cpp string addition code example

Example 1: append string c++

// appending to string
#include <iostream>
#include <string>

int main ()
{
  std::string str;
  std::string str2="Writing ";
  std::string str3="print 10 and then 5 more";

  // used in the same order as described above:
  str.append(str2);                       // "Writing "
  str.append(str3,6,3);                   // "10 "
  str.append("dots are cool",5);          // "dots "
  str.append("here: ");                   // "here: "
  str.append(10u,'.');                    // ".........."
  str.append(str3.begin()+8,str3.end());  // " and then 5 more"
  str.append<int>(5,0x2E);                // "....."

  std::cout << str << '\n';
  return 0;
}

Example 2: concat string in c++

#include <iostream>
#include <sstream>

int main() {
  std::string value = "Hello, " + "world!";
  std::cout << value << std::endl;

  //Or you can use ostringstream and use integers too
  //For example:

  std::ostringstream ss;
  ss << "This is an integer" << 104;
  std::cout << ss.str() << std::endl;
}

Example 3: c++ string concatenation

string first_name = "foo"
string last_name = "bar"
std::cout << first_name + " " + last_name << std::endl;