Question

        #include <iostream>

                int main()
                {
                    char username[15];
                    char password[15];


                    std::cout << "Hello, please login to continue your action.<Max 15 Char>" << std::endl;
                    std::cout << "Username: ";
                    std::cin >> username;
                    std::cout << "Password: ";
                    std::cin >> password;

                    if (username == "User" && password == "qwerty")
                    {
                        std::cout << "Hello, creator.";
                    }
                    else 
                    {
                        std::cout << "Invalid Login";
                    }
/*23 row*/          std::cout << std::endl << std::endl << "Username=" <<username << std::endl << "Password=" << password;

                    std::cout << std::endl << std::endl << "Press Enter to close the window . . . ";
                    std::cin.clear();
                    std::cin.sync();
                    std::cin.get();
                }

When i type correct it should say Hello Creator but it only goes to invalid i thinked maybe char stores only 1 char thats why at 23 row i taked look what is stored in char username and pasword but everything is fine. Why then it takes Else {…} sentence?

Answer 1

There are two types of strings in C++. The kind you are using for username and password are old-style C strings. They are basically a sequence of characters in memory, terminated by a special character '\0'. Since they come from old C, you can not use things like comparison or assignment operators on them.

To compare two old-style C string you have to use the strcmp function:

if (strcmp(username, "user") == 0)
{
    // username == "user"
}

A better solution is to use the new C++ string class: std::string instead, as it has lot more functionality built in. For example handling comparison.