Best Practices in Implementing OOP JavaScript (Namespaces , Classes , Objects methods in JavaScript )

<script type="text/javascript" charset="utf-8">


    // Root Namespace
    var Namespace = {};

    // Create a Class
    Namespace.Class1 = function () { };

    // Pulic Methods
    Namespace.Class1.prototype.M1 = function () {
        alert("M1");
    };


    // Create a Class with variables and members
    Namespace.Class2 = function () {

        // Public Variable
        this.x = "Pubilic variable";

        // Private Variable
        var y = "private variable";


        // Call private method. Only Constructor can call it
        privateMethod();
      
        // Private Method
        function privateMethod() {
            // Can access private variable
            //Can not access public variable
            y = 5;
            
        }

        //Privilaged method. Can access both public and private
        // call publically
        this.privatePublicMethod = function () {
            // access public variable
            this.x = 10;
            
            // access private variable
            y = 15;

            // accessing private method
            privateMethod();
            
        };
    };

    // Pulic Method and access the Public variable
    Namespace.Class2.prototype.M2 = function () {
        alert(this.x);
    };


    Namespace.Class3 = function () { };
    Namespace.Class3.prototype = new Namespace.Class1();
    Namespace.Class3.prototype.M3 = function () {
        alert("M3");
    };



    //Usage
    var a = new Namespace.Class1();
    a.M1();


    var b = new Namespace.Class2();
    alert(b.x);
    b.M2();
    b.privatePublicMethod();


    var c = new Namespace.Class3();
    c.M1(); // Inherited form Class 1
    c.M3(); // Class 3 implementations

</script>