說明：

• demo.cpp：main.cpp所在之處
• Line.h：線段類的.h檔案
• Line.cpp：線段類的.cpp檔案
• Coordinate.h：座標類的.h檔案
• Coordinate.cpp：座標類的.cpp檔案

之後的筆記都是這個模式，就不再贅述。在demo.cpp中有程式碼說明的註釋。

1. demo.cpp：
-----------------------------------
#include <iostream>
#include <stdlib.h>
#include "Line.h"
using namespace std;

/******************************/
 

/*
    建構函式和解構函式
    熟悉class類建立和銷燬的過程，明白其原理
*/
/******************************/

int main(void)
{
    Line *p = new Line(1,2,3,4);
    p->info();

    delete p;
    p = NULL;

    system("pause");
    return 0;
}

2. Coordinate.h:
-----------------------------------
class Coordinate{
public:
    Coordinate
 
(int x, int y);
    ~Coordinate();
    void setX(int x);
    int getX() const;  //在Line中定義的const Coordinate m_coorA;
    void setY(int y);
    int getY() const;
private:
    int m_iX;
    int m_iY;
};

3. Coordinate.cpp:
-----------------------------------
#include <iostream>
#include "Coordinate.h"
 

using namespace std;

Coordinate::Coordinate(int x, int y)
{
    m_iX = x;
    m_iY = y;
    cout<<"Coordinate() "<<m_iX<<","<<m_iY<<endl;
}
Coordinate::~Coordinate()
{
    cout<<"~Coordinate() "<<m_iX<<","<<m_iY<<endl;
}
void Coordinate::setX(int x)
{
    m_iX = x;
}
int Coordinate::getX() const
{
    return m_iX;
}
void Coordinate::setY(int y)
{
    m_iY = y;
}
int Coordinate::getY() const
{
    return m_iY;
}

4. Line.h:
-----------------------------------
#include "Coordinate.h"
class Line{
public:
    Line(int x1, int y1, int x2, int y2);
    ~Line();
    void setA(int x, int y);
    void setB(int x, int y);
    void info();
public:
    const Coordinate m_coorA; //常物件 資料成員
    Coordinate m_coorB; // 普通物件 資料成員
};

5. Line.cpp:
-----------------------------------
#include "Line.h"
#include <iostream>


using namespace std;

Line::Line(int x1, int y1, int x2, int y2):m_coorA(x1,y1),m_coorB(x2,y2)
{
    cout<<"Line()"<<endl;
}
Line::~Line()
{
    cout<<"~Line()"<<endl;
}
void Line::setA(int x, int y)
{
    //m_coorA.setX(x);
    //m_coorA.setY(y);
}
void Line::setB(int x, int y)
{
    //m_coorB.setX(x);
    //m_coorB.setY(y);
}
void Line::info()
{
    cout<<"("<<m_coorA.getX() <<","<<m_coorA.getY()<<")"<<endl;
    cout<<"("<<m_coorB.getX() <<","<<m_coorB.getY()<<")"<<endl;
}

F5後：