how to add to string c++ 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: c++ append a char to a string

// string::operator+=
#include <iostream>
#include <string>

int main ()
{
  std::string name ("John");
  std::string family ("Smith");
  name += " K. ";         // c-string
  name += family;         // string
  name += '\n';           // character

  std::cout << name;
  return 0;
}

Example 3: string insert c++

// inserting into a string
#include <iostream>
#include <string>

int main ()
{
  std::string str="to be question";
  std::string str2="the ";
  std::string str3="or not to be";
  std::string::iterator it;

  // used in the same order as described above:
  str.insert(6,str2);                 // to be (the )question
  str.insert(6,str3,3,4);             // to be (not )the question
  str.insert(10,"that is cool",8);    // to be not (that is )the question
  str.insert(10,"to be ");            // to be not (to be )that is the question
  str.insert(15,1,':');               // to be not to be(:) that is the question
  it = str.insert(str.begin()+5,','); // to be(,) not to be: that is the question
  str.insert (str.end(),3,'.');       // to be, not to be: that is the question(...)
  str.insert (it+2,str3.begin(),str3.begin()+3); // (or )

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

Example 4: appending string in c++

#include<iostream>
#include <string>
int main() {
	//"Ever thing inside these double quotes becomes const char array"
//	std::string namee = "Caleb" +"Hello";//This will give error because adding const char array to const char array 
	std::string namee = "Caleb";
	namee += " Hello";//This will work because adding a ptr to a actual string
	std::cout << namee << std::endl;// output=>Caleb Hello
//You can also use the below
	std::string namee2 = std::string("Caleb")+" Hello";// This will work because constructor will convert const char array  to string, adding a ptr to string
	std::cout << namee2 << std::endl;// output=>Caleb Hello
	std::cin.get();
}