main.cpp

//                                                  Banking System
#include <iostream>
#include <fstream>
#include <cstdlib>

using namespace std;
int main()
{

    string Username;
    string Paswword;
    int x = 0; // the option the user will choose
    int y = 0; // withdrawl money
    int r = 0;
    double balance;
    bool running = true;
    ifstream inputfile("balance.txt");
    inputfile >> balance;
    inputfile.close();

    cout << "                    Good afternoon Sir/mam \n Username : ";
    cin >> Username;
    system("cls");
    cout << "password : ";
    cin >> Paswword;

    if (Username == "Username" && Paswword == "admin")//change it if you need to
    {
        while (running)
        {
            system("cls");
            cout << "Welcome to your Account " << Username << endl;
            cout << "Please choose one of the following options : \n";
            cout << "1.Check account balance. \n2.Withdraw Money. \n3.Insert Money.\n4.Exit\n> ";
            cin >> x;
            switch (x)
            {
            case 1:
                system("cls");
                cout << "Your balance is " << balance << endl;
                break;

            case 2:
                cout << "You currently have " << balance << "\nHow much Do you want to withdraw?\n>";
                cin >> y;
                if (y > balance)
                {
                    cout << "You are too broke\n";
                }
                else
                {
                    balance = balance - y;
                    cout << "Done! You currently have " << balance << endl;
                }
                break;

            case 3:
                cout << "How much money are you willing to insert? : ";
                cin >> r;
                balance = balance + r;
                cout << "Done! You currently have " << balance << endl;
                break;
                case 4:
                cout<<"exiting..\n";
                running = false ;
                break;
                default :
                cout << "Invalid option!\n";
                ;
                break;
           ; }system("pause");
        }
    }
    else
    {
        cout << "wrong credentials !" << endl;
        system("pause");
    }
    fstream outfile("Balance.txt");
    outfile << balance;
    outfile.close();
    return 0;

}