JavaScript Object/ Class/ Getter methods

class Person{ 
  constructor(firstName, lastName) { 
  this.firstname = firstName; 
  this.lastname = lastName; 
  this._name = name; // create a private name property for the Person class 
 
 
// create a getter method for the name for the Person class 
  this.getName = function () { 
return this._name; 
}; 
 
  this.getFullName = function() { 
return this.firstname+ " " + this.lastname; 
  }; 
} 
} 
 
// extend Person class for the Employee and Customer classes. 
class Employee extends Person { 
  constructor(hireDate, salary){ 
 
  super(hireDate, salary); 
  this._hiredate = hireDate; // create a private property hire date for  Employee class 
  this._salary = salary; // create a private property salary for  Employee class 
 
  // create a getter method for the hire date s 
  this.getHireDate = function(){ 
  return this._hiredate; 
}; 
  // create a getter method for the salary 
  this.getSalary = function(){  //varianta alternativa:  Employee.prototype.getSalary = function(){ 
  return this._salary; 
}; 
} 
} 
 
 
class Customer extends Person { 
constructor(contractNumber){ 
 
super(contractNumber); 
this._contractNumber = contractNumber; // create a private contract number for Customer class 
 
 
//create a  getter for the contract number. 
this.getcontractNumber = function(){ 
return this._contractNumber; 
}; 
}; 
}