__clone for object copying in PHP - Mini Project: Build & Apply

__clone for object copying

📖 Scenario: Imagine you have a Book object representing a book in a library system. You want to create a copy of this book object to make changes without affecting the original.

🎯 Goal: You will create a Book class with a __clone method to properly copy the object. Then, you will clone an instance and show that the original and the clone are separate objects.

📋 What You'll Learn

Create a Book class with title and author properties

Add a __clone method to the Book class

Create an instance of Book with specific title and author

Clone the Book instance into a new variable

Print the titles and authors of both original and cloned objects

💡 Why This Matters

🌍 Real World

Cloning objects is useful when you want to create a copy of an item to change or test without affecting the original, like copying a book record in a library system.

💼 Career

Understanding object cloning helps in software development when managing data copies, avoiding bugs from shared references, and implementing features like undo or templates.

1

Create the Book class with properties

Create a class called Book with public properties title and author. Then create an object called originalBook with title set to "1984" and author set to "George Orwell".

PHP

<?php

// Create the Book class and originalBook object here

Need a hint?

Define the class with public properties. Then create an object and assign the exact title and author.

2

Add the __clone method to the Book class

Add a __clone method inside the Book class that prints "Cloning book..." when an object is cloned.

PHP

title = "1984";
$originalBook->author = "George Orwell";

Need a hint?

The __clone method runs automatically when you clone an object. Use echo inside it.

3

Clone the originalBook object

Create a new variable called clonedBook and assign it a clone of originalBook using the clone keyword.

PHP

title = "1984";
$originalBook->author = "George Orwell";

// Clone originalBook into clonedBook

Need a hint?

Use the clone keyword to copy the object.

4

Print titles and authors of both books

Print the title and author of originalBook and clonedBook using echo. Format each line as: "Original: 1984 by George Orwell" and "Clone: 1984 by George Orwell".

PHP

title = "1984";
$originalBook->author = "George Orwell";

$clonedBook = clone $originalBook;

// Print titles and authors of both books

Need a hint?

Use echo with the exact format and include a newline \n at the end of each line.