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Book Class with Composition

Part of the Object Oriented Programming section of Coddy's JavaScript journey. Lesson 51 of 56.

Challenge

Create Book Class with Composition

Your task:

In the file called Book.js import the Author class at the top
Create and export a Book class with:
- Private fields: #title, #author, #isCheckedOut
- Constructor that takes title and author
- Two getters: title and authorInfo that returns the author's name
In main.js, add the import for Book class

How Composition is Applied Here:

Composition means "has-a" relationship. In our Book class:

Book HAS-AN Author (not "is-an" Author)
The Book contains an Author instance as one of its components
The Author exists separately and can be used by multiple Books
This is composition: building complex objects (Book) from simpler ones (Author)

Try it yourself

import { Author } from './Author.js';

// TODO:  Import the Book class

// Tests
const author = new Author('J.K. Rowling');
const book = new Book('Harry Potter', author);

console.log('Book title:', book.title); // Should output: "Book title: Harry Potter"
console.log('Author:', book.authorInfo); // Should output: "Author: J.K. Rowling"

All lessons in Object Oriented Programming

1Objects & The this Keyword

Quick Review: Objects Adding Methods to Objects Understanding the this Keyword Constructor Functions The new Keyword Recap Challenge

4Methods & Managing State

Methods that modify state Method chaining pattern

7 Inheritance & The extends Key

Inheritance The "is-a" Relationship The extends Keyword The super() Method Inheriting Properties&Methods Recap Challenge

10Polymorphism

What is Polymorphism?Overriding Inherited Methods Using super Recap Challenge

13Composition vs. Inheritance

The "has-a" vs. "is-a"The Limits of Deep Inheritance Building objects

2Organizing Code

What are Modules?Exporting with export Importing with import Default vs. Named Exports

5Encapsulation & Access

Encapsulation Public & Private Class Fields Private Methods Recap Challenge

8Organizing OOP Code

Organize Classes into Modules

11Project: A Shape Renderer

Setup: Shape Class & Export Circle Class Inheritance Overriding & Area Method Static Shape Counter

14Library Management System

Designing the LibraryBook Class with CompositionBook Author Validation

3Classes & Objects

What is a Class?Creating Instances Properties and Methods Recap Challenge

6Project: A Simple Bank Account

BankAccount Class Deposits and Withdrawals Balance as Private Field

9Static Methods & Properties

Class-Level vs. Instance-Level Static Properties Static Utility Methods Recap challenge

12Getters & Setters

The get and set Keywords Computed Properties Validation and Side Effects Recap Challenge

15 Final Challenges

Game Character Builder E-commerce Product System University Management System Smart Home Device System

Practice on your own: Online JavaScript compiler