Segmentation fault (core dumped)

[JasonTay95]

I'm doing a login system via OOP.
here is my code:

header:
#include<string>
using namespace std;

class Login{
	private:
		int option;
		string us,ps,psw;
		
	public:
		string login();
		string setAcc(string us, string psw);
		string setLogin(string us, string ps, string psw);
};


variable:
#include"Login.h"
#include<iostream>
#include<fstream>

string Login::login(){
	using namespace std;
	cout<<"Welcome to Car Renting system"<<endl;
	cout<<"Please choose what you want to do."<<endl;
	cout<<"1 for Login."<<"    "<<"2 for register(if you don't have a account)"<<endl;
	cin>>option;
}

string Login::setAcc(string us, string ps){
	
	using namespace std;
		
  	cout<<"Please key in a username."<<endl;
	cin>>us;
		
	cout<<"Please key in a password."<<endl;
	cin>>ps;
		
	ofstream myfile;
 	myfile.open ((us+".txt").c_str());
 	myfile<< us<<endl;
 	myfile<< ps<<endl;
  	myfile.close();
  	
	 return login();
}

string  Login::setLogin(string us, string ps, string psw){
	
	using namespace std;
	
	cout<<"Please key in your username."<<endl;
	cin>>us;
		 
	cout<<"Please key in your password."<<endl;
	cin>>psw;
		 
	ifstream myfile ((us+".txt").c_str());
	getline (myfile,us) ;
	getline (myfile,ps);
		 	
      	if ( psw ==ps){
			cout<<"Welcome"<<endl;
		}	
  
  		else{
  			cout<<"You have entered a wrong username or password."<<endl;
  			
  		return login();
		}
}

main function:

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

using namespace std;



int main(){
	
	int option;
	string us, ps, psw;
	
	Login Jason;
	
	Jason.login();
		
	if(option==1){
		Jason.setLogin(us, ps, psw);	
	}
	
	else{
		Jason.setAcc(us, ps);
	}
	
	return 0;
}

where was the problem that caused segmentation fault(core dumped) error.

[Peter87]

In login() you forgot to return anything.

In setLogin() you forgot to return something when the keys match.

In main() you are using the option variable without initializing it.

[JasonTay95]

header:
#include<string>
using namespace std;

class Login{
	private:
		int option;
		string us,ps,psw;
		
	public:
		int getLogin(int option);
		string setAcc(string us, string psw);
		string setLogin(string us, string ps, string psw);
};


variable:
#include"Login.h"
#include<iostream>
#include<fstream>

int Login::getLogin(int option){
	cout<<"Welcome to Car Renting system"<<endl;
	cout<<"Please choose what you want to do."<<endl;
	cout<<"1 for Login."<<"    "<<"2 for register(if you don't have a account)"<<endl;
	cin>>option;
	return option;	
}
	


string Login::setAcc(string us, string ps){
	
	using namespace std;
		
  	cout<<"Please key in a username."<<endl;
	cin>>us;
		
	cout<<"Please key in a password."<<endl;
	cin>>ps;
		
	ofstream myfile;
 	myfile.open ((us+".txt").c_str());
 	myfile<< us<<endl;
 	myfile<< ps<<endl;
  	myfile.close();
  	
	return getLogin(option);
}

string  Login::setLogin(string us, string ps, string psw){
	
	using namespace std;
	
	cout<<"Please key in your username."<<endl;
	cin>>us;
		 
	cout<<"Please key in your password."<<endl;
	cin>>psw;
		 
	ifstream myfile ((us+".txt").c_str());
	getline (myfile,us) ;
	getline (myfile,ps);
		 	
      	if ( psw ==ps){
			cout<<"Welcome"<<endl;
			
		return 0;
		}	
  
  		else{
  			cout<<"You have entered a wrong username or password."<<endl;
  			
  		return getLogin(option);
		}
}

main function:

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

using namespace std;

int main(){
	
	int option;
	string us, ps, psw;
	
	Login Jason;
	
	Jason.getLogin(option);
	
	if(option==1){
		Jason.setLogin(us, ps, psw);	
	}
	
	else{
		Jason.setAcc(us, ps);
	}
	
return 0;
}

i have error that cant convert int into string. i knw the reason. but how should i return back to the function int Login::getLogin(int option) so the user can login again after register or entered wrong username/ password......