Handling optional parameters in javascript

Question

I have a static javascript function that can take 1, 2 or 3 parameters:

function getData(id, parameters, callback) //parameters (associative array) and callb         


        

Answer 1

This I guess may be self explanatory example:

function clickOn(elem /*bubble, cancelable*/) {
    var bubble =     (arguments.length > 1)  ? arguments[1] : true;
    var cancelable = (arguments.length == 3) ? arguments[2] : true;

    var cle = document.createEvent("MouseEvent");
    cle.initEvent("click", bubble, cancelable);
    elem.dispatchEvent(cle);
}