Constructor Function
function Person(){
this.name = "David",
this.greet = function(){
console.log("hello my name is " + this.name);
}
}
var person = new Person();
person.name = "johnny";
console.log(person);
var newPerson = new Person();
newPerson.name = "Sally";
var defaultPerson = new Person();
person.greet();
newPerson.greet();
defaultPerson.greet();