Why is the error in c++ code?

Question

C++ / C#

I run the program

#include <iostream>
using namespace std;

int main()
{
    
    for (double i = 0; i < 100; i++) {
        cout << i << "земной фут равен" << i * 0, 19 << "футов \n" ;
                                                                                   
    };

}

marks an error in "feet \n" , why?

Answer 1

#include <iostream>
using namespace std;

int main()
{

for (double i = 0; i < 100; i++)
{
   cout << i << "земной фут равен" << i * 0,19;
   cout << "футов \n"  << endl;
};

}

Answer 2

Isn't 0.19 written with a dot?)