Hi, I've written this simple program but it doesn't run. it doesn't show error but after build and run only shows "exited with code 0" instead of some strings whixh i've written in main body.

PHP Code:
#ifndef mainwindow_H
#define mainwindow_H

class mainwindow
{
private:
        
double a;
        
double b;

public:
        
mainwindow()
        {
            
0.0;
            
0.0;
        }

        
mainwindow(double xdouble y)
        {
            
x;
            
y;
        }

        
void setA(double x)
        {
            
x;
        }

        
void setB(double y)
        {
            
y;
        }

        
double getA()
        {
            return 
a;
        }

        
double getB()
        {
            return 
b;
        }

        
void add(double xdouble y)
        {
            
y;
        }

        
void sub(double xdouble y)
        {
            
y;
        }

        
void mul(double xdouble y)
        {
            
y;
        }

        
void div(double xdouble y)
        {
            
y;
        }
};

#endif 
PHP Code:
#include <iostream>
#include "mainwindow.h"

int main()
{
    
std::cout << "Program starts. . ." << std::endl;

    
mainwindow test1;
    
mainwindow test2(0.6660.875);

    
std::cout << "A = " << test1.getA() << std::endl;
    
std::cout << "B = " << test2.getB() << std::endl;

    
test1.setB(test2.getB());
    
test2.setA(test1.getA());

    
std::cout << "A = " << test1.getA() << std::endl;
    
std::cout << "B = " << test2.getB() << std::endl;

    return 
0;