Methods that operate on state in C Sharp (C#) - Mini Project: Build & Apply

Methods that operate on state

📖 Scenario: You are creating a simple bank account program. The account has a balance that changes when you deposit or withdraw money.

🎯 Goal: Build a class with methods that change the account balance and show the current balance.

📋 What You'll Learn

Create a class called BankAccount with a private balance variable.

Add a method Deposit that adds money to balance.

Add a method Withdraw that subtracts money from balance.

Add a method GetBalance that returns the current balance.

Create an instance of BankAccount and use the methods to change and show the balance.

💡 Why This Matters

🌍 Real World

Bank accounts, game scores, or any object that keeps track of changing information use methods to update and read their state.

💼 Career

Understanding how to write methods that operate on an object's state is essential for software development, especially in object-oriented programming.

1

Create the BankAccount class with a balance variable

Create a class called BankAccount with a private integer variable balance set to 0.

C Sharp (C#)

class BankAccount
{
    // Your code here
}

Need a hint?

Use class BankAccount and inside it declare private int balance = 0;.

2

Add Deposit and Withdraw methods

Add a public method Deposit that takes an integer amount and adds it to balance. Add a public method Withdraw that takes an integer amount and subtracts it from balance.

C Sharp (C#)

class BankAccount
{
    private int balance = 0;

    // Your code here
}

Need a hint?

Write two methods: Deposit adds amount to balance, Withdraw subtracts amount from balance.

3

Add GetBalance method

Add a public method GetBalance that returns the current balance as an integer.

C Sharp (C#)

class BankAccount
{
    private int balance = 0;

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

    public void Withdraw(int amount)
    {
        balance -= amount;
    }

    // Your code here
}

Need a hint?

Write a method GetBalance that returns the value of balance.

4

Create an instance and show the balance

Create an instance of BankAccount called account. Call Deposit(100) and Withdraw(30) on account. Then print the result of account.GetBalance().

C Sharp (C#)

class BankAccount
{
    private int balance = 0;

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

    public void Withdraw(int amount)
    {
        balance -= amount;
    }

    public int GetBalance()
    {
        return balance;
    }
}

// Your code here

Need a hint?

Create account, call Deposit(100), Withdraw(30), then print account.GetBalance().