writablePropertySymbols
Return an array of an object's own writable symbol properties.
Usage
var writablePropertySymbols = require( '@stdlib/utils/writable-property-symbols' );
writablePropertySymbols( obj )
Returns an array
of an object's own writable symbol properties.
var hasSymbolSupport = require( '@stdlib/assert/has-symbol-support' );
var Symbol = require( '@stdlib/symbol/ctor' );
var defineProperty = require( '@stdlib/utils/define-property' );
var obj = {};
if ( hasSymbolSupport() ) {
defineProperty( obj, Symbol( 'a' ), {
'configurable': false,
'enumerable': false,
'writable': true,
'value': 'b'
});
}
var symbols = writablePropertySymbols( obj );
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 anobject
's properties, thus allowing for deterministic extraction.
Examples
var hasSymbolSupport = require( '@stdlib/assert/has-symbol-support' );
var Symbol = require( '@stdlib/symbol/ctor' );
var writablePropertySymbols = require( '@stdlib/utils/writable-property-symbols' );
var hasSymbols = hasSymbolSupport();
function Foo() {
if ( hasSymbols ) {
this[ Symbol( 'baz' ) ] = 'qux';
}
return this;
}
if ( hasSymbols ) {
Foo.prototype[ Symbol( 'bip' ) ] = 'bop';
}
var obj = new Foo();
var symbols = writablePropertySymbols( obj );
// e.g., returns [ Symbol( 'baz' ) ]