#include <iostream>
#include <string>
#include <vector>
#include <cctype>

using std::cout;
using std::cin;
using std::string;
using std::vector;

class Account {
private:
string name, password;
double balance;
int account;

public:
Account(string accountName, string password, double initialBalance, int accountNumber)
    : name(accountName), password(password), balance(initialBalance), 
account(accountNumber) {}

void deposit(double amount) {
    if (amount > 0) {
        balance += amount;
        cout << "Deposit successful. n";
    }
}

bool transfer(int acc_to, int amount) {
    if (amount > balance || amount < 0) {
        cout << "Invalid amount!";
        return false;
    }
    balance -= amount;
    return true;
}

void changeName(string newName) {
    name = newName;
    cout << "Name changed successful. n";
}

void withdraw(double amount) {
    if (amount <= balance) {
        balance -= amount;
        cout << "Withdraw successful. n";
    }
    else {
        cout << "Insufficient Funds. n";
    }
}

void display() {
    cout << "Account: " << name << "nBalance: $" << balance << "nAccount Number: " << 
account << "n";
}

void set_id(int input) {
    account = input;
}

int get_id() {
    return account;
}

string const& getPass() {
    return password;
}

string const& getName() {
    return name;
}

};

void clear() {
std::cin.clear();
std::cin.ignore(std::numeric_limits<std::streamsize>::max(), 'n');
}

int main() {
string name, password, newName;
vector<Account> accounts;
double initialDeposit, amount;
int choice, logInChoice, accountNumber = 0, index = 0;
bool logged_in = false, account_has_digit = false, running = true;

while (running) {
    while (logged_in == false) {
        vector<string> loginMenu{ "Please log in or create an account.", "1. Create An 
Account", "2. Log In" };
        for (auto& option : loginMenu) {
            cout << option << "n";
        }

        cout << "Enter Choice: ";
        if (!(cin >> logInChoice) || logInChoice < 1 || logInChoice > 2) {
            clear();
            cout << "Invalid Input! n";
            continue;
        }

        switch (logInChoice) {
        case 1:

            cout << "Enter an account name: ";
            cin >> name;

            for (auto& each : name) {
                if (isdigit(each)) {
                    account_has_digit = true;
                    break;
                }
            }

            if (account_has_digit) {
                cout << "Invalid Input! Please use only characters. n";
                clear();
                continue;
            }

            cout << "Enter a Password: ";
            cin >> password;

            cout << "Enter initial deposit: n";
            cin >> initialDeposit;

            accountNumber++;

            accounts.emplace_back(name, password, initialDeposit, accountNumber);
            continue;
        case 2:
            cout << "Enter your account name: ";
            cin >> name;

            cout << "Enter a Password: ";
            cin >> password;

            for (auto& acc : accounts) {
                if ((acc.getName() == name && acc.getPass() == password) && index <= 
accounts.size()) {
                    logged_in = true;
                    break;
                }
                index++;
            }
            }

            do {
                vector<string> menu{ "1. Deposit", "2. Withdraw", "3. Display Account", 
"4. Transfer Money", "5. Change Name", "6. Log Out", "7. Exit" };

                for (auto& option : menu) {
                    cout << option << "n";
                }
                cout << "Enter choice: ";
                cin >> choice;

                switch (choice) {
                case 1:
                    cout << "Enter deposit amount: ";
                    cin >> amount;
                    accounts[index].deposit(amount);
                    break;
                case 2:
                    cout << "Enter withdraw amount: ";
                    cin >> amount;
                    accounts[index].withdraw(amount);
                    break;
                case 3:
                    accounts[index].display();
                    break;
                case 4:
                    int transferAcc, transferAmount;
                    cout << "Input an account number to transfer to: ";
                    cin >> transferAcc;

                    cout << "nInput an amount: ";
                    cin >> transferAmount;

                    if (accounts[index].transfer(transferAcc, transferAmount) == true) 
{
                        for (auto& acc : accounts) {
                            if (acc.get_id() == transferAcc) {
                                acc.deposit(transferAmount);
                            }
                        }
                        cout << "Transfer successful. n";
                        break;
                    }

                case 5:
                    cout << "Enter new name: ";
                    cin >> newName;
                    accounts[index].changeName(newName);
                    break;
                case 6:
                    logged_in = false;
                    index = 0;
                    break;
                case 7:
                    logged_in = false;
                    running = false;
                    break;
                default:
                    cout << "Invalid choice. n";
                    break;
                }
            } while (logged_in);
        }
    return 0;
}
}

This is my first use of classes in C++. A banking system with no persistence that can handle multiple accounts, login/logout, money transfer, and some error handling. Havnt messed much with password security. Just looking for general feedback on code structure and pointers on anything done wrong. Thanks