prototypes-are-references.js

'use strict';

// define a note constructor
function Note(name, content){
  this.name = name;
  this.content = content;
}

// add a print method to the note constructor's prototype
Note.prototype.print = function(){
  console.log(this.content);
};

function Reminder(name, content, time){
  // inherrit Note's properties
  Note.call(this, name, content);
  this.time = time;
}
// inherrit Note's methods, but still have unique prototype
Reminder.prototype = Object.create(Note.prototype);

// instantiant note a
var a = new Note('a', 'test a');
// instantiant reminder b
var b = new Reminder('b', 'test b', new Date());

// invoke the print method on notes a and b
a.print(); // test a 
b.print(); // test b

// change Note's prototype's print method
Note.prototype.print = function(){
  console.log('lul');
};

// changing Notes's prototype's print method also changed the print methods on a's and b's prototype
a.print(); // lul
b.print(); // lul

// change b's proto's proto's print method
b.__proto__.__proto__.print = function(){
  console.log('wat');
};

a.print(); // wat
b.print(); // wat

// change a's proto's print method 
a.__proto__.print = function(){
  console.log('duuuh');
};

// changing a's proto's print changes a's and b's print method
a.print(); // duuuh
b.print(); // duuuh

// change Reminders protoytpe's print method
Reminder.prototype.print = function(){
  console.log(this.content + '!!!!!!');
};

// changing Reminders prototype only changes b's
a.print(); // wat
b.print(); // test b!!!!!!

b.__proto__.print = function(){ 
  console.log("wat wat");
};

// changing b's proto's print only changes b's 
a.print(); // duuuh
b.print(); // wat wat