Give an example of encapsulation in C#.?

Real-World Example: Bank Account Management

public class BankAccount

private string accountNumber; // private field

private decimal balance; // private field

public string AccountNumber { get { return accountNumber; } } //

read-only

public decimal Balance { get { return balance; } } //

read-only

public BankAccount(string accNum, decimal initialBalance)

accountNumber = accNum;

balance = initialBalance >= 0 ? initialBalance : throw new

ArgumentException("Invalid balance");

public void Deposit(decimal amount)

if(amount > 0) balance += amount;

else throw new ArgumentException("Deposit must be

positive");

public void Withdraw(decimal amount)

if(amount > 0 && amount <= balance) balance -= amount;

else throw new InvalidOperationException("Insufficient

balance");

// Usage

BankAccount myAccount = new BankAccount("ACC123", 1000);

myAccount.Deposit(500); // Balance becomes 1500

myAccount.Withdraw(200); // Balance becomes 1300

Console.WriteLine($"Account: {myAccount.AccountNumber}, Balance:

{myAccount.Balance}");

Explanation:

• accountNumber and balance are private, protecting sensitive data.
• Controlled access via methods ensures data integrity.
• Demonstrates real-world encapsulation in action.

🔹 Section 3: Abstraction – Interview Q&A