areatester.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 AreaTester {
    public static void main(String args[])
    {
        Circle c = new Circle();
        c.radius = 50;
        Rectangle r = new Rectangle();
        r.width = 20;
        r.height = 30;
        System.out.println("Circle has area " + c.area());
        System.out.println("Rectangle has area " + r.area());
      }
}