[Java]_ch11.3_建構Package的階層關係

[Java]_ch11.3_建構Package的階層關係



package YPU.Taipei;



public class CCircle{

protected double pi=3.14;

protected double radius;

protected CCircle(){

radius=1.0;

System.out.println("0.父類別建構元(), pi="+pi+" radius="+radius);

}

public CCircle(double r){

radius=r;

System.out.println("1.父類別建構元(double r), pi="+pi+" radius="+radius);

}

public final void show(){

System.out.println("父類別show(), pi="+pi+" radius="+radius+" area="+pi*radius*radius);

}

public void setValue(int v){}

}

package YPU.Hsinchu;

import YPU.Taipei.CCircle;

public class CCoin extends CCircle{

int value;

public CCoin(){

      super(4.0);

value=5;

System.out.println("0.子類別建構元(), pi="+pi+" radius="+radius+" value="+value);

}

public CCoin(double v){

value=(int)v;

System.out.println("1.子類別建構元(double v), pi="+pi+" radius="+radius+" value="+value);

}

public void setValue(int v){

value=v;

System.out.println("子類別setValue(), value="+value+" pi="+pi+" radius="+radius);

}

// public void show(){

// System.out.println("子類別show(), pi="+pi+" radius="+radius+" area="+pi*radius*radius+" value="+value);

// }

}

package YPU;

import YPU.Hsinchu.CCoin;

import YPU.Taipei.CCircle;

public class A9 {

public static void main(String[] args) {

CCircle c1=new CCircle(2.0);

c1.show();

// c1.setValue(50);

CCoin c2=new CCoin();

c2.setValue(100);

c2.show();

CCircle c3=new CCoin(99);

c3.show();

c3.setValue(88);

}

}