Javascript Object Prototype Reference

Question

Javascript Object Prototype Reference

As per my knowledge, the second case below should be true, but in fact it is false. So why is it not true?

Case 1

     var P = function(){};
         P.prototype.get = function(){};

    var p = new P,q = new P;        
    console.log(q.__proto__ === p.__proto__) //true

Case 2

var PP = function(){
    var P = function(){};
    P.prototype.get = function(){};
    return new P;
};

var p = PP(), q = PP();
console.log(q.__proto__ === p.__proto__) //false

javascript
node.js
prototype

Answer 1

In the first case, P and get() are predefined globals. In the second, they're local to the function that defines PP, hence, a different reference for each instance.

Answer 2

In the top one, you have a new P.

In the second, you have new P in the function and then take new of that function.

This might screw it up.

Nevermind, it's because of the global vars, like he said.

Answer 3

In the first case var p = new P,q = new P; both instantiated the global P and it's prototype so it returns true.

In the second case q and p are both different objects instantiated using new PP which returned different P from inside PP function using return new P. So it returns false.

Answer 4

When you call the PP function you create a new function object each time that is called P. Each one of those functions has a different prototype.