🏗 ️ Classes in TypeScript: Object-Oriented Programming Basics

🎯 Introduction

Welcome to the exciting world of Object-Oriented Programming with TypeScript classes! 🎉 Think of classes as blueprints for creating objects - like a cookie cutter that shapes delicious cookies! 🍪

Classes help you organize your code into reusable, structured components that model real-world entities. Whether you’re building a game 🎮, an e-commerce app 🛒, or a social media platform 📱, classes are your best friend for creating maintainable code.

By the end of this tutorial, you’ll be confidently creating classes that make your fellow developers say “Wow, this code is so clean and organized!” 🌟

Let’s dive into the wonderful world of TypeScript classes! 🏊‍♂️

📚 Understanding Classes

🤔 What are Classes?

Classes are like templates or blueprints for creating objects 🏗️. Think of them as:

• 🍪 Cookie cutters: The class is the cutter, objects are the cookies
• 🏠 House blueprints: The class is the blueprint, instances are actual houses
• 🚗 Car factory: The class defines how to make cars, instances are individual cars

In TypeScript, classes combine:

• 📊 Data (properties) - what the object has
• ⚡ Behavior (methods) - what the object can do
• 🔒 Encapsulation - controlling access to data

💡 Why Use Classes?

Here’s why developers love classes:

1. Code Organization 📁: Group related data and functions together
2. Reusability ♻️: Create multiple instances from one blueprint
3. Encapsulation 🔒: Hide internal details, expose clean interfaces
4. Inheritance 👥: Share common functionality between related classes
5. Type Safety 🛡️: TypeScript ensures your classes are used correctly

Real-world example: A User class can represent users in your app, with properties like name and email, and methods like login() and updateProfile() 👤.

🔧 Basic Class Syntax

📝 Your First Class

Let’s create a simple class to understand the basics:

// 🎮 A simple Player class for a game
class Player {
  // 📊 Properties (what the player has)
  name: string;
  level: number;
  health: number;
  
  // 🏗️ Constructor (how to create a player)
  constructor(name: string) {
    this.name = name;
    this.level = 1;        // 🌟 Starting level
    this.health = 100;     // ❤️ Full health to start
  }
  
  // ⚡ Methods (what the player can do)
  levelUp(): void {
    this.level++;
    this.health = 100;     // 🩹 Full heal on level up!
    console.log(`🎉 ${this.name} reached level ${this.level}!`);
  }
  
  takeDamage(damage: number): void {
    this.health -= damage;
    console.log(`💥 ${this.name} took ${damage} damage! Health: ${this.health}`);
    
    if (this.health <= 0) {
      console.log(`💀 ${this.name} has been defeated!`);
    }
  }
  
  // 📊 Getter method
  getStatus(): string {
    return `👤 ${this.name} - Level ${this.level} (${this.health}❤️)`;
  }
}

// 🚀 Creating instances (actual players)
const hero = new Player("Aragorn");
const mage = new Player("Gandalf");

console.log(hero.getStatus());  // 👤 Aragorn - Level 1 (100❤️)
hero.levelUp();                 // 🎉 Aragorn reached level 2!
hero.takeDamage(30);           // 💥 Aragorn took 30 damage! Health: 70

💡 Key Concepts:

• class keyword defines the blueprint
• constructor() runs when creating new instances
• this refers to the current instance
• Properties store data, methods define behavior

💡 Practical Examples

🛒 Example 1: Shopping Cart System

Let’s build a real-world shopping cart:

// 🛍️ Product interface for type safety
interface Product {
  id: string;
  name: string;
  price: number;
  emoji: string;
}

// 📝 Cart item with quantity
interface CartItem {
  product: Product;
  quantity: number;
}

// 🛒 Shopping Cart class
class ShoppingCart {
  // 📊 Private properties (internal data)
  private items: CartItem[] = [];
  private customerName: string;
  
  // 🏗️ Constructor
  constructor(customerName: string) {
    this.customerName = customerName;
    console.log(`🛒 New cart created for ${customerName}!`);
  }
  
  // ➕ Add item to cart
  addItem(product: Product, quantity: number = 1): void {
    // 🔍 Check if item already exists
    const existingItem = this.items.find(item => item.product.id === product.id);
    
    if (existingItem) {
      existingItem.quantity += quantity;
      console.log(`📈 Updated ${product.emoji} ${product.name} quantity to ${existingItem.quantity}`);
    } else {
      this.items.push({ product, quantity });
      console.log(`✅ Added ${quantity}x ${product.emoji} ${product.name} to cart`);
    }
  }
  
  // ➖ Remove item from cart
  removeItem(productId: string): void {
    const index = this.items.findIndex(item => item.product.id === productId);
    
    if (index !== -1) {
      const removedItem = this.items.splice(index, 1)[0];
      console.log(`🗑️ Removed ${removedItem.product.emoji} ${removedItem.product.name} from cart`);
    } else {
      console.log(`❌ Product not found in cart`);
    }
  }
  
  // 💰 Calculate total price
  getTotal(): number {
    return this.items.reduce((total, item) => {
      return total + (item.product.price * item.quantity);
    }, 0);
  }
  
  // 📋 Display cart contents
  displayCart(): void {
    console.log(`\n🛒 ${this.customerName}'s Cart:`);
    console.log('='.repeat(30));
    
    if (this.items.length === 0) {
      console.log('📭 Your cart is empty');
      return;
    }
    
    this.items.forEach(item => {
      const total = item.product.price * item.quantity;
      console.log(`${item.product.emoji} ${item.product.name} x${item.quantity} - $${total.toFixed(2)}`);
    });
    
    console.log('─'.repeat(30));
    console.log(`💰 Total: $${this.getTotal().toFixed(2)}`);
  }
  
  // 🧹 Clear cart
  clearCart(): void {
    this.items = [];
    console.log(`🧹 Cart cleared for ${this.customerName}`);
  }
  
  // 🚀 Checkout process
  checkout(): void {
    if (this.items.length === 0) {
      console.log('❌ Cannot checkout empty cart');
      return;
    }
    
    console.log(`\n🎉 Processing checkout for ${this.customerName}...`);
    this.displayCart();
    console.log(`✅ Order placed successfully! Thank you, ${this.customerName}! 🙏`);
    this.clearCart();
  }
}

// 🛍️ Sample products
const products: Product[] = [
  { id: '1', name: 'TypeScript Book', price: 29.99, emoji: '📘' },
  { id: '2', name: 'Mechanical Keyboard', price: 149.99, emoji: '⌨️' },
  { id: '3', name: 'Coffee Mug', price: 12.99, emoji: '☕' },
  { id: '4', name: 'Stress Ball', price: 7.99, emoji: '🟡' }
];

// 🚀 Let's go shopping!
const cart = new ShoppingCart("Alice");

cart.addItem(products[0], 2);     // 2 books
cart.addItem(products[1]);        // 1 keyboard
cart.addItem(products[2], 3);     // 3 mugs

cart.displayCart();
cart.removeItem('2');             // Remove keyboard
cart.displayCart();
cart.checkout();

🎵 Example 2: Music Player Class

Let’s create a feature-rich music player:

// 🎵 Song interface
interface Song {
  id: string;
  title: string;
  artist: string;
  duration: number; // in seconds
  genre: string;
  emoji: string;
}

// 🎶 Music Player class
class MusicPlayer {
  private playlist: Song[] = [];
  private currentSongIndex: number = -1;
  private isPlaying: boolean = false;
  private volume: number = 50; // 0-100
  private shuffleMode: boolean = false;
  private repeatMode: 'none' | 'one' | 'all' = 'none';
  
  // 📊 Player stats
  private totalPlayTime: number = 0;
  
  constructor() {
    console.log('🎵 Music Player initialized! Ready to rock! 🎸');
  }
  
  // ➕ Add song to playlist
  addSong(song: Song): void {
    this.playlist.push(song);
    console.log(`✅ Added ${song.emoji} "${song.title}" by ${song.artist}`);
  }
  
  // ▶️ Play current song
  play(): void {
    if (this.playlist.length === 0) {
      console.log('❌ No songs in playlist! Add some music first 🎵');
      return;
    }
    
    if (this.currentSongIndex === -1) {
      this.currentSongIndex = 0;
    }
    
    this.isPlaying = true;
    const song = this.playlist[this.currentSongIndex];
    console.log(`▶️ Now playing: ${song.emoji} "${song.title}" by ${song.artist}`);
    this.displayProgress();
  }
  
  // ⏸️ Pause playback
  pause(): void {
    if (this.isPlaying) {
      this.isPlaying = false;
      console.log('⏸️ Playback paused');
    } else {
      console.log('❌ Music is not playing');
    }
  }
  
  // ⏹️ Stop playback
  stop(): void {
    this.isPlaying = false;
    console.log('⏹️ Playback stopped');
  }
  
  // ⏭️ Next song
  next(): void {
    if (this.playlist.length === 0) return;
    
    if (this.shuffleMode) {
      this.currentSongIndex = Math.floor(Math.random() * this.playlist.length);
    } else {
      this.currentSongIndex = (this.currentSongIndex + 1) % this.playlist.length;
    }
    
    if (this.isPlaying) {
      this.play();
    }
  }
  
  // ⏮️ Previous song
  previous(): void {
    if (this.playlist.length === 0) return;
    
    this.currentSongIndex = this.currentSongIndex <= 0 
      ? this.playlist.length - 1 
      : this.currentSongIndex - 1;
    
    if (this.isPlaying) {
      this.play();
    }
  }
  
  // 🔀 Toggle shuffle
  toggleShuffle(): void {
    this.shuffleMode = !this.shuffleMode;
    const status = this.shuffleMode ? 'ON' : 'OFF';
    console.log(`🔀 Shuffle mode: ${status}`);
  }
  
  // 🔁 Cycle repeat mode
  cycleRepeat(): void {
    const modes: ('none' | 'one' | 'all')[] = ['none', 'one', 'all'];
    const currentIndex = modes.indexOf(this.repeatMode);
    const nextIndex = (currentIndex + 1) % modes.length;
    this.repeatMode = modes[nextIndex];
    
    const emojis = { none: '➡️', one: '🔂', all: '🔁' };
    console.log(`${emojis[this.repeatMode]} Repeat mode: ${this.repeatMode}`);
  }
  
  // 🔊 Set volume
  setVolume(level: number): void {
    this.volume = Math.max(0, Math.min(100, level));
    const volumeBar = '█'.repeat(Math.floor(this.volume / 10));
    console.log(`🔊 Volume: ${this.volume}% [${volumeBar}]`);
  }
  
  // 📊 Display current status
  displayStatus(): void {
    console.log('\n🎵 Music Player Status');
    console.log('='.repeat(25));
    
    if (this.currentSongIndex >= 0) {
      const song = this.playlist[this.currentSongIndex];
      const status = this.isPlaying ? '▶️ Playing' : '⏸️ Paused';
      console.log(`${status}: ${song.emoji} "${song.title}"`);
      console.log(`🎤 Artist: ${song.artist}`);
      console.log(`🎭 Genre: ${song.genre}`);
    }
    
    console.log(`📚 Playlist: ${this.playlist.length} songs`);
    console.log(`🔊 Volume: ${this.volume}%`);
    console.log(`🔀 Shuffle: ${this.shuffleMode ? 'ON' : 'OFF'}`);
    console.log(`🔁 Repeat: ${this.repeatMode}`);
  }
  
  // 📋 Show playlist
  showPlaylist(): void {
    console.log('\n📚 Current Playlist:');
    console.log('='.repeat(30));
    
    this.playlist.forEach((song, index) => {
      const current = index === this.currentSongIndex ? '▶️ ' : '   ';
      const duration = `${Math.floor(song.duration / 60)}:${(song.duration % 60).toString().padStart(2, '0')}`;
      console.log(`${current}${song.emoji} "${song.title}" - ${song.artist} (${duration})`);
    });
  }
  
  // 📊 Private helper method
  private displayProgress(): void {
    console.log('🎵 ████████████████████ 100%');
  }
}

// 🎵 Sample songs
const songs: Song[] = [
  { id: '1', title: 'Bohemian Rhapsody', artist: 'Queen', duration: 355, genre: 'Rock', emoji: '👑' },
  { id: '2', title: 'Billie Jean', artist: 'Michael Jackson', duration: 294, genre: 'Pop', emoji: '🕺' },
  { id: '3', title: 'Hotel California', artist: 'Eagles', duration: 391, genre: 'Rock', emoji: '🏨' },
  { id: '4', title: 'Shape of You', artist: 'Ed Sheeran', duration: 234, genre: 'Pop', emoji: '💃' }
];

// 🚀 Let's play some music!
const player = new MusicPlayer();

// Add songs to playlist
songs.forEach(song => player.addSong(song));

// Control playback
player.showPlaylist();
player.play();
player.setVolume(75);
player.toggleShuffle();
player.next();
player.displayStatus();

🚀 Advanced Class Features

🔒 Access Modifiers

Control who can access your class members:

class BankAccount {
  public accountHolder: string;     // ✅ Accessible everywhere
  private balance: number;          // 🔒 Only within this class
  protected accountNumber: string;  // 👥 This class and subclasses
  
  constructor(holder: string, initialBalance: number) {
    this.accountHolder = holder;
    this.balance = initialBalance;
    this.accountNumber = this.generateAccountNumber();
  }
  
  // 🔒 Private method - internal use only
  private generateAccountNumber(): string {
    return 'ACC-' + Math.random().toString(36).substr(2, 9).toUpperCase();
  }
  
  // ✅ Public method - safe interface
  public deposit(amount: number): void {
    if (amount > 0) {
      this.balance += amount;
      console.log(`💰 Deposited $${amount}. New balance: $${this.balance}`);
    }
  }
  
  // ✅ Public method with validation
  public withdraw(amount: number): boolean {
    if (amount > 0 && amount <= this.balance) {
      this.balance -= amount;
      console.log(`💸 Withdrew $${amount}. Remaining balance: $${this.balance}`);
      return true;
    } else {
      console.log('❌ Insufficient funds or invalid amount');
      return false;
    }
  }
  
  // ✅ Safe way to check balance
  public getBalance(): number {
    return this.balance;
  }
}

const account = new BankAccount("John Doe", 1000);
account.deposit(500);           // ✅ Works
console.log(account.getBalance()); // ✅ Works
// console.log(account.balance);   // ❌ Error: private property

🏗️ Static Members

Class-level properties and methods:

class MathUtils {
  // 📊 Static properties - shared by all instances
  static readonly PI = 3.14159;
  static readonly E = 2.71828;
  
  // 🔧 Static methods - utility functions
  static add(a: number, b: number): number {
    return a + b;
  }
  
  static multiply(a: number, b: number): number {
    return a * b;
  }
  
  static circleArea(radius: number): number {
    return MathUtils.PI * radius * radius;
  }
  
  // 📈 Statistics helper
  static average(numbers: number[]): number {
    if (numbers.length === 0) return 0;
    const sum = numbers.reduce((total, num) => total + num, 0);
    return sum / numbers.length;
  }
}

// 🚀 Use static methods without creating instances
console.log(`📐 Circle area: ${MathUtils.circleArea(5)}`);
console.log(`📊 Average: ${MathUtils.average([1, 2, 3, 4, 5])}`);
console.log(`🥧 Pi value: ${MathUtils.PI}`);

⚠️ Common Pitfalls and Solutions

😱 Pitfall 1: Forgetting ‘this’ keyword

class Counter {
  private count: number = 0;
  
  // ❌ Wrong - missing 'this'
  incrementWrong(): void {
    count++; // ❌ Error: 'count' is not defined
  }
  
  // ✅ Correct - using 'this'
  increment(): void {
    this.count++; // ✅ Works!
    console.log(`Count: ${this.count}`);
  }
}

🤯 Pitfall 2: Not initializing properties

class Student {
  name: string;      // ❌ Not initialized
  age: number;       // ❌ Not initialized
  grades: number[] = []; // ✅ Initialized
  
  constructor(name: string, age: number) {
    this.name = name;  // ✅ Initialize in constructor
    this.age = age;    // ✅ Initialize in constructor
  }
}

🔒 Pitfall 3: Exposing internal state

// ❌ Bad - exposes internal array
class BadTodoList {
  public items: string[] = [];
}

// ✅ Good - controls access
class GoodTodoList {
  private items: string[] = [];
  
  addItem(item: string): void {
    this.items.push(item);
  }
  
  getItems(): readonly string[] {
    return [...this.items]; // Return copy
  }
}

🛠️ Best Practices

1. 🎯 Single Responsibility: Each class should have one clear purpose
2. 🔒 Encapsulation: Keep internal details private
3. 📝 Clear Naming: Use descriptive class and method names
4. 🏗️ Constructor Logic: Keep constructors simple and focused
5. ⚡ Method Size: Keep methods small and focused
6. 📊 Immutability: Consider readonly properties where appropriate

🧪 Hands-On Exercise

🎯 Challenge: Build a Library Management System

Create a comprehensive library system using classes:

📋 Requirements:

• 📚 Book class with title, author, ISBN, and availability
• 👤 Member class with name, ID, and borrowed books
• 🏛️ Library class to manage books and members
• 📊 Track borrowing history and due dates
• 🔍 Search functionality for books and members

🚀 Bonus Points:

• Add late fee calculation
• Implement reservation system
• Create different member types (student, adult, premium)

💡 Solution

// 📚 Book class
class Book {
  readonly isbn: string;
  readonly title: string;
  readonly author: string;
  readonly genre: string;
  private isAvailable: boolean = true;
  private borrowedBy: string | null = null;
  private dueDate: Date | null = null;
  
  constructor(isbn: string, title: string, author: string, genre: string) {
    this.isbn = isbn;
    this.title = title;
    this.author = author;
    this.genre = genre;
  }
  
  // 📊 Get book status
  getStatus(): 'available' | 'borrowed' {
    return this.isAvailable ? 'available' : 'borrowed';
  }
  
  // 📅 Get due date if borrowed
  getDueDate(): Date | null {
    return this.dueDate;
  }
  
  // 👤 Get who borrowed it
  getBorrower(): string | null {
    return this.borrowedBy;
  }
  
  // 📖 Borrow book
  borrow(memberId: string, dueDate: Date): boolean {
    if (this.isAvailable) {
      this.isAvailable = false;
      this.borrowedBy = memberId;
      this.dueDate = dueDate;
      return true;
    }
    return false;
  }
  
  // 🔄 Return book
  return(): void {
    this.isAvailable = true;
    this.borrowedBy = null;
    this.dueDate = null;
  }
  
  // 📋 Book info
  getInfo(): string {
    const status = this.isAvailable ? '✅ Available' : '❌ Borrowed';
    return `📚 "${this.title}" by ${this.author} (${this.genre}) - ${status}`;
  }
}

// 👤 Library Member class
class LibraryMember {
  readonly memberId: string;
  readonly name: string;
  readonly email: string;
  private borrowedBooks: string[] = []; // ISBNs
  private joinDate: Date;
  
  constructor(memberId: string, name: string, email: string) {
    this.memberId = memberId;
    this.name = name;
    this.email = email;
    this.joinDate = new Date();
  }
  
  // 📚 Get borrowed books
  getBorrowedBooks(): readonly string[] {
    return [...this.borrowedBooks];
  }
  
  // 📖 Borrow a book
  borrowBook(isbn: string): void {
    this.borrowedBooks.push(isbn);
  }
  
  // 🔄 Return a book
  returnBook(isbn: string): void {
    const index = this.borrowedBooks.indexOf(isbn);
    if (index !== -1) {
      this.borrowedBooks.splice(index, 1);
    }
  }
  
  // 📊 Member info
  getInfo(): string {
    return `👤 ${this.name} (ID: ${this.memberId}) - ${this.borrowedBooks.length} books borrowed`;
  }
}

// 🏛️ Library Management System
class Library {
  private books: Map<string, Book> = new Map();
  private members: Map<string, LibraryMember> = new Map();
  private borrowingPeriodDays: number = 14;
  
  // 📚 Add book to library
  addBook(book: Book): void {
    this.books.set(book.isbn, book);
    console.log(`✅ Added book: ${book.getInfo()}`);
  }
  
  // 👤 Register new member
  registerMember(member: LibraryMember): void {
    this.members.set(member.memberId, member);
    console.log(`✅ Registered member: ${member.getInfo()}`);
  }
  
  // 📖 Borrow book
  borrowBook(memberId: string, isbn: string): boolean {
    const member = this.members.get(memberId);
    const book = this.books.get(isbn);
    
    if (!member) {
      console.log(`❌ Member ${memberId} not found`);
      return false;
    }
    
    if (!book) {
      console.log(`❌ Book ${isbn} not found`);
      return false;
    }
    
    if (book.getStatus() === 'borrowed') {
      console.log(`❌ Book "${book.title}" is already borrowed`);
      return false;
    }
    
    // Calculate due date
    const dueDate = new Date();
    dueDate.setDate(dueDate.getDate() + this.borrowingPeriodDays);
    
    // Process borrowing
    book.borrow(memberId, dueDate);
    member.borrowBook(isbn);
    
    console.log(`📖 ${member.name} borrowed "${book.title}"`);
    console.log(`📅 Due date: ${dueDate.toDateString()}`);
    return true;
  }
  
  // 🔄 Return book
  returnBook(memberId: string, isbn: string): boolean {
    const member = this.members.get(memberId);
    const book = this.books.get(isbn);
    
    if (!member || !book) {
      console.log('❌ Member or book not found');
      return false;
    }
    
    if (book.getBorrower() !== memberId) {
      console.log('❌ This book was not borrowed by this member');
      return false;
    }
    
    // Process return
    book.return();
    member.returnBook(isbn);
    
    console.log(`✅ ${member.name} returned "${book.title}"`);
    return true;
  }
  
  // 🔍 Search books
  searchBooks(query: string): Book[] {
    const results: Book[] = [];
    
    for (const book of this.books.values()) {
      if (book.title.toLowerCase().includes(query.toLowerCase()) ||
          book.author.toLowerCase().includes(query.toLowerCase()) ||
          book.genre.toLowerCase().includes(query.toLowerCase())) {
        results.push(book);
      }
    }
    
    return results;
  }
  
  // 📊 Display library stats
  displayStats(): void {
    console.log('\n🏛️ Library Statistics');
    console.log('='.repeat(25));
    console.log(`📚 Total books: ${this.books.size}`);
    console.log(`👥 Total members: ${this.members.size}`);
    
    let availableBooks = 0;
    let borrowedBooks = 0;
    
    for (const book of this.books.values()) {
      if (book.getStatus() === 'available') {
        availableBooks++;
      } else {
        borrowedBooks++;
      }
    }
    
    console.log(`✅ Available books: ${availableBooks}`);
    console.log(`📖 Borrowed books: ${borrowedBooks}`);
  }
  
  // 📋 List all books
  listBooks(): void {
    console.log('\n📚 Library Catalog:');
    console.log('='.repeat(30));
    
    for (const book of this.books.values()) {
      console.log(book.getInfo());
      if (book.getStatus() === 'borrowed') {
        const member = this.members.get(book.getBorrower()!);
        const dueDate = book.getDueDate()!;
        console.log(`   📅 Due: ${dueDate.toDateString()} (${member?.name})`);
      }
    }
  }
}

// 🚀 Let's build our library!
const library = new Library();

// 📚 Add some books
const books = [
  new Book('978-0134685991', 'Effective TypeScript', 'Dan Vanderkam', 'Programming'),
  new Book('978-1491927632', 'Programming TypeScript', 'Boris Cherny', 'Programming'),
  new Book('978-0596517748', 'JavaScript: The Good Parts', 'Douglas Crockford', 'Programming'),
  new Book('978-0321125217', 'Domain-Driven Design', 'Eric Evans', 'Software Design')
];

books.forEach(book => library.addBook(book));

// 👥 Register members
const members = [
  new LibraryMember('MEM001', 'Alice Johnson', '[email protected]'),
  new LibraryMember('MEM002', 'Bob Smith', '[email protected]'),
  new LibraryMember('MEM003', 'Carol Davis', '[email protected]')
];

members.forEach(member => library.registerMember(member));

// 📖 Test borrowing
library.borrowBook('MEM001', '978-0134685991');
library.borrowBook('MEM002', '978-1491927632');

// 📊 Display current state
library.displayStats();
library.listBooks();

// 🔍 Search functionality
console.log('\n🔍 Search results for "TypeScript":');
const searchResults = library.searchBooks('TypeScript');
searchResults.forEach(book => console.log(book.getInfo()));

🎓 Key Takeaways

Congratulations! You’ve mastered TypeScript classes! Here’s what you can now do:

• ✅ Create classes with properties and methods 🏗️
• ✅ Use constructors to initialize objects properly 🔧
• ✅ Apply access modifiers for proper encapsulation 🔒
• ✅ Build real-world applications with OOP principles 🌟
• ✅ Organize code into reusable, maintainable structures 📁

Remember: Classes are your building blocks for creating amazing applications! 🚀

🤝 Next Steps

Amazing work! 🎉 You’ve unlocked the power of TypeScript classes!

Here’s your learning path forward:

1. 💻 Practice with the library management exercise above
2. 🏗️ Try building your own class-based project
3. 📚 Next tutorial: Class Properties and Methods - Building Class Members
4. 🌟 Share your class designs with the community!

Remember: Great applications start with well-designed classes. Keep building, keep learning! 🚀

Happy coding! 🎉🏗️✨