npm package: @stdlib/symbol-is-concat-spreadable
Description: Concat spreadable symbol.
Author: The Stdlib Authors
Latest version: 0.1.1

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# IsConcatSpreadableSymbol

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

> Concat spreadable [symbol][mdn-symbol] which specifies whether an array-like object should be flattened to its array elements during concatenation.

<!-- 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/symbol-is-concat-spreadable
```

</section>

<section class="usage">

## Usage

```javascript
var IsConcatSpreadableSymbol = require( '@stdlib/symbol-is-concat-spreadable' );
```

#### IsConcatSpreadableSymbol

Concat spreadable [`symbol`][mdn-symbol] which specifies whether an array-like object should be flattened to its array elements during concatenation.

```javascript
var s = typeof IsConcatSpreadableSymbol;
// e.g., returns 'symbol'
```

</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

-   The [symbol][mdn-symbol] is only supported in environments which support [symbols][mdn-symbol]. In non-supporting environments, the value is `null`.

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

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

```javascript
var IsConcatSpreadableSymbol = require( '@stdlib/symbol-is-concat-spreadable' );

var x = [ 1, 2, 3 ];
var y = {
    'length': 3,
    '0': 4,
    '1': 5,
    '2': 6
};

y[ IsConcatSpreadableSymbol ] = true;
console.log( x.concat( y ) );

y[ IsConcatSpreadableSymbol ] = false;
console.log( x.concat( y ) );
```

</section>

<!-- /.examples -->

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* * *

## 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

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---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

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[stdlib]: https://github.com/stdlib-js/stdlib

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[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/symbol-is-concat-spreadable/tree/deno
[deno-readme]: https://github.com/stdlib-js/symbol-is-concat-spreadable/blob/deno/README.md
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[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/symbol-is-concat-spreadable/main/LICENSE

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

</section>

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