sampleClass.js

// class
var Greeter = (function () {

	// constructor
	function Greeter(message) {

		// public variable
		this.greeting = message;

	}

	// public function
	Greeter.prototype.greet = function () {
		return _getHello.call(this);
	};

	// private static variable
	var _hello = "Hello";

	// private function
	function _getHello() {
		return _hello + ", " + this.greeting + "!";
	}

	return Greeter;
})();

var greeter = new Greeter("world");
var msg = greeter.greet(); // = "Hello, world!"
alert(msg);