找回感觉的练习

一：注释

参数price代表房屋每平方米的价格，area代表房屋的总平方数

double downPay(double price,double area)：一个计算房屋首付款的方法，重写计算房屋首付款的方法

三 代码部分

1.Payment类

package com;

public interface Payment {
    
    double downPay(double price,double area);
}

 

2.test类

package com;

public class Test {

    /**
     * @param args
     */
    public static void main(String[] args) {
        Residence  re=new Residence();
        
        Payment pay=new Commercial();//接口回调
        System.out.println("住宅产权房屋的首付总房款"+re.downPay(5, 100));
        System.out.println("商业产权房屋的首付总房款"+pay.downPay(5, 100));
        
        
        
    }

}

3.Residence类

package com;

public class Residence implements Payment  {//（住宅产权房屋类）
    
    public double downPay(double price,double area){

        return(0.2*price*area);
    }

}

4.Commercial类

package com;

public class Commercial implements Payment { //（商业产权房屋类）
    

    public double downPay(double price,double area){
    
        return(0.45*price*area);
    }
}

5.测试部分