[Java]_ch11.2_不同類別庫間存取

[Java]_ch11.2_不同類別庫間存取

package Taipei;

public class CCircle{

protected double pi=3.14;

protected double radius;

public CCircle(){

radius=1.0;

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

}

public CCircle(double r){

radius=r;

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

}

public final void show() {

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

}

}





package Hsinchu;

public class CCoin extends Taipei.CCircle{

int value;

public CCoin(){

// super(1);

value=5;

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

}

public CCoin(double v){

super(v);

value=(int)v;

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

}

public void setValue(int v) {

value=v;

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

}

// void show() {

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

// }

public String toString() {

String data="物件內容: radius="+radius+" pi="+pi+" value="+value;

return data;

}

}

package Gjun;

public class A9 {

public static void main(String[] args) {

Taipei.CCircle c1=new Taipei.CCircle();

c1.show();

// c1.setValue(999);

Hsinchu.CCoin c2=new Hsinchu.CCoin();

c2.show();

c2.setValue(100);

Taipei.CCircle c3=new Hsinchu.CCoin(4.0);

c3.show();

// c3.setValue(50);

Hsinchu.CCoin c4=(Hsinchu.CCoin) c3;

System.out.println("c1.getClass()="+c1.getClass());

System.out.println("c2.getClass()="+c2.getClass());

System.out.println("c3.getClass()="+c3.getClass());

System.out.println(c3.equals(c4)?"同一物件":"不同物件");

System.out.println(c3.equals(c1)?"同一物件":"不同物件");

System.out.println("c3.toString()="+c3.toString());

System.out.println("c1.toString()="+c1.toString());

System.out.println("c2.toString()="+c2.toString());

}

}