how do you change a string from uppercase to lowercase

[antonioruns]

I wanted to know how to change a string from uppercase to lower case without a loop. I've been trying to look for a solution online but cant find one. I thought this would work but I keep getting a ‘std::string’ has no member named ‘tolower’ error. please help

  string normalize(string s)
 11 {
 12 
 13  string target(s.tolower());
 14 
 15 
 16 
 17 return target;
 18 }
 19 
 20 
 21 int main()
 22 {
 23 
 24 
 25 
 26   string s = "HELLOW WORLD";
 27 cout<<normalize(s)<<endl;
 28 
 29 return 0;
 30 }

[Ispil]

The tolower function applies to character arrays, not strings. Now, if you want to use tolower with a string, you will need to use std::transform, which is in the algorithm library. Specifically, it would be written as thus:

std::string normalize (string s)
{
    std::transform(s.begin(), s.end(), s.begin(), ::tolower);
    return s;
}

Note that you must #include <algorithm> to use transform.

[antonioruns]

Thanks for the help it worked.

[giblit]

And if you are not allowed to use transform you can loop through each character in the string. Also if you read on the tolower function it takes a parameter of a character and it is not a member function of the string class but from the cctype library. http://www.cplusplus.com/reference/cctype/tolower/?kw=tolower

So the way to do it without the algorithm would be:

for( int i = 0; i < SIZE_OF_STRING; ++i )
{
    some_string[i] = tolower(some_string[i];
}

or you can use iterators I suppose.