Creating a function to lowercase a string.

[llllllll]

I have to implement: string tolower(string str) , which lowercases all alphabetic characters in the string.

This code works by itself:

  string str = "HELLO";
  int i = 0;
	char c;
	while (str[i]) {
		c = str[i];
		str[i] = tolower(c);
		cout << str[i];
		i++;
	}

However, it won't work when I implement it with the function definition:

string tolower(string str) {

  int i = 0;
	char c;
	while (str[i]) {
		c = str[i];
		str[i] = tolower(c);
		cout << str[i];
		i++;
	}
}

Then call using: cout << tolower("HELLO");

Thank you for the help.

[MiiNiPaa]

You need to return something from your function as it is declared as returning value. Additionally you do not need to output anything in your function at all.

[llllllll]

Thanks for the advice. I ended up with:

string tolower(string str) {

  int i = 0;
	char c;
	while (str[i]) {
		c = str[i];
		str[i] = tolower(c);
		i++;
	}
return str;
}

But it still isn't working correctly, and I'm not really sure what I should do.

I get this compile error: none of the 2 overloads could convert all the argument types

[Peter87]

It would be more helpful if you posted the full error message.

[llllllll]

Here it is:

error C2665: 'tolower' : none of the 2 overloads could convert all the argument types
1> C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\ctype.h(146): could be 'int tolower(int)'
1> while trying to match the argument list '(const char [6])'

[Peter87]

Make sure your tolower function has been declared before you try to call it.

[llllllll]

I forgot to include the parameters in the prototype -_-
Thank you for the help.