Can't access to my namespace in a function

Question

I am doing a school assignement where we have to do a small application which manage a monster by following a pattern but my lesson is very badly explained so I understand nothing, I can't make the difference between public and private, I know what is the difference in Java, Php but not in js.

Here is what it does, when I load the page, it execute run() in monster.modules.app and this should execute showMe() in monster.modules.actions, the problem is I get this TypeError: monster.modules is undefined..

So can you explained me why I can't access to monster in this public or private function ?

And why do I have to put functions into parenthesis ?

(function (glob) {

    /**
     * Etape 1.1
     */
    // NAMESPACE : monster
    var monster = monster || {
            modules: {}
        };

    /**
     * Etape 1.2
     */
    monster.modules.actions = (function () {
        /**
         * Etape 1.2.1
         */
        var name;
        var life;
        var money;
        var awake;

        return {
            /**
             * Etape 1.2.2
             */
            showMe: function () {
                alert('Monster ' + this.name + ' : {life : ' + this.life + ', money : ' + this.money + ', awake : ' + this.awake + ' }');
            },

            /**
             * Etape 1.2.3
             */
            init: function (name, life, money, awake) {
                this.name = name;
                this.life = life;
                this.money = money;
                this.awake = awake;
            }
        };

    })();

    /**
     * Etape 1.3
     */
    monster.modules.app = (function () {
        /**
         * Etape 1.3.1
         */
        var show = document.getElementById('b6');

        return {
            /**
             * Etape 1.3.2
             */
            run: (function () {
                console.log('run');
                show.onclick = (function () {
                    monster.modules.actions.showMe();
                });

            })
        };
    })();

    /**
     * Etape 1.3.4
     */
    window.onload = (function () {
        monster.modules.app.run();
    });


})(window);

Where does the code snippet come from? Did you write it? To answer to your last question : as far as I understand, the function do not need to be surrounded by parenthesis. — C.Champagne, Feb 03 '16 at 11:07
*My lesson is very badly explained so I understand nothing.* So, never your fault, huh? — Frédéric Hamidi, Feb 03 '16 at 11:07
There is no "public" and "private" in JS, there are just variables (with a scope) and properties (that belong to an object). You might want to take a look [here](http://stackoverflow.com/a/13418980/1048572) — Bergi, Feb 03 '16 at 11:10
@C.Champagne I wrote it by folowing the exemple of my courses — oktomus, Feb 03 '16 at 11:55
@Bergi Thank you i didn't know that, the thing that disturbs me is the return that return functions, it's like a class isn't it ? — oktomus, Feb 03 '16 at 11:56
@georg The problem came out when i click on a button with the id b6 — oktomus, Feb 03 '16 at 11:57

Webastronaut · Accepted Answer · 2016-02-03T20:01:40.450

1

Actually you don't wrap every function in parenthesis like this

myIIF = (function { ... });

You can put them in parenthesis if you invoke them immediately, this type of function is called Immediately Invoked Functions or IIF:

myIIF = (function { ... })();

By invoking functions that way you create a so called closure, a function within a function to create a new scope.

You can find a straighforward explanation of closures here

edited Feb 03 '16 at 20:01

answered Feb 03 '16 at 11:17

Webastronaut

56
7

Thank you, I didn't understand that :) – oktomus Feb 03 '16 at 11:54
It is a detail but you don't need parenthesis for IIF: you could write directly `myIIF = function { ... }();` – C.Champagne Feb 03 '16 at 14:19

Can't access to my namespace in a function

1 Answers1