关于房贷计算的小程序，根据实际的还款计算公式编写，可根据贷款数额、利率、还款时间，计算出月供和还款总额，及还款一段时间后剩余的本金-Calculated on a small mortgage process, according to the actual formula for calculating the preparation of repayment under the loan amount, interest rates, the time for payment, calcul