How to set up JavaScript namespace and classes properly?

Do neither of those things.

Make a javascript "class":

var MyClass = function () {    var privateVar; //private    var privateFn = function(){}; //private     this.someProperty = 5;  //public    this.anotherProperty = false;  //public    this.someFunction = function () {  //public        //do something    };};MyNamespace.MyClass = new MyClass();

One with static vars:

var MyClass = (function(){    var static_var; //static private var    var MyClass = function () {        var privateVar; //private        var privateFn = function(){}; //private         this.someProperty = 5;  //public        this.anotherProperty = false;  //public        this.someFunction = function () {  //public            //do something        };    };    return MyClass;})();MyNamespace.MyClass = new MyClass();

With a "constructor" (all of the examples have a "constructor", this one just has parameters to work with):

var MyClass = function (a, b c) {    //DO SOMETHING WITH a, b, c <--    var privateVar; //private    var privateFn = function(){}; //private     this.someProperty = 5;  //public    this.anotherProperty = false;  //public    this.someFunction = function () {  //public        //do something    };};MyNamespace.MyClass = new MyClass(1, 3, 4);

With all of the above you can do:

MyNamespace.MyClass.someFunction();

But you cannot do (from the outside):

MyNamespace.MyClass.privateFn(); //ERROR!

The first example is simply an Object literal - it cannot be instantiated and doesn't have private members. The second example has some incorrect syntax (var someProperty: 5 should be var someProperty = 5) but is using a closure to encapsulate internal private state within a self-invoking anonymous function.

The second approach looks better for encapsulating private members, but could be made more "Object-oriented" by making it an instantiable class:

MyNamespace.MyClass = function() { ... };MyNamespace.MyClass.prototype.someProperty = 'foo';

Then you can instantiate it with the 'new' keyword:

var aClass = new MyNamespace.MyClass();aClass.init(...);

I use the following syntax for the instantiable classes with namespace

 var MYNamespace = MYNamespace|| {}; MYNamespace.MyFirstClass = function (val) {        this.value = val;        this.getValue = function(){                          return this.value;                       };    }var myFirstInstance = new MYNamespace.MyFirstClass(46);alert(myFirstInstance.getValue());

jsfiddle: http://jsfiddle.net/rpaul/4dngxwb3/1/