inheritedWritablePropertyNames

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

    Usage

    var inheritedWritablePropertyNames = require( '@stdlib/utils/inherited-writable-property-names' );
    

    inheritedWritablePropertyNames( obj[, level] )

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

    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 keys = inheritedWritablePropertyNames( 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 keys = inheritedWritablePropertyNames( 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 defineProperty = require( '@stdlib/utils/define-property' );
    var inheritedWritablePropertyNames = require( '@stdlib/utils/inherited-writable-property-names' );
    
    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 = inheritedWritablePropertyNames( obj );
    
    console.log( keys );
    // e.g., => [ 'foo', ... ]