How to create private variable accessible to Prototype function?

Question

I\'m trying to get a deeper hold on prototypal inheritance and class creation (I know, there are other ways, but for the purpose of this I\'m trying to grasp prototypes.) My

Answer 1

It can be easily achieved like this

function SharedPrivate(){
  var private = "secret";
  this.constructor.prototype.getP = function(){return private}
  this.constructor.prototype.setP = function(v){ private = v;}
}

var o1 = new SharedPrivate();
var o2 = new SharedPrivate();

console.log(o1.getP()); // secret
console.log(o2.getP()); // secret
o1.setP("Pentax Full Frame K1 is on sale..!");
console.log(o1.getP()); // Pentax Full Frame K1 is on sale..!
console.log(o2.getP()); // Pentax Full Frame K1 is on sale..!
o2.setP("And it's only for $1,795._");
console.log(o1.getP()); // And it's only for $1,795._

Obviously the key point is to create an access route to a private variable by utilizing a closure and then sharing this access point among the objects to be created. Utilizing the access point as a prototype of the objects to be created for natural sharing is the ideal case. Accordingly the same functionality can be achieved by utilizing the factory pattern and Object.create() as follows;

function SharedPrivate(){
var priv = "secret";
return {gp : function(){return priv},
        sp : function(v){priv = v}
       }
}
sharedProto = SharedPrivate(); // priv is now under closure to be shared
var p1 = Object.create(sharedProto); // sharedProto becomes o1.__proto__
var p2 = Object.create(sharedProto); // sharedProto becomes o2.__proto__

JavaScript prototypical structure is golden..!