找回感觉的练习

package a;


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

}

package a;

public class Residence implements Payment {
	public double downPay (double price , double area){
        return (price * area * 0.20);

}
}

　　

package a;

public class Commercial implements Payment {
	public double downPay (double price , double area){
        return (price * area * 0.45);
	

}
}

　　

package a;

import java.util.Scanner;

public class test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		
		double price;
		double area;
		Residence a=new Residence();
		 Commercial b= new Commercial();
		 Scanner re =new Scanner(System.in);
		 System.out.println("输入房屋每平米价格");
		 price = re.nextDouble();
		 System.out.println("输入房屋面积");
		 area = re.nextDouble();
		 System.out.println("住宅产权房屋的首付："+a.downPay(price, area));
		 System.out.println("商业产权房屋的首付："+b.downPay(price, area));
		 
		 
		
		

	}

}