C++ Win32 Problem Retrieving Text From Textbox

[«The Silver Lining»™]

Hi, I have a problem with retrieving text from a textbox, heres the code:

char getuser[50];
                 char getpass[50];
                 int i = 0;

                 ifstream b_file ("users.txt");
           
                 while(!b_file.eof())
                 {
                 b_file >> getuser;
                 b_file >> getpass;
                 i++;
                 }
           
                 b_file.close();
           
                 HWND GetUsername;
                 HWND GetPassword;
                 char username[_MAX_PATH+1];
                 char password[_MAX_PATH+1];

                 GetUsername = GetDlgItem(hwnd, ID_USERNAME);
                 GetWindowText(GetUsername, username, _MAX_PATH);
       
                 GetPassword = GetDlgItem(hwnd, ID_PASSWORD);
                 GetWindowText(GetPassword, password, _MAX_PATH);
                 
                 if(username == getuser && password == getpass)
                 {
                 MessageBox(NULL, "You Are Now Logged On", "Successful Logon", MB_OK);
                 }
                 else
                 {
                 MessageBox(NULL, "Invalid Username Or Password", "Unsuccessful Logon", MB_OK);
                 }

The problem is that it if you put username to a messagebox it does show the value from the textbox but if you try and use the variable in an if statement like i have in my code it doesnt match the other variable. Whats going on?

[Jordan]

if(username == getuser && password == getpass)

This is not doing what you think it is doing because all of these variables are character arrays, not string objects. The string object has overloaded the == operator so it compares all the individual characters like you would think, but a character array is not an object, it's an array of bytes. Arrays are not objects in C++ like in most high level languages used today, they are just raw data. You're actually just comparing the pointers in that if statement which are definitely not the same because they each point to a different set of data. Even if they contained the same strings, they would still be different because their addresses in memory are in different locations.

What you need to use is strcmp().

www.cplusplus.com/reference/clibrary/cstring/strcmp/

[«The Silver Lining»™]

Ah so it would be something like this:

if(strcmp(username, getuser) == 0 && strcmp(password, getpass) == 0)

Thanks for your help

[Jordan]

Yup, that's it exactly. There are several other C-string functions shown on that website that you should take a look at so you are familiar with them.

[«The Silver Lining»™]

Ok thanks for your help

[kokotea]

Thanks