Class definition in Java - Mini Project: Build & Apply

Class definition

📖 Scenario: You are creating a simple program to represent a book in a library system. Each book has a title and an author.

🎯 Goal: Build a Java class called Book with two fields: title and author. Then create an object of this class and print its details.

📋 What You'll Learn

Create a class named Book

Add two String fields: title and author

Create an object of Book with title "The Alchemist" and author "Paulo Coelho"

Print the book's title and author using System.out.println

💡 Why This Matters

🌍 Real World

Classes like Book help organize data about real things in programs, such as books in a library or products in a store.

💼 Career

Understanding how to define classes and create objects is a fundamental skill for any Java developer.

1

Create the Book class with fields

Write a Java class named Book with two String fields called title and author.

Java

// Your code here

Need a hint?

Use public class Book {} and declare two variables inside.

2

Create a Book object with values

Create a Book object named myBook. Set its title to "The Alchemist" and author to "Paulo Coelho".

Java

public class Book {
    String title;
    String author;
}

// Your code here

Need a hint?

Create the object with new Book() and assign values to fields.

3

Add code to print the book details

Inside the main method, add two System.out.println statements to print myBook.title and myBook.author.

Java

public class Book {
    String title;
    String author;
}

public class Main {
    public static void main(String[] args) {
        Book myBook = new Book();
        myBook.title = "The Alchemist";
        myBook.author = "Paulo Coelho";
        // Your code here
    }
}

Need a hint?

Use System.out.println to show the values stored in the object.

4

Run the program to see the output

Run the program and observe the output. It should print the book's title and author on separate lines.

Java

public class Book {
    String title;
    String author;
}

public class Main {
    public static void main(String[] args) {
        Book myBook = new Book();
        myBook.title = "The Alchemist";
        myBook.author = "Paulo Coelho";
        System.out.println(myBook.title);
        System.out.println(myBook.author);
    }
}

// Run the program

Need a hint?

The program should print exactly the title and author on two lines.