Bank Management System

A lightweight and scalable C++ console application featuring core banking functionalities with structured data storage in JSON and CSV.

📌 Features

✅ Create Accounts (Savings & Current)
✅ View Account Details
✅ Modify Account (Name & Type)
✅ Deposit & Withdraw Money
✅ Delete Account
✅ Save & Load Data in JSON
✅ Export Data to CSV

📜 Table of Contents

1. Installation & Setup
2. Usage Guide
3. File & Directory Structure
4. Code Explanation
5. Data Storage Formats
6. Error Handling
7. Contribution Guidelines
8. License
9. Credits & Authors

⚙️ Installation & Setup

🔹 Prerequisites

• C++ Compiler (GCC, Clang, MSVC, etc.)
• C++17 or later
• JSON Library (nlohmann/json)

🔹 Steps to Run

1️⃣ Clone the Repository:

git clone https://github.com/kreeeesh17/bank-managment-system.git
cd bank-management-system

2️⃣ Compile the Code:

g++ -o bank main.cpp src/user.cpp -std=c++17 -Iinclude

OR

make

3️⃣ Run the Program:

./bank

OR

make run

4️⃣ Clear the Database and Executables after use:

make clean

📖 Usage Guide

1️⃣ Create an Account

• The system prompts for Name and Account Type (Savings/Current).
• Generates a unique account number based on the date and a counter.

2️⃣ View Account Details

1. Enter your account number.
2. See Number, Name, Balance, and Type.

3️⃣ Deposit Money

1. Enter account number.
2. Enter deposit amount.
3. Balance updates automatically.

4️⃣ Withdraw Money

1. Enter account number.
2. Enter withdrawal amount.
3. If sufficient balance → Success.
4. If not → Error message.

5️⃣ Modify Account

1. Enter account number.
2. Change Name & Account Type.
3. Data is saved instantly.

6️⃣ Delete Account

1. Enter account number.
2. Confirm deletion.
3. Account is removed from JSON file.

7️⃣ Export Accounts to CSV

1. Select CSV export option.
2. Data saved in `data/accounts.csv`.

📁 File & Directory Structure

Bank Management System/
│
├── .gitignore                 # Specifies files and directories that should be ignored by Git
├── LICENSE                    # Open-source MIT license for the project
├── README.md                  # Project description, installation, usage, and details
├── Makefile                   # Instructions for building and cleaning the project
├── build/                     # Directory for future build artifacts (currently empty)
│
├── data/                       # Directory containing data files (accounts.json, accounts.csv)
│   ├── accounts.json
│   └── accounts.csv
│
├── include/                   # Header files
│   ├── json.hpp                # JSON library (external)
│   └── user.h                  # User class definition
│
├── src/                        # Source files
│   └── user.cpp                # User class implementation
│
├── main.cpp                    # Main program entry point
└── bin/                        # (Optional) Directory for executables (not used directly in this setup)

🛠️ Code Explanation

🔹 User Class (user.h & user.cpp)

• Private Members
  • account_number, user_name, account_balance, account_type
• Public Methods
  • createAccount() → Takes user input & generates account.
  • displayAccount() → Prints details of the account.
  • deposit(double amount) → Adds money to the account.
  • withdraw(double amount) → Deducts money from the account.
  • modifyAccount() → Changes name & type of the account.
  • deleteAccount() → Removes account data from the storage.
  • toJson() → Converts the user object to a JSON format.
  • saveToJson() → Saves all accounts to data/accounts.json.
  • loadFromJson() → Reads account data from JSON and updates the users list.
  • exportToCSV() → Exports all account data to data/accounts.csv.

🔹 getCurrentDate() Function

• Returns the current date in YYYYMMDD format, which is used to generate unique account numbers by combining it with a static counter.

🔹 Static Counter

• A static counter is used to generate unique account numbers. This ensures that each account number is distinct and incremented automatically with every new account creation.

📂 Data Storage Formats

🔹 JSON File Format (data/accounts.json)

[
    {
        "account_number": "0000202502261",
        "user_name": "John Doe",
        "account_balance": 1000.50,
        "account_type": "Savings"
    }
]

🔹 CSV File Format (data/accounts.csv)

Account Number,Name,Balance,Type
0000202502261,John Doe,1000.50,Savings

❌ Error Handling

✔ Invalid Inputs → If incorrect data is entered, prompts reappear for correction.
✔ Insufficient Balance → Withdrawals are blocked if the account has insufficient funds.
✔ File Errors → If JSON/CSV files fail to open, errors are displayed.

🔧 Industry Readiness & Best Practices

• Memory Efficiency
  ✅ Uses a global vector<User> to store all users, avoiding redundant data loading.
  ✅ A static counter for unique account number generation ensures efficient handling without conflicts.

• Modern C++ Practices
  ✅ Structured serialization of objects using nlohmann/json.
  ✅ RAII principles: Destructor ensures proper memory management.
  ✅ No raw pointers—uses smart memory management.

• Scalability & Maintainability
  ✅ Enum-based account types: Future-proof design with extendable account types.
  ✅ Global unordered_map<Type, std::string> allows for efficient lookup of account types.
  ✅ The code avoids dependency on compiler-specific features, ensuring broader compatibility.

• Performance Not Sacrificed
  ✅ Efficient handling of large datasets using JSON for storage.
  ✅ Optimized file I/O with stream-based handling of file operations.

👥 Contribution Guidelines

✅ Fork the repository.
✅ Make changes in a separate branch.
✅ Submit a pull request (PR) with a proper description of your changes.

📜 License

This project is open-source under the MIT License.

🏆 Credits & Authors

👨‍💻 Developed By: Kreesh Modi
🎓 IIT Kharagpur | Mechanical Engineering