writableProperties

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

Usage

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

writableProperties( obj )

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

var obj = {
    'a': 1,
    'b': 2
};

var props = writableProperties( obj );
// e.g., returns [ 'a', '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 writableProperties = require( '@stdlib/utils/writable-properties' );

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

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

Foo.prototype.c = 'c';
if ( hasSymbols ) {
    Foo.prototype[ Symbol( 'c' ) ] = 'c';
}

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

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