closure + protoype pattern

var sys = require('sys');

//use protoype methods for massive speed improvement (and less memory consumption)
function greetBehaviors(message) {
    this.message = message;
}
greetBehaviors.prototype.greet = function() {
    sys.puts(this.message);
};
greetBehaviors.prototype.slowGreet = function() {
    sys.puts(this.message);
};

// Define the factory (encapsulate private data while still using a single memory location for the functions)
function newPerson(name, age) {

  // Store the message in a closure
  var message = name + ", who is " + age + " years old, says hi!";

  return new greetBehaviors(message);
}

// Export the factory as a module, keeping a) the methods shared across instances and b) the actual "class" private to this file (in CommonJS land anyway)
module.exports = newPerson;