nonEnumerableProperties

Return an array of an object's own non-enumerable property names and symbols.

Installation

npm install @stdlib/utils-nonenumerable-properties

Usage

var nonEnumerableProperties = require( '@stdlib/utils-nonenumerable-properties' );

nonEnumerableProperties( obj )

Returns an array of an object's own non-enumerable property names and symbols.

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

var obj = {};

obj.a = 'a';
defineProperty( obj, 'b', {
    'configurable': false,
    'enumerable': false,
    'writable': false,
    'value': 'b'
});

var props = nonEnumerableProperties( obj );
// returns [ 'b' ]

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 nonEnumerableProperties = require( '@stdlib/utils-nonenumerable-properties' );

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

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

console.log( props );
// => [ 'b', ... ]

See Also

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