How to print a double with a comma

Question

In C++ I\'ve got a float/double variable.

When I print this with for example cout the resulting string is period-delimited.

cout << 3.1415 <         


        

Answer 1

This is controlled by your program's locale.

How you set a program's default locale depends on the platform. On POSIX type platforms, it's with the LANG and LC_* environment variables, for instance.

You can force a particular locale -- different from the default -- within a C++ program by calling ios::imbue. Something like this might work:

#include 
cout.imbue(std::locale("German_germany"));

The idea is to force a locale where comma is the decimal separator. You might need to adjust the "German_germany" string to get the behavior you want on your particular platform.