Question

I have global variable. I want to use char data type so I can insert username in it. So far it’s not working.

In main.cpp

#include "Functions.h"

using namespace std;

    char username[50];

int main()
{   
    cout << username;
}

In Functions.h

char username[50];

In login.cpp

#include "Functions.h"

                if(std::strcmp(emp_username, "admin") == 1) {
                    username = "admin";

                }

                else
                {
                    username = emp_username;

                }

What I want to do is to get the employee username and display it in every function. It works with int data type. Only I don’t know how to use it with char. Please help me with this. Thank you.

Answer 1

Don’t use plain character arrays to store strings, use the std::string class:

std::string username;
std::string emp_username;

// Note that this is rather pointless, since it's equivalent to 
//    username = emp_username;
// but I'll leave it as it is to demonstrate how "string" works.
if (emp_username == "admin") {
    username = "admin";
} else {
    username = emp_username;
}

If you have some weird requirement that forces you to use plain arrays, then compare using:

if (std::strcmp(emp_username, "admin") == 0)  // NOT 1

and the contents can’t be assigned using =; you need library functions:

username[sizeof username - 1] = 0;
std::strncpy(username, emp_username, sizeof username);
if (username[sizeof username - 1] != 0) {
    // Whoops! The buffer was too small. Handle the error somehow.
}

Finally, if you must have a global variable (which is nearly always a very bad idea), then you need to declare it extern in the header:

extern std::string username;