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inheritedNonEnumerablePropertyNames

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

Return an array of an object’s inherited non-enumerable property names.

## Installation

bash
npm install @stdlib/utils-inherited-nonenumerable-property-names

Alternatively,

- To load the package in a website via a script tag without installation and bundlers, use the [ES Module][es-module] available on the [esm][esm-url] branch (see [README][esm-readme]).
- If you are using Deno, visit the [deno][deno-url] branch (see [README][deno-readme] for usage intructions).
- For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [umd][umd-url] branch (see [README][umd-readme]).

The [branches.md][branches-url] file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

## Usage

javascript
var inheritedNonEnumerablePropertyNames = require( '@stdlib/utils-inherited-nonenumerable-property-names' );

#### inheritedNonEnumerablePropertyNames( obj[, level] )

Returns an array of an object’s inherited non-enumerable property names.

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

function Foo() {
    this.a = 'b';
    return this;
}

defineProperty( Foo.prototype, 'beep', {
    'configurable': false,
    'enumerable': false,
    'writable': false,
    'value': 'boop'
});

var f = new Foo();
var keys = inheritedNonEnumerablePropertyNames( f );
// e.g., returns [ 'beep', ... ]

By default, the function walks an object’s entire prototype chain. To limit the inheritance level, provide a level argument.

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

function Bar() {
    return this;
}

defineProperty( Bar.prototype, 'boop', {
    'configurable': false,
    'enumerable': false,
    'writable': false,
    'value': 'beep'
});

function Foo() {
    Bar.call( this );
    this.a = 'b';
    return this;
}

inherit( Foo, Bar );

defineProperty( Foo.prototype, 'beep', {
    'configurable': false,
    'enumerable': false,
    'writable': false,
    'value': 'boop'
});

var f = new Foo();
var keys = inheritedNonEnumerablePropertyNames( f, 1 );
// e.g., returns [ 'beep', ... ]

## 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.

## Examples

javascript
var defineProperty = require( '@stdlib/utils-define-property' );
var inheritedNonEnumerablePropertyNames = require( '@stdlib/utils-inherited-nonenumerable-property-names' );

function Foo() {
    this.beep = 'boop';
    this.a = {
        'b': 'c'
    };
    defineProperty( this, 'baz', {
        'configurable': false,
        'enumerable': false,
        'writable': true,
        '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 = inheritedNonEnumerablePropertyNames( obj );

console.log( keys );
// e.g., => [ 'bip', ... ]

*

## 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 © 2016-2024. The Stdlib [Authors][stdlib-authors].