#include <iostream>
using namespace std;
class point 
{
private:
    double fx,fy;
public:
    point();//不带参
    point(double fx,double fy);//带参
    void showpoint();
};
point::point()
{
    fx=0.0;
    fy=0.0;
}
point::point(double x,double y=5.0)
{
    fx=x;
    fy=y;
}
void point::showpoint()
{
    cout<<fx<<" "<<fy<<endl;
}
void main()
{
    point f1;
    cout<<"the fx and fy of f1: ";
    f1.showpoint();
    point f2(10);
    cout<<"the fx and fy of f2: ";
    f2.showpoint();
    point f3(1.1,2.0);
    cout<<"the fx and fy of f3: ";
    f3.showpoint();
}