Определите класс дробей. Определите класс дробей

#include <iostream>
#include <conio.h>
using namespace std;
class Drob
{
private:
    int ch1,ch2,zh1,zh2;
    double drob1,drob2;
public:
    Drob(int c1,int c2,int z1,int z2);
    void Add();
    void Div();
    void Mul();
    void Sub();
    void Sokrajenie();
};
Drob::Drob(int c1,int c2,int z1,int z2)
{
    ch1=c1;ch2=c2;zh1=z1;zh2=z2;
    double drob1=(double)ch1/zh1;
    double drob2=(double)ch2/zh2;
}
void Drob::Add()
{
    cout<<"Otvet: "<<(double)drob1+drob2<<endl;
}
void Drob::Sub()
{
    cout<<"Otvet: "<<(double)drob1-drob2<<endl;
}
void Drob::Mul()
{
    cout<<"Otvet: "<<(double)drob1*drob2<<endl;
}
void Drob::Div()
{
    cout<<"Otvet: "<<(double)drob1/drob2<<endl;
}
void Drob::Sokrajenie()
{
    bool off=true;
    while(off==true)
    {
        if(ch1%2==0 && zh1%2==0) { ch1=ch1/2;zh1=zh1/2; }
        else if(ch1%3==0 && zh1%3==0) { ch1=ch1/3;zh1=zh1/3; }
        else if(ch1%5==0 && zh1%5==0) { ch1=ch1/5;zh1=zh1/5; }
        else if(ch1%7==0 && zh1%7==0) { ch1=ch1/7;zh1=zh1/7; }
        else if(ch2%2==0 && zh2%2==0) { ch2=ch2/2;zh2=zh2/2; }
        else if(ch2%3==0 && zh2%3==0) { ch2=ch2/3;zh2=zh2/3; }
        else if(ch2%5==0 && zh2%5==0) { ch2=ch2/5;zh2=zh2/5; }
        else if(ch2%7==0 && zh2%7==0) { ch2=ch2/7;zh2=zh2/7; }
        else off=false;
    }
    drob1=(double)ch1/zh1;
    drob2=(double)ch2/zh2;
    cout<<"Drob 1: "<<drob1<<endl;
    cout<<"Drob 2: "<<drob2<<endl;
}
int main()
{
    Drob obj(3,4,2,3);
    cout<<"Slojenie: "<<endl;
    obj.Add();
    cout<<"Raznost': "<<endl;
    obj.Sub();
    cout<<"Umnojenie: "<<endl;
    obj.Mul();
    cout<<"Delenie: "<<endl;
    obj.Div();
    Drob obj1(4,10,2,5);
    obj1.Sokrajenie();
    getch();
    return 0;
}