@stdlib/utils/property-symbols-in/README.md

Standard utilities.

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# propertySymbolsIn

> Return an array of an object's own and inherited [symbol][@stdlib/symbol/ctor] properties.

<section class="usage">

## Usage

```javascript
var propertySymbolsIn = require( '@stdlib/utils/property-symbols-in' );
```

#### propertySymbolsIn( obj )

Returns an `array` of an object's own and inherited [symbol][@stdlib/symbol/ctor] properties.

```javascript
var symbols = propertySymbolsIn( [] );
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   In contrast to the built-in `Object.getOwnPropertySymbols()`, if provided `null` or `undefined`, the function returns an empty `array`, rather than throwing an error.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var hasSymbolSupport = require( '@stdlib/assert/has-symbol-support' );
var Symbol = require( '@stdlib/symbol/ctor' );
var propertySymbolsIn = require( '@stdlib/utils/property-symbols-in' );

var hasSymbols = hasSymbolSupport();

function Foo() {
    if ( hasSymbols ) {
        this[ Symbol( 'beep' ) ] = 'boop';
    }
    return this;
}

if ( hasSymbols ) {
    Foo.prototype[ Symbol( 'foo' ) ] = 'bar';
}

var obj = new Foo();
var symbols = propertySymbolsIn( obj );

console.log( symbols );
```

</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/utils/property-names-in`][@stdlib/utils/property-names-in]</span><span class="delimiter">: </span><span class="description">return an array of an object's own and inherited enumerable and non-enumerable property names.</span>
-   <span class="package-name">[`@stdlib/utils/property-symbols`][@stdlib/utils/property-symbols]</span><span class="delimiter">: </span><span class="description">return an array of an object's own symbol properties.</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="links">

[@stdlib/symbol/ctor]: https://www.npmjs.com/package/@stdlib/symbol-ctor

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

[@stdlib/utils/property-names-in]: https://github.com/stdlib-js/utils/tree/main/property-names-in

[@stdlib/utils/property-symbols]: https://github.com/stdlib-js/utils/tree/main/property-symbols

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

</section>

<!-- /.links -->