---接口代码:
package com.yikuan.cn;
public interface Shape {
public abstract void area();
}
--两个子类代码:
public class Circle implements Shape {
private double r;
public Circle(double r) {
super();
this.r = r;
}
@Override
public void area() {
System.out.println(2*Math.PI*r);
}
}
public class Area implements Shape{
private double r;
public Area(double r) {
super();
this.r = r;
}
@Override
public void area() {
System.out.println(Math.PI*r*r);
}
}
---测试类代码:
package com.yikuan.cn;
public class Test1 {
public static void main(String[] args) {
Area a1 = new Area(5);
a1.area();
Circle c1 = new Circle(3);
c1.area();
}
}