change to lowercase character c++

To change a string to lowercase in C++, you can use the tolower function from the <cctype> header. Here are the steps:

1. Include the <cctype> header at the beginning of your code:

#include <cctype>

1. Declare a string variable and initialize it with the string you want to convert:

std::string str = "C++";

1. Loop through each character in the string and convert it to lowercase using the tolower function:

for (char& c : str) {
  c = std::tolower(c);
}

1. Print the lowercase string:

std::cout << str << std::endl;

The tolower function takes a character as input and returns the lowercase version of that character. In the loop, we're using a range-based for loop to iterate through each character in the string. The char& c syntax allows us to modify each character in-place. By calling std::tolower(c), we're converting the character to lowercase. Finally, we print the modified string using std::cout.

Here's the complete code:

#include <iostream>
#include <cctype>

int main() {
  std::string str = "C++";

  for (char& c : str) {
    c = std::tolower(c);
  }

  std::cout << str << std::endl;

  return 0;
}

When you run this code, it will output "c++", which is the lowercase version of the original string "C++".