final class Circle{
double r;
public static final double PI=3.14;//常量
public Circle(double r) {
this.r=r;
}
/*public Circle() { }
*/
public final void getArea() {
System.out.println("面积是："+PI*r*r);
}
}
class Demo57 {
public static void main(String[]args) {
final Circle c=new Circle(3.0);
print(c);
print1(c);
}
public static void print(final Circle c) {
//c = new Circle(4.0); // c指向了新的对象。
c.getArea();
}
public static void print1(Circle c) {
c=new Circle(4.0);
c.getArea();
}
