实验七 运算符重载

实验目的和要求

熟悉运算符重载的定义和使用方法 

实验内容

1.调试下列程序

//sy7_1.cpp  
#include<iostream>  
using namespace std;  
class complex  
{  
    public:  
        complex(){real=imag=0.0;}  
        complex(double r){real=r;imag=0.0;}  
        complex(double r,double i){real=r;imag=i;}  
        complex operator + (const complex &c);  
        complex operator - (const complex &c);  
        complex operator * (const complex &c);  
        complex operator / (const complex &c);  
        friend void print(const complex &c);  
    private:  
        double real,imag;  
};  
inline complex complex::operator + (const complex &c)  
{  
    return complex(real+c.real,imag+c.imag);  
}  
inline complex complex::operator - (const complex &c)  
{  
    return complex(real-c.real,imag-c.imag);  
}  
inline complex complex::operator * (const complex &c)  
{  
    return complex(real*c.real-imag*c.imag,real*c.imag+imag*c.real);  
}  
inline complex complex::operator / (const complex &c)  
{  
    return complex((real*c.real+imag*c.imag)/(c.real*c.real+c.imag*c.imag),(imag*c.real-real*c.imag)/(c.real*c.real+c.imag*c.imag));  
}  
void print(const complex &c)  
{  
    if(c.imag<0)  
        cout<<c.real<<c.imag<<"i";  
    else  
        cout<<c.real<<"+"<<c.imag<<"i";  
}  
int main()  
{  
    complex c1(2.0),c2(3.0,-1.0),c3;  
    c3=c1+c2;  
    cout<<"\nc1+c2= ";  
    print(c3);  
    c3=c1-c2;  
    cout<<"\nc1-c2= ";  
    print(c3);  
    c3=c1*c2;  
    cout<<"\nc1*c2= ";  
    print(c3);  
    c3=c1/c2;  
    cout<<"\nc1/c2= ";  
    print(c3);  
    c3=(c1+c2)*(c1-c2)*c2/c1;  
    cout<<"\n(c1+c2)*(c1-c2)*c2/c1= ";  
    print(c3);  
    cout<<endl;  
    return 0;  
}

写出程序的输出结果，并解释

实验结果如下：

2.调试下列程序

//sy7_2.cpp
#include<iostream>
using namespace std;
class complex
{
    public:
        complex(){real=imag=0.0;}
        complex(double r){real=r;imag=0.0;}
        complex(double r,double i){real=r;imag=i;}
        friend complex operator + (const complex &c1,const complex &c2);
        friend complex operator - (const complex &c1,const complex &c2);
        friend complex operator * (const complex &c1,const complex &c2);
        friend complex operator / (const complex &c1,const complex &c2);
        friend void print(const complex &c);
    private:
        double real,imag;
};
complex operator + (const complex &c1,const complex &c2)
{
    return complex(c1.real+c2.real,c1.imag+c2.imag);
}
complex operator - (const complex &c1,const complex &c2)
{
    return complex(c1.real-c2.real,c1.imag-c2.imag);
}
complex operator * (const complex &c1,const complex &c2)
{
    return complex(c1.real*c2.real-c1.imag*c2.imag,c1.real*c2.imag+c1.imag*c2.real);
}
complex operator / (const complex &c1,const complex &c2)
{
    return complex((c1.real*c2.real+c1.imag*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag),(c1.imag*c2.real-c1.real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag));
}
void print(const complex &c)
{
    if(c.imag<0)
        cout<<c.real<<c.imag<<"i";
    else
        cout<<c.real<<"+"<<c.imag<<"i";
}
int main()
{
    complex c1(2.0),c2(3.0,-1.0),c3;
    c3=c1+c2;
    cout<<"\nc1+c2= ";
    print(c3);
    c3=c1-c2;
    cout<<"\nc1-c2= ";
    print(c3);
    c3=c1*c2;
    cout<<"\nc1*c2= ";
    print(c3);
    c3=c1/c2;
    cout<<"\nc1/c2= ";
    print(c3);
    c3=(c1+c2)*(c1-c2)*c2/c1;
    cout<<"\n(c1+c2)*(c1-c2)*c2/c1= ";
    print(c3);
    cout<<endl;
    return 0;
}

写出程序的输出的结果，并解释。

程序结果如下;

3.定义一个Time类用来保存时间（时、分、秒），通过重载操作符“+”实现两个时间的相加（sy7-3.cpp）

分析与讨论

结合上题中的程序总结运算符重载的形式。

实验总结

首先，本次实验的基础是必须了解并掌握模板的概念，而模板的类属参数由调用实际参数的具体数据类型替换，并由编译器生成一段真正可以运行的代码，而这个过程叫做实例化。其次，函数模板的重载也使我们必须掌握的知识点，函数模板有很多的重载方式，可以定义同名的函数模板，提供不同的参数和实现，也可以用其他非模板函数重载。综合书上的理论知识，运用在实验中分析程序，利用实践加深我们对课本知识的学习，所以实验对我们的帮助还是很大的。