circle.java

Java与面向对象程序设计实验教学讲义.复数类的实现,复数类的复杂运算,身份证号码的分析,图形界面设计

public class Circle
{
   static double PI = 3.14159265;
   int radius;
   public double circumference()
   {
        return 2 * PI * radius;
   }
   public double area()
   {
       return PI * radius * radius;
   }
   public void enlarge(int factor) {
        radius = radius * factor;
   }
   public boolean fitsInside (Rectangle r) {
      return (2 * radius < r.width) && (2 * radius < r.height);
   }
}