clone.js

var util = require("util");

var clone = function(obj) {
  var f = function() { };
  f.prototype = obj;
  return new f;
};

var person = {
  name: "Person",
  greeting: "Hello, I'm",
  greet: function() {
    util.puts(this.greeting + " " + this.name);
  }
}

person.greet();

util.puts("---");

var david = clone(person);

david.name = "David";

person.greet();
david.greet();

util.puts("---");

var javid = clone(david);

javid.greeting = "Hola, soy";

person.greet();
david.greet();
javid.greet();