[RESOLVED] Returning a Char from a Function

[Rick Bull]

I'm trying to return a single char from a function, but I'm not doing it right. Can someone tell me how? Here's what I have:

#include <iostream.h>
#include <string>

char show_choice(bool clear_screen = true);

int main()
{
    char    user_choice[1] = "";
    do    //Loop while the users doesn't want to quit
    {
        //Get the user's choice
          user_choice[1] = show_choice();
    } while (strcmp(user_choice, "Q") != 0 && strcmp(user_choice, "q") != 0);
    return 0;
}

char show_choice(bool clear_screen /*= true*/)
{
    //if (clear_screen == true) ;
    
    char user_choice[1] = "";
    do
    {
        cout << "U = Enter web page URI\n" <<
                "O = Options\n" <<
                "H = Help\n" <<
                "Q = Quit\n";
        cout << "Please enter your choice: ";
        cin >> user_choice;
    } while (strcmp(user_choice, "U") != 0 && strcmp(user_choice, "u") != 0 &&
             strcmp(user_choice, "O") != 0 && strcmp(user_choice, "o") != 0 &&
             strcmp(user_choice, "H") != 0 && strcmp(user_choice, "H") != 0 &&
             strcmp(user_choice, "Q") != 0 && strcmp(user_choice, "q") != 0);
    return user_choice[1];
} 

(they need some real C++ highlighting, so it says C++ code: )

[parksie]

char    user_choice[1] = "";

Try just char user_choice = '\0' and compare only the first character (using == rather than strcmp).

[Zaei]

char user_choice;
    do
    {
        cout << "U = Enter web page URI\n" <<
                "O = Options\n" <<
                "H = Help\n" <<
                "Q = Quit\n";
        cout << "Please enter your choice: ";
        cin >> user_choice;
    } while ((user_choice != 'U') && (user_choice != 'u') && (user_choice != 'O') && (user_choice != 'o') &&
(user_choice != 'H') && (user_choice != 'h') &&
(user_choice != 'Q') && (user_choice != 'q'));
    return user_choice;

Should work.

Z.

[Rick Bull]

Thanks for the help guys. It's working now! So what's the difference between using single and double quotes?

[parksie]

Double quotes creates a const char*, i.e. a pointer to a pre-allocated section of memory. Single quotes surround *one* character.

[Rick Bull]

I get ya (I think ). Thanks.

[Zaei]

'a' == 'a' != "a" == |'a'|'\0'|

If that makes sense =).

Z.

[Rick Bull]

Umm, almost! So "a" is just 'a' with a null char at the end?

[parksie]

Yes, but stored elsewhere.

Ok, you have your function:

void function() {
    char a = 'b';
    const char* b = "hello world!";
    char c[] = "another string";
}

There, on the function's stack, there is the character 'b', then a pointer, then enough space to fit in "another string". This is why I made the distinction with const.

The "hello world!" is stored somewhere completely different, all that is kept with the function is a pointer that you cannot change.

You can, of course, modify c as long as you don't change the length

[Rick Bull]

OK I get it now, thanks.