练习2

package com.atguigu.exercise;
public class PassObject {
    public static void main(String[] args) {
  Object t = new Object();
  Circle c = new Circle();
  t.printAreas(c, 5);
  System.out.println("now radius is " + c.radius);
    }
}
class Object{
    public void printAreas(Circle c, int time) {
  System.out.println("Radius \t \t Area");
  // 设置圆的半径
  for (int i = 1; i <= time; i++) {
      c.radius = i;
      System.out.println(c.radius + "\t\t" + c.findArea());
  }
  c.radius = time + 1;
    }
}
class Circle {
    double radius;// 半径
    // 求圆的面积
    public double findArea() {
  return Math.PI * radius * radius;
    }
}