@stdlib/utils-inherited-keys

About stdlib...

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

inheritedKeys

Return an array of an object's inherited enumerable property names.

Installation

npm install @stdlib/utils-inherited-keys

Usage

var inheritedKeys = require( '@stdlib/utils-inherited-keys' );

inheritedKeys( obj[, level] )

Returns an array of an object's inherited enumerable property names.

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

Foo.prototype.beep = 'boop';

var f = new Foo();
var keys = inheritedKeys( f );
// returns [ 'beep' ]

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

var inherit = require( '@stdlib/utils-inherit' );

function Bar() {
    return this;
}

Bar.prototype.boop = 'beep';

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

inherit( Foo, Bar );
Foo.prototype.beep = 'boop';

var f = new Foo();
var keys = inheritedKeys( f, 1 );
// returns [ 'beep' ]

Notes

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

Examples

var defineProperty = require( '@stdlib/utils-define-property' );
var inheritedKeys = require( '@stdlib/utils-inherited-keys' );

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 = inheritedKeys( obj );

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

---

See Also

• @stdlib/utils-keys: return an array of an object's own enumerable property names.
• @stdlib/utils-keys-in: return an array of an object's own and inherited enumerable property names.
• @stdlib/utils-inherited-property-names: return an array of an object's inherited enumerable and non-enumerable property names.
• @stdlib/utils-inherited-property-symbols: return an array of an object's inherited symbol properties.

---

Notice

This package is part of 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, see the main project repository.

Community

---

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.