Check out example codes for "index string c++". It will help you in understanding the concepts better.

Code Example 1

#include <string>
#include <iostream>

int main(){
  //index string by using brackets []
  std::string string = "Hello, World!";
  //assign variable to string index
  char stringindex = string[2];
  
}

Code Example 2

// string::operator[]
#include <iostream>
#include <string>

int main ()
{
  std::string str ("Test string");
  for (int i=0; i<str.length(); ++i)
  {
    std::cout << str[i];
  }
  return 0;
}

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