Convert a number to a string with specified length in C++

c++ integer stdstring
Degvik picture Degvik · Oct 22, 2008 · Viewed 60.2k times · Source

I have some numbers of different length (like 1, 999, 76492, so on) and I want to convert them all to strings with a common length (for example, if the length is 6, then those strings will be: '000001', '000999', '076492').

In other words, I need to add correct amount of leading zeros to the number.

int n = 999;
string str = some_function(n,6);
//str = '000999'

Is there a function like this in C++?

Answer

xtofl picture xtofl · Oct 22, 2008

or using the stringstreams:

#include <sstream>
#include <iomanip>

std::stringstream ss;
ss << std::setw(10) << std::setfill('0') << i;
std::string s = ss.str();

I compiled the information I found on arachnoid.com because I like the type-safe way of iostreams more. Besides, you can equally use this code on any other output stream.

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