Question

C++用操作符重载方法实现有理数的四则运算

Answer 1

class CRational
{
private:
    double ra;
public:
    CRational(double val)
    {
        ra=val;
    }
    CRational(CRational &val)
    {
        ra=val.ra;
    }
    CRational operator + (CRational &a)
    {
        return a.ra+ra;
    }
    CRational operator - (CRational &a)
    {
        return ra-a.ra;
    }
    CRational operator * (CRational &a)
    {
        return a.ra*ra;
    }
    CRational operator / (CRational &a)
    {
        return ra/a.ra;
    }
};

这个意义何在？

追问

操作符重载后，是括号里的参数变得具有+-*/的作用吗？
还有在main函数里面怎么调用啊？可以把main函数写出来吗
本人刚学C++，菜鸟一个

追答

int main()
{
CRational a(1),b(2),c;
c=a+b;
}

追问

谢谢回复
[Error] no matching function for call to 'CRational::CRational(CRational)'
编译器显示没有匹配的函数可调用？

追答

class CRational
{
private:
double ra;
public:
CRational(double val)
{
ra=val;
}
CRational()
{

}
CRational(CRational &val)
{
ra=val.ra;
}
CRational operator + (CRational &a)
{
return CRational(a.ra+ra);
}
CRational operator - (CRational &a)
{
return CRational(ra-a.ra);
}
CRational operator * (CRational &a)
{
return CRational(a.ra*ra);
}
CRational operator / (CRational &a)
{
return CRational(ra/a.ra);
}
};
int main()
{
CRational a(1),b(1),c;
c=a+b;
}

追问

谢谢你
不过还是报相同错误
[Error] no matching function for call to 'CRational::CRational(CRational)'
是要返回this指针吗

追答

Visual Studio 2012 编译通过

Answer 2

写一些运算符重载函数，如如何让一个整型数据和一个浮点型数据相加，c++头文件里可没有这个
float count(int a,float b)
{
return (a+b);注意这里返回值是float型的
}