Question

I am getting a page() is not defined error message from Firebug with the following Javascript. Why?

( function() {
    var page = function() {
        var min_central_width = 10;
        function minimumCentralWidth(val) {
            min_central_width = val;
        }
    }

    $(document).ready(function() {
        page().minimumCentralWidth(400);
    });

})();

I am still new to Javascript. How can I avoid this?

Answer 1

The problem is that page isn’t returning a value, so page() is undefined. You would have to write something like this:

( function() {
    var page = function() {
        // create an object to return:
        var ret = {};
        // set its properties:
        ret.min_central_width = 10;
        ret.minimumCentralWidth =
            function (val) {
                this.min_central_width = val;
            };
        // return it:
        return ret;
    };

    $(document).ready(function() {
        page().minimumCentralWidth(400);
    });

})();

. . . but the above doesn’t really do anything. It creates a new object, and sets the object’s min_central_width to 400 . . . but it doesn’t use the object for anything, so the above doesn’t have any meaningful effect. (Is this just because you removed code that wasn’t relevant to the question? If so, then never mind. 🙂