public PrincipalInterestBalance Add(PrincipalInterestBalance other)
{
return(new PrincipalInterestBalance
{
Interest = this.Interest + other.Interest,
Principal = this.Principal + other.Principal
});
}
public CreditCard(string name, double startingBalance, double ratePerPeriod, IDiscreteInterestCalculator interestCalculator)
{
Name = name;
_principalInterestBalance = new PrincipalInterestBalance {
Principal = startingBalance, Interest = 0
};
_rate = ratePerPeriod;
_interestCalculator = interestCalculator;
}
public void PassTime(int periods)
{
_principalInterestBalance += _interestCalculator.CalculateInterest(Principal, _rate, periods);
}