@stdlib/utils/writable-property-names/README.md

Standard utilities.

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# writablePropertyNames

> Return an array of an object's own writable property names.

<section class="usage">

## Usage

<!-- eslint-disable id-length -->

```javascript
var writablePropertyNames = require( '@stdlib/utils/writable-property-names' );
```

#### writablePropertyNames( obj )

Returns an `array` of an object's own writable property names.

```javascript
var defineProperty = require( '@stdlib/utils/define-property' );

var obj = {
    'a': 'b'
};

defineProperty( obj, 'c', {
    'configurable': true,
    'enumerable': true,
    'writable': false,
    'value': 'd'
});

var keys = writablePropertyNames( obj );
// returns [ 'a' ]
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   Name order is not guaranteed, as `object` key enumeration is not specified according to the [ECMAScript specification][ecma-262-for-in]. In practice, however, most engines use insertion order to sort an `object`'s keys, thus allowing for deterministic extraction.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

<!-- eslint-disable id-length -->

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

```javascript
var defineProperty = require( '@stdlib/utils/define-property' );
var writablePropertyNames = require( '@stdlib/utils/writable-property-names' );

function Foo() {
    this.a = {
        'b': 'c'
    };
    defineProperty( this, 'baz', {
        'configurable': true,
        'enumerable': true,
        'writable': false,
        'value': 'qux'
    });
    return this;
}

Foo.prototype.foo = [ 'bar' ];
defineProperty( Foo.prototype, 'bip', {
    'configurable': false,
    'enumerable': false,
    'writable': false,
    'value': 'bop'
});

var obj = new Foo();
var keys = writablePropertyNames( obj );

console.log( keys );
// => [ 'a' ]
```

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

[ecma-262-for-in]: https://262.ecma-international.org/5.1/#sec-12.6.4

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

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

[@stdlib/utils/writable-properties]: https://github.com/stdlib-js/utils/tree/main/writable-properties

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

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

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

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

</section>

<!-- /.links -->