Print integer with thousands and millions separator

Question

Got a question about printing Integers with thousands/millions separator.

I got a Textfile where i got Country, City,Total Population.

I have to read in the

Answer 1

imbue() the output stream with a locale that has the desired separator. For example:

#include 
#include 

int main()
{
    // imbue the output stream with a locale.
    int i = 45749785;
    std::cout << i << "\n";

    std::cout.imbue(std::locale(""));
    std::cout << i << "\n";
}

Output on my machine (and online demo):

45749785
45,749,785

As commented, and answered, by James Kanze imbue the input stream also to read the separated int values without manually modifying the input.

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See Stroustrop's Appendix D: Locales for a detailed overview of locales.