我的温度转换有什么问题？

Question

在这个程序中,我试图取78华氏度并将其返回到Celsius版本和开尔文的类中.但由于一些奇怪的原因,我只是把它作为输出.我究竟做错了什么？

这是我的输出.

78
0
273.15

#include <iostream>
using namespace std;


class Temperature
{
public:

    double getTempKelvin();
    double getTempFahrenheit();
    double getTempCelcius();

    void setTempKelvin(double k);
    void setTempFahrenheit(double f);
    void setTempCelcius(double c);

private:
    double kelvin, fahrenheit, celcius;
    double c, f, k;
};

int main ()
{
    double c, f, k;
    Temperature Conv;

    Conv.setTempFahrenheit(f);
    Conv.setTempCelcius(c);
    Conv.setTempKelvin(k);
    cout << Conv.getTempFahrenheit() << endl;
    cout << Conv.getTempCelcius() << endl;
    cout << Conv.getTempKelvin() << endl;



    return 0;
}

void Temperature::setTempFahrenheit(double f)
{
    f = 78;
    fahrenheit = f;
}

void Temperature::setTempCelcius(double c)
{
    c = (5/9) * ( f - 32);
    celcius = c;
}

void Temperature::setTempKelvin(double k)
{
    k = c + 273.15;
    kelvin = k;
}




double Temperature::getTempFahrenheit()
{
    return fahrenheit;
}

double Temperature::getTempCelcius()
{
    return celcius;
}


double Temperature::getTempKelvin()
{
    return kelvin;
}

Answer 1

5/9是整数除法,将导致0.你需要使用双打,试试:

void Temperature::setTempCelcius(double c)
{
    c = (5.0/9.0) * ( f - 32);
    celcius = c;
}