@stdlib/utils-inherited-keys
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    0.0.6 • Public • Published

    inheritedKeys

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    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' ]

    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.

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    License

    See LICENSE.

    Copyright

    Copyright © 2016-2021. The Stdlib Authors.

    Install

    npm i @stdlib/utils-inherited-keys

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    7

    Version

    0.0.6

    License

    Apache-2.0

    Unpacked Size

    38.2 kB

    Total Files

    9

    Last publish

    Collaborators

    • stdlib-bot
    • kgryte
    • planeshifter
    • rreusser