writablePropertyNamesIn

Return an array of an object's own and inherited writable property names.

Usage

var writablePropertyNamesIn = require( '@stdlib/utils/writable-property-names-in' );

writablePropertyNamesIn( obj )

Returns an array of an object's own and inherited writable property names.

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

var obj = {
    'a': 'b'
};

defineProperty( obj, 'c', {
    'configurable': true,
    'enumerable': true,
    'writable': false,
    'value': 'd'
});

var keys = writablePropertyNamesIn( obj );
// e.g., returns [ 'a', ... ]

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 writablePropertyNamesIn = require( '@stdlib/utils/writable-property-names-in' );

function Foo() {
    this.a = {
        'b': 'c'
    };
    defineProperty( this, 'baz', {
        'configurable': true,
        'enumerable': true,
        'writable': false,
        'value': 'qux'
    });
    return this;
}

Foo.prototype.foo = [ 'bar' ];
defineProperty( Foo.prototype, 'bip', {
    'configurable': true,
    'enumerable': true,
    'writable': false,
    'value': 'bop'
});

var obj = new Foo();
var keys = writablePropertyNamesIn( obj );

console.log( keys );
// e.g., => [ 'a', 'foo', ... ]