Getter seems to crash the program even with 0 errors

Question

im new in the C++ world and coding in general, just started studying getters and setters and made areally simple exercise to practice them, the build seems to have 0 errors and 2 minor warnings, however, when I try to use a function to return a private variable and print it, it simply crashes the program, however, if i use the last function I made "getAccount()" It seems to work just fine.

After some poking, it seems like the problem is with the getter functions, just calling them crashes the program, here's the code:

main.cpp

#include <iostream>
#include "Person.h"
using namespace std;

int main()
{
    User user;
    user.setUser("someuser");
    user.setPassw("somepassword");

    cout << user.getPassw() << endl;
    cout << user.getUser() << endl;

    user.getAccount();
}

Person.h

#define PERSON_H
#include <iostream>

using namespace std;

class User
{
   private:
        string username;
        string password;
    public:
        string setUser(string usernm);
        string setPassw(string pass);
        string getUser();
        string getPassw();
        void getAccount();


};

#endif // PERSON_H

Person.cpp

#include <iostream>
#include "Person.h"

using namespace std;

string User::setUser(string usernm){
    usernm = username;
}

string User::setPassw(string pass){
    pass = password;
}

string User::getUser(){
    return username;
}

string User::getPassw(){
    return password;
}

void User::getAccount(){
    cout << "Account is:" << endl;
    cout << "Username: " + username << endl;
    cout << "Password: " + password << endl;
}

I suggest you to do some rubber-duck debugging. Pay attention to what `pass = password` does — 463035818_is_not_an_ai, May 25 '20 at 08:38
Site note: Never do `using namespace std;` in the global namespace in header files. — Ted Lyngmo, May 25 '20 at 08:38
btw there are errors, but I don't understand how they can cause a crash — 463035818_is_not_an_ai, May 25 '20 at 08:39
Another side note: You said "2 minor warnings". Warnings are the first things you should look at if the program crashes and no error message is generated. They are probably related to your problem. So put them into your question too (even though you already got an answer that probably solves your problem) — wychmaster, May 25 '20 at 08:46

Ted Lyngmo · Accepted Answer · 2020-05-25T08:43:51.720

3

Not all functions declared to return values actually return values so you have Undefined Behaviour and anything could happen.

Example:

string User::setUser(string usernm){
    usernm = username;
    // should return a string here
}

string User::setPassw(string pass){
    pass = password;
    // should return a string here
}

Apart from that, you assign usernm and pass when you should assign username and password so the set operations does not set the member variables.

edited May 25 '20 at 08:43

answered May 25 '20 at 08:41

Ted Lyngmo

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3

nice catch, I checked the getters but missed the setters – 463035818_is_not_an_ai May 25 '20 at 08:42
3

I missed this, I guess the '2 minor warnings` are about exactly this issue. Never ignore warnings! – john May 25 '20 at 08:42
Thank you! I managed to solve the issue after adding the return values to those functions, it seems I really need to study the basics of functions and the return statement again. – Enzen May 25 '20 at 13:34
@Enzen You are welcome. If you don't want the functions to return anything, declare them `void`, like: `void setUser(string usernm);` Such a function does not return a value. – Ted Lyngmo May 25 '20 at 13:36
1

After changing the functions to void the program works as intended, thanks! – Enzen May 25 '20 at 14:04

Getter seems to crash the program even with 0 errors

1 Answers1