C++(三)一個有理數類

class rational
{
public:
 rational(int numerator=1,int demominator=1);
 rational(const rational&);
 int GetNumerator() const;
 int GetDemominator() const;
 void PrintRational() const;
 void SetNumerator(int numberator);
 void SetDemominator(int demominator);
 const rational operator=(const rational&);
private:
 int numerator;
 int demominator;
};

rational::rational(int numerator,int demominator):numerator(numerator),
demominator(demominator)
{

}

rational::rational(const rational& rhs):numerator(rhs.GetNumerator()),
demominator(rhs.GetDemominator())
{
 
}

const rational rational::operator=(const rational& rhs)
{
 return rational(rhs.GetNumerator(),rhs.GetDemominator());
}

int rational::GetDemominator() const
{
 return demominator;
}

int rational::GetNumerator() const
{
 return numerator;
}

void rational::SetDemominator(int demominator)
{
 demominator=demominator;
}

void rational::SetNumerator(int numberator)
{
 numberator=numberator;
}

void rational::PrintRational() const
{
 cout<<"rational("<<GetNumerator()<<","<<GetDemominator()<<")"<<endl;
}

const rational operator*(const rational& rhs1,const rational& rhs2)
{
 return rational(rhs1.GetNumerator()*rhs2.GetNumerator(),
  rhs1.GetDemominator()*rhs2.GetDemominator());
}