How do you append an int to a string in C++? [duplicate]

Question

With C++11, you can write:

#include <string>     // to use std::string, std::to_string() and "+" operator acting on strings 

int i = 4;
std::string text = "Player ";
text += std::to_string(i);

Well, if you use cout you can just write the integer directly to it, as in

std::cout << text << i;

The C++ way of converting all kinds of objects to strings is through string streams. If you don't have one handy, just create one.

#include <sstream>

std::ostringstream oss;
oss << text << i;
std::cout << oss.str();

Alternatively, you can just convert the integer and append it to the string.

oss << i;
text += oss.str();

Finally, the Boost libraries provide boost::lexical_cast, which wraps around the stringstream conversion with a syntax like the built-in type casts.

#include <boost/lexical_cast.hpp>

text += boost::lexical_cast<std::string>(i);

This also works the other way around, i.e. to parse strings.

printf("Player %d", i);

(Downvote my answer all you like; I still hate the C++ I/O operators.)

:-P

These work for general strings (in case you do not want to output to file/console, but store for later use or something).

boost.lexical_cast

MyStr += boost::lexical_cast<std::string>(MyInt);

String streams

//sstream.h
std::stringstream Stream;
Stream.str(MyStr);
Stream << MyInt;
MyStr = Stream.str();

// If you're using a stream (for example, cout), rather than std::string
someStream << MyInt;

For the record, you can also use a std::stringstream if you want to create the string before it's actually output.

cout << text << " " << i << endl;