Classe js

gistfile1.js

;(function(exports){
  function PaymentCalculator (value, fine, interest) {
    this._value = value;
    this._fine = fine;
    this._interest = interest;
  }

  PaymentCalculator.prototype.value = function () {
    return this._value;
  };

  PaymentCalculator.prototype.fine = function () {
    return this._fine;
  };

  PaymentCalculator.prototype.interest = function () {
    return this._interest;
  };

  PaymentCalculator.prototype.total = function () {
    return this.value() + this.fine() + this.interest();
  };

  exports.PaymentCalculator = PaymentCalculator;
})(window);