How to change the values of a string using the index

Overview

A string in C++ is used to store text.

A string variable is one that contains a collection of characters that are enclosed by double quotes " ".

To change the value of a given character of a string in C++, we refer to the index position or the index number of the character using single quotes.

Syntax

Take a look at this simple code:

myString[0] = 'T'

The code above illustrates how to change the value of a string character. The code is simply asking C++ to change the value of a character in the index position 0 of the string variable myString to another value T. This was made possible by the use of square brackets [] and single quotes ' '.

Note: For every character in a string, the index position of the first character is 0, that of the second character is 1, and so on to the last character.

Code example

Now, let’s write a simple code to illustrate how we can use the index position of a character to change the value of the character in a string.

#include <iostream>
#include <string>
using namespace std;
int main() {
  // creation a string
  string mystring = "Hello";
  // to change the 0 index (i.e H) of the string to T
  mystring[0] = 'T';
  cout << mystring;
  return 0;
}

Explanation

We can see from the code above that we are able to change the value of H in Hello to T, making it possible for us to change the string to Tello.

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