Controlling the printing of trailing zeros and decimal points for floating-point values. : float output « Data Types « C++ Tutorial

1. C++ Tutorial
2. Data Types
3. float output

#include <iostream>
#include <iomanip>
#include <cmath>

using std::cout;
using std::endl;
using std::ios;

int main()
{      
   cout << "Before setting the ios::showpoint flag\n"
        << "9.9900 prints as: " << 9.9900 
        << "\n9.9000 prints as: " << 9.9000
        << "\n9.0000 prints as: " << 9.0000
        << "\n\nAfter setting the ios::showpoint flag\n";
   cout.setf( ios::showpoint );
   cout << "9.9900 prints as: " << 9.9900 
        << "\n9.9000 prints as: " << 9.9000
        << "\n9.0000 prints as: " << 9.0000 << endl;
   return 0;
}