5.0 );
// returns true

bool = isNegativeNumber( new Number( -5.0 ) );
// returns true

bool = isNegativeNumber( -3.14 );
// returns true

bool = isNegativeNumber( 5.0 );
// returns false

bool = isNegativeNumber( null );
// returns false
```

#### isNegativeNumber.isPrimitive( value )

Tests if a `value` is a primitive `number` having a negative value.

<!-- eslint-disable no-new-wrappers -->

```javascript
var Number = require( '@stdlib/number-ctor' );

var bool = isNegativeNumber.isPrimitive( -3.0 );
// returns true

bool = isNegativeNumber.isPrimitive( new Number( -3.0 ) );
// returns false
```

#### isNegativeNumber.isObject( value )

Tests if a `value` is a `Number` object having a negative value.

<!-- eslint-disable no-new-wrappers -->

```javascript
var Number = require( '@stdlib/number-ctor' );

var bool = isNegativeNumber.isObject( -3.0 );
// returns false

bool = isNegativeNumber.isObject( new Number( -3.0 ) );
// returns true
```

</section>

<!-- /.usage -->

<section class="examples">

## Examples

<!-- eslint-disable no-new-wrappers -->

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

```javascript
var Number = require( '@stdlib/number-ctor' );
var isNegativeNumber = require( '@stdlib/assert-is-negative-number' );

var bool = isNegativeNumber( -5.0 );
// returns true

bool = isNegativeNumber( new Number( -5.0 ) );
// returns true

bool = isNegativeNumber( -3.14 );
// returns true

bool = isNegativeNumber( 0.0 );
// returns false

bool = isNegativeNumber( 5.0 );
// returns false

bool = isNegativeNumber( '-5' );
// returns false

bool = isNegativeNumber( null );
// 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-number`][@stdlib/assert/is-number]</span><span class="delimiter">: </span><span class="description">test if a value is a number.</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-negative-number.svg
[npm-url]: https://npmjs.org/package/@stdlib/assert-is-negative-number

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

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

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

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

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

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

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

</section>

<!-- /.links -->