<aside> Properties and instance variables are two fundamental ways to store and manage data in C# classes. Understanding when to use each is crucial for writing maintainable code.

</aside>

💡 Example 1: Using Properties

public class BankAccount
{
    // Auto-implemented properties
    public string AccountNumber { get; private set; }
    public decimal Balance { get; private set; }
    
    // Property with validation
    private string _ownerName;
    public string OwnerName
    {
        get { return _ownerName; }
        set 
        { 
            if (string.IsNullOrEmpty(value))
                throw new ArgumentException("Name cannot be empty");
            _ownerName = value;
        }
    }

    public BankAccount(string accountNumber, string ownerName)
    {
        AccountNumber = accountNumber;
        OwnerName = ownerName;
        Balance = 0;
    }

    public void Deposit(decimal amount)
    {
        if (amount > 0)
            Balance += amount;
    }
}

✨ Properties Key Points:

• 🔐 Properties provide controlled access to data
• ✅ Can include validation logic in getters and setters
• 🔄 Can be read-only (get only), write-only (set only), or both
• 🏗️ Auto-implemented properties create hidden backing fields
• 🔒 Can have different access levels for get and set

🔧 Example 2: Using Instance Variables

public class BankAccount
{
    // Private instance variables
    private string _accountNumber;
    private string _ownerName;
    private decimal _balance;

    public BankAccount(string accountNumber, string ownerName)
    {
        _accountNumber = accountNumber;
        _ownerName = ownerName;
        _balance = 0;
    }

    // Methods to access instance variables
    public string GetAccountNumber()
    {
        return _accountNumber;
    }

    public void SetOwnerName(string name)
    {
        if (string.IsNullOrEmpty(name))
            throw new ArgumentException("Name cannot be empty");
        _ownerName = name;
    }

    public decimal GetBalance()
    {
        return _balance;
    }

    public void Deposit(decimal amount)
    {
        if (amount > 0)
            _balance += amount;
    }
}

🔨 Instance Variables Key Points:

• 📦 Direct field storage without built-in access control
• 🔒 Typically private with public methods for access
• ⚙️ Require explicit getter/setter methods for access control
• 📝 More verbose when implementing access control
• 🏷️ Follow naming convention with underscore prefix

🤔 When to Use Each

✨ Use Properties When:

• You need to validate data before setting values