hasOwnProperty search for __proto__ ?
function Person(){}
Person.prototype.name = "Nicholas";
Person.prototype.age = 29;
Person.prototype.job = "Software Engineer";
Person.prototype.sayName = function(){
};
var person1 = new Person();
person1.hasOwnProperty("name") // false ?
the above example comes from Prefessional JavaScript for Web Developers
use chrome :
person1.hasOwnProperty("name") // is true