Nsryjdtyk

I recently created a simple C++ Login Program (check code below). However, I am not fully convinced unless I can solve the following issues I have in mind. I really need somebody's help with the following:

1. If I run the program for the first time, obviously I must not login successfully because there's no existing account, what can I do so that if I choose login and enter a username and password the program will output "Account does not Exist"




2. I also want the program to detect if I entered a wrong username or password to an existing account




3. How can I add forget password function?

Thank you so much.

#include<iostream>

#include<string>

#include<cstdlib>

#include<fstream>



using namespace std;



int choice;

bool cinfail;

int confirmation;

string username, password, password2;



void MainMenu();



void writetofile(string username){

     ofstream writefile;

     string file = username+".txt";

     writefile.open(file.c_str());

     writefile << password;

     writefile.close();

     MainMenu();

}



void login(){

     system("cls");

     cout<<"Username: "<<endl;

     cin>>username;

     cout<<"Password: "<<endl;

     cin>>password;



     if((username == username) && (password == password2)){

          cout<<"SUCCESSFUL LOGIN!";

     }

     else{

          cout<<"INVALID USERNAME OR PASSWORD!"<<endl;

     }

}



void RegisterPassword(){

     cout<<"Please enter the password: "<<endl;

     cin>>password;

     cout<<"Please reenter your password: "<<endl;

     cin>>password2;



     if(password == password2){

         cin.clear();

         cin.ignore(10000, 'n');

         writetofile(username);

         exit(1);

     }

     else{

          cout<<"Sorry, invalid password. Try again."<<endl;

          RegisterPassword();

     }

     system("cls");

}



void registerme(){

     system("cls");

     cout<<"REGISTER ACCOUNT"<<endl;

     cout<<"Please enter your username: "<<endl;

     getline(cin, username);

     cout<<"nUsername - "" <<username<< ""nConfirm? nn[1] Yesn[2] No"<<endl;

     cin>>confirmation;



     if(confirmation == 1){

         RegisterPassword();

     }

     else{

         cout<<"Sorry, invalid input. Try again"<<endl;

         cin.clear();

         cin.ignore(10000, 'n');

         registerme();

     }

}



void exit(){

     exit(0);

}



void MainMenu(){

     cout<<"SIMPLE LOGIN PROGRAM by RZAMn[1] Loginn[2] Registern[3] Exit"<<endl;

     cin>>choice;



     do{

          cinfail = cin.fail();

          cin.clear();

          cin.getline(10000,'n');



          }while(cinfail == true);{

               switch(choice){

                      case 1:

                           login();

                           break;



                      case 2:

                           registerme();

                           break;



                      case 3:

                           exit();

               }

          }

}



main(){

MainMenu();

}

For any forgotten passwords we would usually send an email asking if it's a legitimate request. You can't do that, maybe save the users date of birth when they login or a secret question. They can use this to enter a new password.

For detecting the wrong password to an existing account:

1. Read all usernames into an array


2. Check the entered username against all of them


3. If the username exists, and the password is wrong you can alert the user.