Comma Formatting for numbers in C++

Question

I\'m needing help in adding commas to the number the user enters, some guidance or help would be appreciated. So far I have it where i store the first three digits and the l

Answer 1

EDIT: I have two solutions. first without playing with numbers (recommended) and second (division). first solution is:

#include 
#include 
#include 
#include 
using namespace std;

struct my_facet : public std::numpunct{
        explicit my_facet(size_t refs = 0) : std::numpunct(refs) {}
        virtual char do_thousands_sep() const { return ','; }
        virtual std::string do_grouping() const { return "\003"; }
};

/*
 * 
 */
int main(int argc, char** argv) {

    cout<<"before. number 5000000: "<<5000000<

before. number 5000000: 5000000
after. number 5000000: 5,000,000

and again as before. number 5000000: 5000000

RUN SUCCESSFUL (total time: 54ms)

and second (not recommended) is :

double f = 23.43;
std::string f_str = std::to_string(f);

or this

int a = 1;
stringstream ss;
ss << a;
string str = ss.str();

Then you can use string::substr() string::find() string::find_first_of() and similar methods to modify and format your string.
a similar topic

---

If you really want (have to) divide: (I think my version is cleaner & more efficient than the others)

unsigned long long userInput;
    std::stringstream ss,s0;
    std::string nr;
        std::cout << "Enter a long long number: " << std::endl;
        std::cin >> userInput;
        int input=userInput;
        int digits;

        while(input>999){
            input=input/1000;
            digits=userInput-input*1000;
            int mdigits=digits;
            while(mdigits<100){s0<<"0";mdigits*=10;}
            std::string s=ss.str();
            ss.str("");
            ss<<","<

Enter a long long number: 12345678 Your Number: 12;345;12,345,678