程序输出中的C++字符奇怪

我正在为学校创建一个C++ATM程序，我正在利用这个项目作为开始学习语言的机会。 我正在尝试将银行帐户输出到以下格式的文本文件：

First Last  
CardNumber  
PinNumber  
Balance

最初它输出很好，然后我开发了一堆新方法等。 我没有更改任何与输出银行帐户有关的原始代码，但现在它输出很奇怪。

我的输出最终是：

First Last  
random letter or symbol  
PinNumber  
blank  

这是我创建新银行帐户的代码：

AccountHandler.h

#include <iostream>
#include <string>
using namespace std;
struct bankAccount //Create a new bank account type
{
string name;
string cardNum;
string balance;
string pin;
};

class AccountHandler
{
public:
    AccountHandler();
    ~AccountHandler();
    void withdraw(struct bankAccount acc, string amount);
    void deposit(struct bankAccount acc);
    int checkBalance(struct bankAccount acc);
    void createAccount();

};

帐户处理程序.cpp

void AccountHandler::createAccount() //creates a new bank account and stores in accounts.txt
{
ofstream accounts;
struct bankAccount newAcc;
string first, last;
string tempPin1, tempPin2;
if (!accounts.is_open())
{
    accounts.open("accounts.txt", ofstream::app);
}
std::cout << "Thank you for choosing to bank with ATM406!nn";
std::cout << "Please enter the name for the account: ";
std::cin >> first >> last;
newAcc.name = first + " " + last;
while (true)
{
    std::cout << "nPlease enter a 4-digit pin for security: ";
    std::cin >> tempPin1;
    std::cout << "nPlease re-enter your 4-digit pin for validation: ";
    std::cin >> tempPin2;
    if (tempPin1 == tempPin2) //PINS MATCH
    {
        newAcc.pin = tempPin1;
        break;
    }
    else //PINS DO NOT MATCH
    {
        std::cout << "The pins did not match!" << std::endl;
    }
}
//GENERATE A RANDOM 4-DIGIT NUMBER FOR CARDNUM
srand(time(NULL));
newAcc.cardNum = rand() % 9000 + 1000;

//STORE ACCOUNT IN FORMAT: NAMEnCARDNUMnPINnBALANCE
accounts << newAcc.name << "n" << newAcc.cardNum << "n" 
    << newAcc.pin << "n" << newAcc.balance << "n";
accounts.close();
std::cout << "nAccount created with name: " << newAcc.name << "  pin: " << newAcc.pin
    << ". Card number: " << newAcc.cardNum << "nnn";

}

谢谢！