Correct use of std::cout.precision() - not printing trailing zeros

Question

I see many questions about the precision number for floating point numbers but specifically I want to know why this code

#include <iostream> #include <stdlib.h> int main() {   int a = 5;   int b = 10;   std::cout.precision(4);   std::cout << (float)a/(float)b << "\n";   return 0; } 

shows 0.5? I expect to see 0.5000. Is it because of the original integer data types?

Answer 1

#include <iostream> #include <stdlib.h> #include <iomanip> int main() {   int a = 5;   int b = 10;   std::cout << std::fixed;   std::cout << std::setprecision(4);   std::cout << (float)a/(float)b << "\n";   return 0; } 

You need to pass std::fixed manipulator to cout in order to show trailing zeroes.