Il web, l'universo e tutto quanto

JavaScript rule number one

Forget everything you know about OOP.

var mammal = {getName:function(){console.log("I am a mammal")}};

var Cat = function() {this.getName = function() {console.log("I am a cat")}};
Cat.prototype = mammal;

var Man = function() {this.getName = function() {console.log("I am a man")}}
Man.prototype = mammal;

luke = new Man();
luke.getName();

>>> I am a man

luke instanceof Cat
>>> true

If you are thinking “WTF???” you are wrong. JavaScript objects are decoupled from constructors and instanceof is just a unlucky naming to say something as simple as:

luke.__proto__ == Cat.prototype;