npm package: @stdlib/boolean-ctor
Description: Boolean constructor.
Author: The Stdlib Authors
Latest version: 0.2.3

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

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> [Boolean][mdn-boolean] constructor.

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/boolean-ctor
```

</section>

<section class="usage">

## Usage

```javascript
var Boolean = require( '@stdlib/boolean-ctor' );
```

#### Boolean( value )

Returns a `Boolean` object, which is an object wrapper for a primitive boolean value.

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

```javascript
var b = new Boolean( null );
// returns <Boolean>
```

When invoked without `new`, the function converts an input value to a primitive boolean value.

```javascript
var b = Boolean( null );
// returns false
```

* * *

### Methods

<a name="method-to-string"></a>

##### Boolean.prototype.toString()

Returns a string representation of the boolean value.

```javascript
var b = new Boolean( true );
var str = b.toString();
// returns 'true'
```

##### Boolean.prototype.valueOf()

Returns the primitive value of the boolean object.

```javascript
var b = new Boolean( true );
var val = b.valueOf();
// returns true

b = new Boolean();
val = b.valueOf();
// returns false
```

</section>

<!-- /.usage -->

<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

## Notes

-   When invoked without `new`,

    -   if provided `false`, `null`, `undefined`, `-0`, `0`, `NaN`, or an empty string, the function returns `false`.
    -   if provided any other value, including an empty object, an empty array, the string `'false'`, or a `Boolean` object (including a `Boolean` object whose value is `false`), the function returns `true`.

-   When invoked with `new`, the value of the returned `Boolean` object adheres to the same conversion semantics as when the constructor is invoked without `new`.

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

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

<!-- eslint-disable new-cap -->

```javascript
var format = require( '@stdlib/string-format' );
var Bool = require( '@stdlib/boolean-ctor' );

var values = [
    '5',
    5,
    0,
    NaN,
    true,
    false,
    null,
    void 0,
    [],
    {}
];

var i;
for ( i = 0; i < values.length; i++ ) {
    console.log( format( '%s => %s', JSON.stringify( values[ i ] ), ( Bool( values[ i ] ) ) ? 'true' : 'false' ) );
}
```

</section>

<!-- /.examples -->

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<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>

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

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

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/boolean-ctor/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/boolean-ctor?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/boolean-ctor/tree/deno
[deno-readme]: https://github.com/stdlib-js/boolean-ctor/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/boolean-ctor/tree/umd
[umd-readme]: https://github.com/stdlib-js/boolean-ctor/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/boolean-ctor/tree/esm
[esm-readme]: https://github.com/stdlib-js/boolean-ctor/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/boolean-ctor/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/boolean-ctor/main/LICENSE

[mdn-boolean]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean

</section>

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