如何用C++实现银行管理系统的类

Question

我正在使用 C++ 制作一个简单的银行管理系统，但我遇到了一些问题。我刚刚了解了课程，我知道它可以用来实现账户余额、存款、取款等功能，但我遇到了困难。我不明白该怎么做。有人可以简单地向我解释一下吗，我是初学者。

#include <iostream>
#include <iomanip>
#include <time.h>
using namespace std;

//This function gives a Bank Account class

class BankAccount {
  double account_balance;

public:
  void set_balance(double initial_balance = 0.0) {
    account_balance = initial_balance;
  }

  void deposit(double deposit_amount)
  {
    account_balance += deposit_amount;
  }

}

int main() {
  int Option1 = 1, Option2 = 2, Option3 = 3, Option4 = 4, account_Options;
  string user_Name, user_Password;
  srand(time(NULL));
  int account_No = rand() % 10000000000 + 1000000000;
  cout << "Welcome to Scam Bank \n" // Welcome message and Options to choose New account or Proceed to an account.
          "1.Open New Account \n"
          "2.Continue to my Account \n"
          "How would you like to proceed?...\n";
  cin >> account_Options;
  if (account_Options == Option1)
  { // Option for New user.
    cout << "Welcome, New user \n";
    cout << "Please type your First name:... \n";
    cin >> user_Name;
    cout << "Please type a password:... \n";
    cin >> user_Password;
    cout << "Hi " << user_Name << ", Thanks for creating an accout with us!" << endl;
    cout << "Your account Number is: " << account_No;
    while (true)
    {
      double deposit_amount;
      cout << "How would you like to procceed?" << endl;
      cout << "1.Deposit \n"
              "2.Withdraw \n"
              "3.Check Balance \n"
              "4.Exit \n";
      cin >> account_Options;

      const int option1= 1, option2 = 2, option3 = 3, option4 = 4;
      switch (account_Options) {
        case option1:
          cout << "How much would you like to deposit" << endl;
          cin >> deposit_amount;
          cout << "You have successfully deposit $" <<  << " to your balance." << endl;
          break;
        case option2:
          int withdraw;
          cout << "How much would you like to withdraw? \n";
          cin >> withdraw;
          cout << "You have withdrawn: " << withdraw << endl;
          break;
        case option3:
          cout << "Your current balance is: " << newAccount.bank_balance << endl;
          break;
        case option4:
          cout << "Thank you for using Scam Bank!" << endl;
          return 0;
          break;
        default:
          cout << "Invalid Option" << endl;
          break;
      }
    }

  }  return 0;
}

我已经尝试过没有类的存款、余额和取款功能，但它不会针对任何新输入进行更新。例如，如果我存入 200 美元，余额将为 200 美元，当我再存入 200 美元时，余额仍为 200 美元，而不是更新后的 400 美元。

Answer 1

 It seems like you have in the BankAccount class declaration, you're missing a semicolon after the class definition.
 And also in the deposit logic, you're not updating the balance correctly.

 Here is the fully updated code 
#include <iostream>
#include <iomanip>
#include <cstdlib> 
#include <ctime>   
using namespace std;


class BankAccount {
private:
    double account_balance;

public:
    void set_balance(double initial_balance = 0.0) {
        account_balance = initial_balance;
     }

    void deposit(double deposit_amount) {
         account_balance += deposit_amount;
    }

    void withdraw(double withdraw_amount) {
        if (withdraw_amount <= account_balance) {
            account_balance -= withdraw_amount;
         } else {
            cout << "Insufficient funds!" << endl;
        }
     }

     double get_balance() {
        return account_balance;
    }
 };

 int main() {
    int Option1 = 1, Option2 = 2, Option3 = 3, Option4 = 4, 
account_Options;
    string user_Name, user_Password;
    srand(time(NULL));
    int account_No = rand() % 10000000000 + 1000000000;
    cout << "Welcome to Scam Bank \n" 
         << "1.Open New Account \n"
         << "2.Continue to my Account \n"
         << "How would you like to proceed?...\n";
     cin >> account_Options;
    if (account_Options == Option1) {
        cout << "Welcome, New user \n";
        cout << "Please type your First name:... \n";
        cin >> user_Name;
        cout << "Please type a password:... \n";
        cin >> user_Password;
        cout << "Hi " << user_Name << ", Thanks for creating an account 
with us!" << endl;
        cout << "Your account Number is: " << account_No << endl;
    
        BankAccount newAccount;
        double deposit_amount, withdraw_amount;

        while (true) {
            cout << "How would you like to proceed?" << endl
             << "1.Deposit \n"
             << "2.Withdraw \n"
             << "3.Check Balance \n"
             << "4.Exit \n";
        cin >> account_Options;

        switch (account_Options) {
            case 1:
                cout << "How much would you like to deposit? ";
                cin >> deposit_amount;
                newAccount.deposit(deposit_amount); 
                cout << "You have successfully deposited $" << 
 deposit_amount << " to your balance." << endl;
                break;
            case 2:
                cout << "How much would you like to withdraw? ";
                cin >> withdraw_amount;
                newAccount.withdraw(withdraw_amount); 
                break;
            case 3:
                cout << "Your current balance is: $" << fixed << 
  setprecision(2) << newAccount.get_balance() << endl;
                break;
            case 4:
                cout << "Thank you for using Scam Bank!" << endl;
                return 0;
            default:
                cout << "Invalid Option" << endl;
                break;
        }
          }
     }
   return 0;
  }

Thank You