While perform manipulation with character or with string you need to do it with an char  array for string or char variable for a single character.

This is the first way to manipulate the characters with char array.

char greeting[6] = {'H', 'e', 'l', 'l', 'o', '\0'};

This is the way to manipulate the ire string with character array.

char greeting[] = "Hello";

The memory representation of these looks like this.

Actually, we don't place null at the last position of the string t. The C++ compiler automatically place '\0' at the end of the string when it initializes the array.

#include <iostream>

using namespace std;

int main ()
{
   char greeting[6] = {'H', 'e', 'l', 'l', 'o', '\0'};

   cout << "Greeting message: ";
   cout << greeting << endl;

   return 0;
}

We have many built in string functions.