Access modifiers (public, private, internal) in C Sharp (C#) - Mini Project: Build & Apply

Access Modifiers in C#

📖 Scenario: You are creating a simple class to represent a bank account. You want to control how the account's balance can be accessed and changed by using access modifiers.

🎯 Goal: Build a C# class BankAccount that uses public, private, and internal access modifiers to protect and expose data correctly.

📋 What You'll Learn

Create a class called BankAccount with a private field for balance

Add a public method to deposit money

Add an internal method to display the balance

Add a public method to withdraw money with balance check

💡 Why This Matters

🌍 Real World

Access modifiers help protect sensitive data and control how parts of a program interact, like keeping bank account balances safe.

💼 Career

Understanding access modifiers is essential for writing secure and maintainable code in professional software development.

1

Create the BankAccount class with a private balance field

Create a class called BankAccount with a private decimal field named balance initialized to 0.

C Sharp (C#)

class BankAccount
{
    // Your code here
}

Need a hint?

Use private decimal balance = 0m; inside the class.

2

Add a public method to deposit money

Add a public method called Deposit that takes a decimal parameter amount and adds it to the private balance.

C Sharp (C#)

class BankAccount
{
    private decimal balance = 0m;

    // Your code here
}

Need a hint?

Use public void Deposit(decimal amount) and add amount to balance.

3

Add an internal method to display the balance

Add an internal method called DisplayBalance that returns the current balance as a decimal.

C Sharp (C#)

class BankAccount
{
    private decimal balance = 0m;

    public void Deposit(decimal amount)
    {
        balance += amount;
    }

    // Your code here
}

Need a hint?

Use internal decimal DisplayBalance() to return balance.

4

Add a public method to withdraw money with balance check and print the balance

Add a public method called Withdraw that takes a decimal amount. It should subtract amount from balance only if balance is enough. Then, create a BankAccount object, deposit 100, withdraw 30, and print the balance using DisplayBalance().

C Sharp (C#)

class BankAccount
{
    private decimal balance = 0m;

    public void Deposit(decimal amount)
    {
        balance += amount;
    }

    internal decimal DisplayBalance()
    {
        return balance;
    }

    // Your code here
}

// Your code here

Need a hint?

Use public void Withdraw(decimal amount) with an if to check balance. Then create BankAccount object, deposit 100, withdraw 30, and print balance.