类的封装和抽象

ackage 类的抽象与封装;

public class yuan {   
 
   private double Radius;   
   public double circle() {
    return Radius;
   }
   public void circle(double r) {             
    Radius = r;
   }
   public yuan( ){
    System.out.println("圆！");
   }
   public yuan(double  r){
    this.Radius = r;
   }
   public double getArea(double r){
    return Math.PI * r * r;
   }
   public double getPerimeter(double r){
    return 2 * Math.PI * r;
   }
   public void  show( ){
    System.out.println("圆的面积： " + this.getArea(Radius));
    System.out.println("圆的周长： " + this.getPerimeter(Radius));
   }
 }

  

package 类的抽象与封装;
public class yuanzhu extends yuan {
 
   
 private double hight;
     
      public yuanzhu (double r, double  h )
      {
   
       super(r);
       this.hight = h;
      }
      public double getVolume()

{
       return Math.PI * this.circle() * this.circle() * hight;
       
      }  
      public void showVolume( ){
       System.out.println("圆柱体的体积：" + this.getVolume());
      }
    }

package 类的抽象与封装;
import java.util.Scanner;
public class 主函数 {
 
 public static void main(String[] args)

{
   double r,h;
   Scanner in=new Scanner(System.in);
  System.out.print("输入圆的半径");
  r=in.nextInt();
  yuan c1=new yuan(r);
  c1.show( );
  Scanner i=new Scanner(System.in);
  System.out.print("输入圆柱的高");
  h=i.nextInt();
  yuanzhu c2=new yuanzhu(r,h);
  c2.showVolume( );
 }

}