类与对象（一）

实验步骤：
第一步：声明一个时间类

#include<iostream>
using namespace std;
class Time
{
private:
    int Hour,Minute,Second;
public:
    void SetTime(int h,int m,int s);
    void Print_Time();
};
void Time::SetTime(int h,int m,int s)
{
    Hour=h;
    Minute=m;
    Second=s;
}
void Time::Print_Time()
{
    cout<<Hour<<":";
    cout<<Minute<<":";
    cout<<Second<<endl;
}

第二步：编写主函数调试时间类。

int main()
{
    Time mytime;
    mytime.SetTime(9,20,30);
    mytime.Print_Time();
    return 0;
}

第三步：用构造函数代替上面的SetTime成员函数。

#include<iostream>
using namespace std;
class Time
{
private:
    int Hour,Minute,Second;
public:
    Time(int h,int m,int s);
    void Print_Time();
};
Time::Time(int h,int m,int s)
{
    Hour=h;
    Minute=m;
    Second=s;
}
void Time::Print_Time()
{
    cout<<Hour<<":";
    cout<<Minute<<":";
    cout<<Second<<endl;
}
int main()
{
    Time mytime(10,40,50);
    mytime.Print_Time();
    return 0;
}

第四步：重载构造函数。

Time::Time()
{
    Hour=0;
    Minute=0;
    Second=0;
}

第五步：将上面的类声明改为

class Time
{
private:
    int Hour,Minute,Second;
public:
    Time(int h,int m,int s);
    Time();
    ~Time();
    void Print_Time();
};

并增加析构函数

Time::~Time()
{
    cout<<"God bye"<<endl;
}

第六步：

#include<iostream>
using namespace std;
class Time
{
private:
    int Hour,Minute,Second;
public:
    Time(int h,int m,int s);
    Time();
    Time(Time &t);
    ~Time();
    void Print_Time();
};
Time::Time(int h,int m,int s)
{
    Hour=h;
    Minute=m;
    Second=s;
}
void Time::Print_Time()
{
    cout<<Hour<<":";
    cout<<Minute<<":";
    cout<<Second<<endl;
}
Time::Time(Time &t)
{
    Hour=0;
    Minute=0;
    Second=0;
}
Time::~Time()
{
    cout<<"God bye"<<endl;
}
int main()
{
    Time mytime(10,40,50);
    Time yourtime(mytime);
    mytime.Print_Time();
    yourtime.Print_Time();
    return 0;
}

第七步：根据题目要求定义Stock类如下

#include <iostream>
using namespace std;
class Stock
{
private:
    int Number;
    float Max,Min,Begin,End;
public:
    Stock(int n,float ma,float mi,float b,float e);
    void Set_Stock(int n,float ma,float mi,float b,float e);
    float Get_End();
    void Show_Stock();
};
Stock::Stock(int n,float ma,float mi,float b,float e)
{
    Number=n;
    Max=ma;
    Min=mi;
    Begin=b;
    End=e;
}
void Stock::Set_Stock(int n,float ma,float mi,float b,float e)
{
    Number=n;
    Max=ma;
    Min=mi;
    Begin=b;
    End=e;
}
float Stock::Get_End()
{
    return End;
}
void Stock::Show_Stock()
{
    cout<<Number<<"\t";
    cout<<Max<<"\t";
    cout<<Min<<"\t";
    cout<<Begin<<"\t";
    cout<<End<<endl;
}

第八步：编写主函数调试Stock类

int main()
{
    Stock s1(1,4.18,4.00,4.05,4.09);
    Stock s2(2,4.41,4.03,4.04,4.40);
    cout<<"\n"<<(s2.Get_End()-s1.Get_End())/s1.Get_End()*100<<"%";
    return 0;
}

日期：2020年3月2日