How to pass variable by reference in javascript? Read data from ActiveX function which returns more than one value

Question

I have a ActiveX object which I want to use in the browser (javascript).
There is a function I want to call. Its prototype is:

function TOPOSFiscalPrinter.DirectIO(Command: Integer; var pData: Integer;
  var pString: WideString): Integer;

So, the function returns three values: result code, pData and pString;
In javascript the function does not update the variables pData and pString;

function test()
{
  var d=1, s="DIRECIO:";
  var code = opos.DirectIO(1024, d, s);

  alert(d); alert(s);
}

Variables d and s are not updated. They must be d=0 and s="ED123456";
How to read data from function which returns more than one value in javascript?

EDIT
Apparently, Javascript always passes parameters by value, never by reference.
Is there anything I can do to pass values by reference in Javascript, or I will have to change my design to only rely on parameters passed by value and on return values.

Answer 1

Primitive types, primarily strings/numbers/booleans are passed by value for efficiency purposes. Objects such as functions, objects, arrays and the like are passed by reference. You can create an object and pass it, eg { d:1, s:'directo' } and then change the values because you're passing a reference.