Self Documenting Flexible Parameters

Changing the number of Javascript function parameters can be unproductive because of the need to update other code calling that function whose parameters is changed. Greater chaos could occur if the work is done in teams. Addition or reduction of the number of Javascript function parameters must be communicated properly to prevent chaos. Updating code to adapt the API changes takes time and decreases productivity. So what is the solution to this problem? The solution is obviously to never add and reduce the number Javascript function parameter! Especially those functions decided as public interface.
So instead of doing this to define a public function:
function my_function(param1, param2, param3, param4, param5) {
utilize the Javascript object syntax and jQuery extend:
function my_function(params) {
        params = $.extend(true, {}, {
            param1: false,
            param2: null,
            param3: '',
            param4: function (a, b) {
                return (a < b);
            param5: null
        }, params);
Keep the number of parameter to one, that is the Javascript object containing attributes replacing function parameters. Although we change the parameters of the function with the object syntax, function interface remains easy to understand thanks to jQuery.extend. In fact we get added value with the ability to provide a default value and data type hint. The attributes whose values is the same with its default don't need to be passed to the function call. We just need to call the function as the example below which param1, param4, and param5 has the same values with its default:
    param2: "param2 value",
    param3: "param3 value"