简单的继承问题

class Bank{
    int saveMoney;
    int year;
    double interest;
    public double computerInterest(){
        interest = year * 0.035 * saveMoney;
        return interest;
    }
}
 class ConstructionBank extends Bank{
    double year;
    public double computerInterest(){
        super.year = (int)year;
        double remainNumber = year - (int)year;
        int day = (int)(remainNumber * 1000);
        interest = super.computerInterest() + day * 0.0001 * saveMoney;
        System.out.printf("%d 元存%d 年零%d 天\n",saveMoney,super.year,day);
        return interest;
    }
}
public class Main{
    public static void main(String args[]){
        int amount = 8000;
        ConstructionBank bank=new ConstructionBank();
        bank.year = 5.216;
        bank.saveMoney=amount;
        bank.computerInterest();
        System.out.printf("%.3f",bank.interest);//printf的%f就可以表示double
    }
}




结果：

8000 元存 5 年零 216 天
利息是 1572.800 元