How to convert std::string to lower case?

Question

I want to convert a `std::string` to lowercase. I am aware of the function `tolower()`, however in the past I have had issues with this function and it is hardly ideal anyway as use with a `std::string` would require iterating over each character. Is there an alternative which works 100% of the time?

Answer 1

There is no alternative that I am aware of. However, it is very simple to create a function that does this. If you would like to make a string lowercase in C++. You can use this code. You can just add 32 to the ascii value of a lower case letter to get an uppercase letter.

void lowercase (string &string1)

{

string s = "";

  for(int i = 0; i < string1.length(); i++)

  {

    if (string1.at(i) >= 65 && string1.at(i) <= 90)

{

s = s + char(string1.at(i) +32);

}

else

{

s = s+string1.at(i);

}

  }

  string1 = s;

}