# isError
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> Test if a value is an [Error][mdn-error] object.
## Installation
```bash
npm install @stdlib/assert-is-error
```
## Usage
```javascript
var isError = require( '@stdlib/assert-is-error' );
```
#### isError( value )
Tests if a `value` is an [`Error`][mdn-error] object.
```javascript
var bool = isError( new Error( 'beep' ) );
// returns true
```
## Examples
```javascript
var isError = require( '@stdlib/assert-is-error' );
var bool = isError( new Error( 'error' ) );
// returns true
bool = isError( new EvalError( 'eval error' ) );
// returns true
bool = isError( new RangeError( 'range error' ) );
// returns true
bool = isError( new ReferenceError( 'reference error' ) );
// returns true
bool = isError( new SyntaxError( 'syntax error' ) );
// returns true
bool = isError( new TypeError( 'type error' ) );
// returns true
bool = isError( new URIError( 'URI error' ) );
// returns true
bool = isError( {} );
// returns false
bool = isError( null );
// returns false
```
* * *
## 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 © 2016-2022. The Stdlib [Authors][stdlib-authors].
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[npm-url]: https://npmjs.org/package/@stdlib/assert-is-error
[test-image]: https://github.com/stdlib-js/assert-is-error/actions/workflows/test.yml/badge.svg
[test-url]: https://github.com/stdlib-js/assert-is-error/actions/workflows/test.yml
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[coverage-url]: https://codecov.io/github/stdlib-js/assert-is-error?branch=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-error/tree/deno
[umd-url]: https://github.com/stdlib-js/assert-is-error/tree/umd
[esm-url]: https://github.com/stdlib-js/assert-is-error/tree/esm
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[chat-url]: https://gitter.im/stdlib-js/stdlib/
[stdlib]: https://github.com/stdlib-js/stdlib
[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/assert-is-error/main/LICENSE
[mdn-error]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error