继承中怎么把父类的对象带给子类

Question

import java.util.*;
 class Yuan{
    private double radius;
    double  pai=3.14;
   Yuan(double radius){
        this.radius=radius;
       }
    public void setradius(double radius){
     this.radius=radius;
    }
    public double getCircumference(){
       return 2*pai*radius;
    }
    public double getCirclearea(){
       return pai*radius*radius;
    }
}
class Cylinder extends Yuan{
    double cylinderhigh;
    Cylinder
    Cylinder(double radius,double cylinderhigh ){
        this.cylinderhigh=cylinderhigh;
       0setradius(radius);
    
    }
   
    public double getCylindervolume()
     {
        return getCirclearea()*cylinderhigh;
      }
     public double getCylinderarea()
     {
       return 2*getCirclearea()+getCircumference()*cylinderhigh;
      }
 }
class Tex{
     public static void main(String args [] ){
           Scanner sc=new Scanner(System.in);
           System.out.println("请输入圆柱体");
            float radius1=sc.nextInt();
           System.out.println("请输入圆柱体的高");
            float cylinderhigh=sc.nextInt();
           Cylinder cy=new Cylinder(cylinderhigh);
           TheBall ball1=new TheBall(radius1);
           System.out.println(cy.getCylindervolume()+"圆柱体体积");
          System.out.println(cy.getCylinderarea()+"圆柱体表面积");
         
    }   

Answer 1

public class Cylinder extends Yuan {
    double cylinderhigh;

    Cylinder(double radius) {
        super(radius);
    }
    Cylinder(double radius,double cylinderhigh ){
        super(radius);//这个相当于给radius赋值
        this.cylinderhigh=cylinderhigh;
//        setradius(radius);
    }

    public double getCylindervolume()
    {
        return getCirclearea()*cylinderhigh;
    }
    public double getCylinderarea()
    {
        return 2*getCirclearea()+getCircumference()*cylinderhigh;
    }
}