Calling the Add Method

addMethod.js

(function ($) {
    $.widget("custom.clicker", {

        // Default options.
        options: {
            startingValue: 0,
            _currentValue : 0
        },

        // _create and other methods to access properties ommitted ..

        add: function (val) {
            if (val === undefined) {
                this.options._currentValue++;
            } else {
                this.options._currentValue += val;
            }
        }
    });
}(jQuery));

callingTheAddMethod.js

myClicker.clicker("add");
myClicker.clicker("add", 5);