private int r;
public Circle(int r){
this.r=r;
}
public int getr(){
return r;
}
public double getArea(){
return Math.PI*r*r;
}
public double getCircleLength(){
return Math.PI*2*r;
}
}
public class CircleComputer{
public static void main(String []args){
Circle a=new Circle(1);
System.out.println("圓半徑r= "+a.getr());
System.out.println("圓面積為："+a.getArea());
System.out.println("圓周長為："+a.getCircleLength());
}
}