Data class copy and destructuring in Kotlin - Mini Project: Build & Apply

Data class copy and destructuring

📖 Scenario: You are managing a small library system. Each book has a title, author, and year of publication.

🎯 Goal: You will create a data class for books, make a copy of a book with a changed year, and use destructuring to get the book details.

📋 What You'll Learn

Create a data class called Book with title, author, and year properties

Create an instance of Book called originalBook with exact values

Create a copy of originalBook called updatedBook with the year changed

Use destructuring to get title, author, and year from updatedBook

Print the destructured values in the format: Title: [title], Author: [author], Year: [year]

💡 Why This Matters

🌍 Real World

Data classes and copying are useful when you want to keep original data safe but create modified versions, like updating book info without changing the original record.

💼 Career

Understanding data classes, copying, and destructuring is important for Kotlin developers working on apps that manage data efficiently and clearly.

1

Create the Book data class and originalBook instance

Create a data class called Book with title (String), author (String), and year (Int) properties. Then create a variable called originalBook and set it to Book("The Hobbit", "J.R.R. Tolkien", 1937).

Kotlin

// Create the data class Book and the originalBook instance
// Your code here

Need a hint?

Use data class keyword to create the class. Then create originalBook with the exact values.

2

Create a copy of originalBook with a new year

Create a variable called updatedBook by copying originalBook and changing the year to 1951 using the copy function.

Kotlin

data class Book(val title: String, val author: String, val year: Int)

val originalBook = Book("The Hobbit", "J.R.R. Tolkien", 1937)

// Create updatedBook by copying originalBook with year 1951
// Your code here

Need a hint?

Use originalBook.copy(year = 1951) to create the new book.

3

Destructure updatedBook into variables

Use destructuring to create variables title, author, and year from updatedBook.

Kotlin

data class Book(val title: String, val author: String, val year: Int)

val originalBook = Book("The Hobbit", "J.R.R. Tolkien", 1937)

val updatedBook = originalBook.copy(year = 1951)

// Destructure updatedBook into title, author, and year
// Your code here

Need a hint?

Use val (title, author, year) = updatedBook to get the values.

4

Print the destructured book details

Print the book details using println in this exact format: Title: [title], Author: [author], Year: [year].

Kotlin

data class Book(val title: String, val author: String, val year: Int)

val originalBook = Book("The Hobbit", "J.R.R. Tolkien", 1937)

val updatedBook = originalBook.copy(year = 1951)

val (title, author, year) = updatedBook

// Print the book details in the required format
// Your code here

Need a hint?

Use println with an f-string style using $ to insert variables.