Question

For examples, with 4 digits, convert 0 to “0000”; and 12 to “0012”.

Any good way in c++?

Sorry not making it clear, my compiler doesn’t support snprintf, and I want a function like

std::string ToString(int value, int digitsCount);

Answer 1

Maybe something like this

#include <iostream>
#include <iomanip>
#include <sstream>

using namespace std;

string ToString(int value,int digitsCount)
{
    ostringstream os;
    os<<setfill('0')<<setw(digitsCount)<<value;
    return os.str();
}

int main()
{
    cout<<ToString(0,4)<<endl;
    cout<<ToString(12,4)<<endl;
}