圆柱面积和体积建立一个无参构造方法

package Homework;
public class Yuan {
 private    double s;
 private    double v;
 private    double r;
 private    double h;
 private    double p=314;
//设置类的属性 面积 高 半径 等;
//建立一个无参构造方法;
//建立一个有参构造方法初始化半径和高;
   Yuan(){

   }
   Yuan(double r,double h){
    thisr = r;
    thish = h;
   }
//计算圆柱的面积和体积;
   public double mianji(double r){
       s = p * r *r;
       return  s;
   }
   public double  tiji(double r){
       v = mianji(r)*h;
       return  v;
   }
   void show(){
       Systemoutprintln("面积"+s+"体积"+v);
   }
}
//创建三个圆柱对象计算面积和体积;
package Homework;
import HomeworkYuan;
public class Test {
    public static void main(String[] args) {
       Yuan y1 = new Yuan(3,9);
       y1mianji(3);
       y1tiji(3);
       y1show();
       Yuan y2 = new Yuan(5,4) ;
       y2mianji(5);
       y2tiji(5);
       y2show();
       Yuan y3 = new Yuan(9,6);
       y3mianji(9);
       y3tiji(9);
       y3show();
    }
}