nonEnumerableProperties

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

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', ... ]