How to concatenate a std::string and an int?

Question

I thought this would be really simple but it\'s presenting some difficulties. If I have

std::string name = \"John\";
int age = 21;

How do I

Answer 1

If you have Boost, you can convert the integer to a string using boost::lexical_cast(age).

Another way is to use stringstreams:

std::stringstream ss;
ss << age;
std::cout << name << ss.str() << std::endl;

A third approach would be to use sprintf or snprintf from the C library.

char buffer[128];
snprintf(buffer, sizeof(buffer), "%s%d", name.c_str(), age);
std::cout << buffer << std::endl;

Other posters suggested using itoa. This is NOT a standard function, so your code will not be portable if you use it. There are compilers that don't support it.