來來來交作業
package?homework;
public?abstract?class?shape?{
????public?abstract?void?perimeter();
????public?abstract?void?area();
????}public class Rectangle extends shape {
int h = 5;
int w = 3;
public void perimeter() {
System.out.println("矩形周長為:"+2*(h+w));
}
@Override
public void area() {
System.out.println("矩形面積為:"+(h*w));
}
}
public class Circle extends shape {
float r = 3.2f;?
float π = 3.14f;
@Override
public void perimeter() {
System.out.println("圓周長為:"+2*π*r);
}
@Override
public void area() {
System.out.println("圓面積為:"+r*π*r);
}
}
public class test {
public static void main(String[] args) {
Rectangle re = new Rectangle();
re.perimeter();
re.area();
Circle ci = new Circle();
ci.area();
ci.perimeter();
}
}
2018-09-03
Shape re = new Rectangle();
re.peruneter();
re.area();
Shape ci = new Circle();
ci.area();
ci.peruneter();
這個就是使用多態。
2018-09-01
測試類要用多態吧!