Favoring factory pattern over constructor pattern in JavaScript

favor-factory.js

//////////// constructor pattern

function Employee() {
  this.name = '';
  this.salary = 0; // no real encapsulation of private property
}

// too much code noises and bugs-prone from `prototype` and `this`

Employee.prototype.getSalary = function () {
  return this.salary;
};

Employee.prototype.setSalary = function (salary) {

  if (salary > 0) {
    this.salary = salary;
  }
};

Employee.prototype.print = function () {
  console.log('name: %s, salary: %d', this.name, this.salary);
};

//////////// factory pattern

function EmployeeFactory() {
  var salary = 0; // private

  var employee = {
    name: '', // public
    getSalary: getSalary,
    setSalary: setSalary,
    print: print
  };

  return employee;

  //////////// implementation details

  // free yourself from `prototype` and `this` mess which usually becomes the source of bugs ;)

  function getSalary() {
    return salary;
  }

  function setSalary(n) {

    if (n > 0) {
      salary = n;
    }
  }

  function print() {
    console.log('name: %s, salary: %d', employee.name, salary);
  }
}

//////////// test

var employee = new Employee();
employee.name = 'jaroslaw';
employee.setSalary(5000);
employee.salary = -5000; // oops.. leaking private property :(
employee.print(); // name: jaroslaw, salary: -5000

var employee1 = EmployeeFactory(); // no need to worry about forgetting calling `new`
employee1.name = 'glenn';
employee1.setSalary(1000);
employee1.salary = -1000; // private is safe by closure
employee1.print(); // name: glenn, salary: 1000