第九周上机实践项目2-Time类中的运算符重载（续）

分手后的思念是犯贱 2022-08-08 05:24 140阅读 0赞

在[Time类中的运算符重载][Time]基础上  
（1）定义对时间对象的自增和自减一目运算符

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1.  //一目运算符的重载  
2.  CTime operator++(**int**);//后置++，下一秒  
3.  CTime operator++();//前置++，下一秒，前置与后置返回值不一样  
4.  CTime operator--( **int**);//后置--，前一秒  
5.  CTime operator--();//前置--，前一秒

（2）定义Time类中的<<和>>运算符重载，实现时间的输入输出，改造原程序中对运算结果显示方式，使程序读起来更自然。

#include <iostream>
    #include <iomanip>
    using namespace std;
    class CTime
    {
    private:
        unsigned short int hour;    // 时
        unsigned short int minute;  // 分
        unsigned short int second;  // 秒
    public:
        CTime(int h=0,int m=0,int s=0):hour(h),minute(m),second(s) {};
        void setTime(int h,int m,int s);
        friend ostream& operator << (ostream&output,const CTime &c);
        //二目的比较运算符重载
        bool operator > (CTime &t);
        bool operator < (CTime &t);
        bool operator >= (CTime &t);
        bool operator <= (CTime &t);
        bool operator == (CTime &t);
        bool operator != (CTime &t);
        //二目的加减运算符的重载
        //返回t规定的时、分、秒后的时间
        //例t1(8,20,25),t2(11,20,50)，t1+t2为19:41:15
        CTime operator+(CTime &t);
        CTime operator-(CTime &t);//对照+理解
        CTime operator+(int s);//返回s秒后的时间
        CTime operator-(int s);//返回s秒前的时间
        //二目赋值运算符的重载
        CTime operator+=(CTime &c);
        CTime operator-=(CTime &c);
        CTime operator+=(int s);//返回s秒后的时间
        CTime operator-=(int s);//返回s秒前的时间
        //一目运算符的重载
        CTime operator++(int);//后置++，下一秒
        CTime operator++();//前置++，下一秒，前置与后置返回值不一样
        CTime operator--( int);//后置--，前一秒
        CTime operator--();//前置--，前一秒
    };
    void CTime::setTime(int h,int m,int s)
    {
        hour=h;
        minute=m;
        second=s;
    }
    ostream& operator << (ostream&output,const CTime &c)
    {
        output<<setw(2)<<setfill('0')<<c.hour<<":";
        output<<setw(2)<<setfill('0')<<c.minute<<":";
        output<<setw(2)<<setfill('0')<<c.second;
        return output;
    }
    bool CTime::operator > (CTime &t)
    {
        int t1,t2;
        t1=hour*3600+minute*60+second;
        t2=t.hour*3600+t.minute*60+t.second;
        if(t1>t2)
            return true;
        else
            return false;
    }
    bool CTime::operator < (CTime &t)
    {
        int t1,t2;
        t1=hour*3600+minute*60+second;
        t2=t.hour*3600+t.minute*60+t.second;
        if(t1<t2)
            return true;
        else
            return false;
    }
    bool CTime::operator <=     *this=*this-t0;
        return *this;(CTime &t)
    {
        return !(*this>t);
    }
    bool CTime::operator >= (CTime &t)
    {
        return !(*this<t);
    }
    bool CTime::operator == (CTime &t)
    {
        if(hour==t.hour&&minute==t.minute&&second==t.second)
            return true;
        else
            return false;
    }
    bool CTime::operator != (CTime &t)
    {
        return !(*this==t);
    }
    CTime CTime::operator + (CTime &t)
    {
        CTime t1;
        t1.second=second+t.second;
        t1.minute=minute+t.minute;
        t1.hour=hour+t.hour;
        if(t1.second>59)
        {
            t1.second%=60;
            t1.minute++;
        }
        if(t1.minute>59)
        {
            t1.minute%=60;
            t1.hour++;
        }
        if(t1.hour>23)
        {
            hour%=24;
        }
        return t1;
    }
    CTime CTime::operator - (CTime &t)
    {
        int h,m,s;
        s=second-t.second;
        m=minute-t.minute;
        h=hour-t.hour;
        if (s<0)
        {
            s+=60;
            m--;
        }
        if (m<0)
        {
            m+=60;
            h--;
        }
        while (h<0) h+=24;
        CTime t0(h,m,s);
        return t0;
    }
    CTime CTime::operator+(int s)
    {
        CTime t1(0,0,s);
        return *this+t1;
    }
    CTime CTime::operator-(int s)
    {
        CTime t1(0,0,s);
        return *this-t1;
    }
    //可以直接使用已经重载了的加减运算实现
    //这种赋值, 例如 t1+=20，直接改变当前对象的值，所以在运算完成后，将*this作为返回值
    CTime CTime::operator+=(CTime &c)
    {
        *this=*this+c;
        return *this;
    }
    CTime CTime::operator-=(CTime &c)
    {
        *this=*this-c;
        return *this;
    }
    CTime CTime::operator+=(int s)//返回s秒后的时间
    {
        int ss=s%60;
        int mm=(s/60)%60;
        int hh=s/3600;
        CTime t0(hh,mm,ss);
        *this=*this+t0;
        return *this;
    }
    CTime CTime::operator-=(int s)//返回s秒前的时间
    {
        int ss=s%60;
        int mm=(s/60)%60;
        int hh=s/3600;
        CTime t0(hh,mm,ss),t;
        *this=*this-t0;
        return *this;
    }
    //下面定义用于测试的main()函数
    //一目运算符的重载
    CTime CTime::operator++(int)//后置++，下一秒
    {
        CTime c=*this;
        *this+=1;
        return c;
    }
    CTime CTime::operator++()//前置++，下一秒，前置与后置返回值不一样
    {
        *this+=1;
        return *this;
    }
    CTime CTime::operator--( int)//后置--，前一秒
    {
        CTime c=*this;
        *this-=1;
        return c;
    }
    CTime CTime::operator--()//前置--，前一秒
    {
        *this-=1;
        return *this;
    }
    int main()
    {
        CTime t1,t2,t3;
        int s=20;
        t1.setTime(8,20,25);
        t2.setTime(11,20,50);
        cout<<"t1的时间为："<<t1<<endl;
        cout<<"t2的时间为："<<t2<<endl;
        cout<<"t1是否比t2大？"<<endl;
        cout<<((t1>t2)?"是":"否")<<endl;
        cout<<"t1是否比t2小？"<<endl;
        cout<<((t1<t2)?"是":"否")<<endl;
        cout<<"t1是否大于或等于t2？"<<endl;
        cout<<((t1>=t2)?"是":"否")<<endl;
        cout<<"t1是否小于或等于t2？"<<endl;
        cout<<((t1<=t2)?"是":"否")<<endl;
        cout<<"t1是否等于t2？"<<endl;
        cout<<((t1==t2)?"是":"否")<<endl;
        cout<<"t1是否不等于t2？"<<endl;
        cout<<((t1!=t2)?"是":"否")<<endl;
        cout<<t1<<"+"<<t2<<"="<<t1+t2<<endl;
        cout<<t1<<"-"<<t2<<"="<<t1-t2<<endl;
        cout<<t1<<"+"<<s<<"s"<<"=";
        t3=t1+s;
        cout<<t3<<endl;
        cout<<t1<<"-"<<s<<"s"<<"=";
        t3=t1-s;
        cout<<t3<<endl;
        cout<<t1<<"+="<<t2<<"=";
        t1+=t2;
        cout<<t1<<endl;
        cout<<t1<<"-="<<t2<<"=";
        t1-=t2;
        cout<<t1<<endl;
        cout<<t1<<"+="<<s<<"s"<<" = ";
        t1+=s;
        cout<<t1<<endl;
        cout<<t1<<"-="<<s<<"s"<<" = ";
        t1-=s;
        cout<<t1<<endl;
        cout<<t1<<"++ = ";
        cout<<(t1++)<<endl;
        cout<<"++"<<t1<<" = ";
        cout<<(++t1)<<endl;
        cout<<t2<<"-- = ";
        cout<<(t2--)<<endl;
        cout<<"--"<<t2<<" = ";
        cout<<(--t2)<<endl;
    }

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心得：

要吐血了，老是错

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