Why Error?

Question

#include <iostream>
#include <cmath>
using namespace std;

int main() {
auto b = 1.95;
//auto c = floor(b*10)%10;
cout<<floor(b*10)%10<<endl;
//cout<<c;
return 0;
}
floor(b) - - int
floor(b*10)--int
floor(b*10)%10--Error
Why?

Answer 1

The type returned from
floor(b*10)
is a double.
The operands on both sides of the modulus operator % need to be of type int.
You can fix it by casting the value returned to an int.
cout << (int)floor(b*10)%10<<endl;