Constructor functions and their empty prototypes and adding functions to those prototypes in javascript

/* 
Finding the type of Object in js. Object is of type function in js and not of type Object. 
Object is a constructor function in js. 
*/
console.log(typeof Object);//function
//****************************************************************************************
var Employee = function (name, boss) {
 this.name = name;
  this.boss = boss;
};
var newEmployee = new Employee('jj', 'jhon jhones');
console.log(typeof newEmployee);//object
console.log(newEmployee.name);//jj
console.log(newEmployee.boss);//jhon jhones
//****************************************************************************************
var Employee = function(name){
 this.name = name;
};
var e1 = new Employee('jj');
var e2 = new Employee('kk');
var e3 = e1;
console.log(e1 == e2);//false
console.log( e1 === e2);//false
console.log(e1 == e3);//true
console.log( e1 === e3);//true
//****************************************************************************************
//__ double underscore is called dunder proto and is a kind of hack to enable us to reach the prototype 
console.log(e1.__proto__ === e2.__proto__);//true
/* The line above proves that both the employee objects have the same prototype and that
makes it very easy for the programmer to add functionalities to the Employee. We don't have
to write a function for the thousand of employee objects instead we just write it once
in the prototype of our Employee and all ojbects have acess to it.
*/
//****************************************************************************************
/* We should not add function to the body of the constructor Employee otherwise it would 
be duplicated into the body of all those objects that we are creating using this 
constructor. The following block of code is wrong. */
var Employee = function (name){
 this.name = name;
  this.giveRaise = function(){
   //Increase the salary by 10 %.
  };
};
var e1 = new Employee('jj');
var e2 = new Employee('kk');
console.log(e1.giveRaise === e2.giveRaise);//false
/* The line above gives false as both e1 and e2 get their own copies of function giveRaise() when
they are created using the constructor Employee. *
/* The correct way to do it is to add the function giveRaise to the prototype of the Employee constructor. See later in the code. */
//****************************************************************************************
/* When we work with json objects, we do not have direct access to the prototypes but 
now when we are working with the Constructor functions we do have access to the prototype. */
console.log(typeof Employee.prototype);//object
//****************************************************************************************
//Is Employee.prototype is the same as Object.prototype?
console.log(Employee.prototype === Object.prototype);//false
/* The line above gives false and that proves that Employee has got its own empty prototype
object. In json, each object has its prototype set to Object.prototype but that is not
the case when we are dealing with constructor functions. */
//****************************************************************************************
/* The correct way to add a funciton is not to add it to body of the constructor Employee
as done above in the code but to add it to the prototype of the connstructor Employee as 
shown below: */
var Employee = function (name){
 this.name = name;
  this.salary = 25000;//All employees get a start salary of 25 k during creation of an object of type Employee
};
Employee.prototype.giveRaise = function(raise){
 this.salary += raise;
};
var e1 = new Employee('jj');
var e2 = new Employee('kk');
console.log(e1.giveRaise === e2.giveRaise);//true
/* Now even if we 50 k employees we don't duplicate the function as we have added it to the  
prototype of the constructor function and all the employees objects can call it. */
e1.giveRaise(5000);
console.log(e1.salary);
console.log(e2.salary);
//****************************************************************************************