Creating instances without new keyword in Kotlin - Try It Yourself

Creating instances without new keyword

📖 Scenario: Imagine you are building a simple app to manage books in a library. You want to create book objects to store information about each book.

🎯 Goal: You will create instances of a Book class without using the new keyword, which is not used in Kotlin. You will then print the details of the book.

📋 What You'll Learn

Create a data class called Book with properties title and author

Create an instance of Book without using new

Print the book details using string interpolation

💡 Why This Matters

🌍 Real World

Creating instances without the <code>new</code> keyword is common in Kotlin and many modern languages. It makes code cleaner and easier to read.

💼 Career

Understanding how to create and use class instances is fundamental for Kotlin developers working on Android apps, backend services, or any Kotlin-based projects.

1

Create the Book data class

Create a Kotlin data class called Book with two properties: title of type String and author of type String.

Kotlin

# Your code here

Need a hint?

Use the data class keyword to create a simple class with properties.

2

Create a Book instance

Create a variable called myBook and assign it an instance of Book with the title "The Hobbit" and author "J.R.R. Tolkien". Do not use the new keyword.

Kotlin

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

# Your code here

Need a hint?

In Kotlin, you create instances by calling the class name like a function without new.

3

Access properties of the Book instance

Create a variable called bookTitle and assign it the title property of myBook. Also create a variable called bookAuthor and assign it the author property of myBook.

Kotlin

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

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

# Your code here

Need a hint?

Use dot notation to access properties of an instance.

4

Print the book details

Print the text "Title: The Hobbit, Author: J.R.R. Tolkien" using the variables bookTitle and bookAuthor with string interpolation.

Kotlin

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

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

val bookTitle = myBook.title
val bookAuthor = myBook.author

# Your code here

Need a hint?

Use println and $variableName inside a string to insert variable values.