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!

inheritedWritablePropertySymbols

Return an array of an object's inherited writable symbol properties.

Installation

npm install @stdlib/utils-inherited-writable-property-symbols

Alternatively,

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

The branches.md 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

var inheritedWritablePropertySymbols = require( '@stdlib/utils-inherited-writable-property-symbols' );

inheritedWritablePropertySymbols( obj[, level] )

Returns an array of an object's inherited writable symbol properties.

var defineProperty = require( '@stdlib/utils-define-property' );
var hasSymbolSupport = require( '@stdlib/assert-has-symbol-support' );
var Symbol = require( '@stdlib/symbol-ctor' );

var hasSymbols = hasSymbolSupport();
var symbols;
var f;

function Foo() {
    if ( hasSymbols ) {
        defineProperty( this, Symbol( 'a' ), {
            'configurable': false,
            'enumerable': false,
            'writable': true,
            'value': 'a'
        });
    }
    return this;
}

if ( hasSymbols ) {
    defineProperty( Foo.prototype, Symbol( 'b' ), {
        'configurable': false,
        'enumerable': false,
        'writable': true,
        'value': 'b'
    });
}

f = new Foo();
symbols = inheritedWritablePropertySymbols( f );

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

var symbols = inheritedWritablePropertySymbols( [], 1 );

Notes

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

Examples

var defineProperty = require( '@stdlib/utils-define-property' );
var hasSymbolSupport = require( '@stdlib/assert-has-symbol-support' );
var Symbol = require( '@stdlib/symbol-ctor' );
var inheritedWritablePropertySymbols = require( '@stdlib/utils-inherited-writable-property-symbols' );

var hasSymbols = hasSymbolSupport();
var symbols;
var obj;

function Foo() {
    this.a = 'a';
    defineProperty( this, 'b', {
        'configurable': false,
        'enumerable': false,
        'writable': false,
        'value': 'b'
    });
    if ( hasSymbols ) {
        this[ Symbol( 'a' ) ] = 'a';
        defineProperty( this, Symbol( 'b' ), {
            'configurable': false,
            'enumerable': false,
            'writable': false,
            'value': 'b'
        });
    }
    return this;
}

Foo.prototype.c = 'c';
defineProperty( Foo.prototype, 'd', {
    'configurable': false,
    'enumerable': false,
    'writable': false,
    'value': 'd'
});
if ( hasSymbols ) {
    Foo.prototype[ Symbol( 'c' ) ] = 'c';
    defineProperty( Foo.prototype, Symbol( 'd' ), {
        'configurable': false,
        'enumerable': false,
        'writable': false,
        'value': 'd'
    });
}

obj = new Foo();
symbols = inheritedWritablePropertySymbols( obj );

console.log( symbols );

---

See Also

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

---

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.