inherited-writable-properties

inheritedWritableProperties

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

Usage

var inheritedWritableProperties = require( '@stdlib/utils/inherited-writable-properties' );

inheritedWritableProperties( obj[, level] )

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

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

function Foo() {
    this.a = 'b';
    return this;
}

defineProperty( Foo.prototype, 'beep', {
    'configurable': false,
    'enumerable': false,
    'writable': true,
    'value': 'boop'
});

var f = new Foo();
var props = inheritedWritableProperties( f );
// e.g., returns [ 'beep', ... ]

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

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

function Bar() {
    return this;
}

defineProperty( Bar.prototype, 'boop', {
    'configurable': false,
    'enumerable': false,
    'writable': true,
    'value': 'beep'
});

function Foo() {
    Bar.call( this );
    this.a = 'b';
    return this;
}

inherit( Foo, Bar );

defineProperty( Foo.prototype, 'beep', {
    'configurable': false,
    'enumerable': false,
    'writable': true,
    'value': 'boop'
});

var f = new Foo();
var pros = inheritedWritableProperties( f, 1 );
// e.g., returns [ 'beep', ... ]

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

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

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

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

obj = new Foo();
props = inheritedWritableProperties( obj );

console.log( props );
// e.g., => [ 'c', ... ]

---

See Also

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