Classes and objects in Java - Mini Project: Build & Apply

Classes and Objects

📖 Scenario: You are creating a simple program to manage information about books in a library.

🎯 Goal: Build a Java program that defines a Book class with attributes and creates objects to store book details.

📋 What You'll Learn

Define a class named Book with two attributes: title and author.

Create a variable of type Book named myBook.

Assign values to the title and author attributes of myBook.

Print the book details in the format: Title: [title], Author: [author].

💡 Why This Matters

🌍 Real World

Classes and objects help organize data and behavior in programs, like managing books in a library system.

💼 Career

Understanding classes and objects is essential for software development jobs, especially in object-oriented programming languages like Java.

1

Create the Book class with attributes

Write a public class named Book with two public string attributes: title and author.

Java

public class Book {
    // Your code here
}

Need a hint?

Use public String title; and public String author; inside the class.

2

Create a Book object and assign values

In the Main class, create a Book object named myBook and set myBook.title to "The Alchemist" and myBook.author to "Paulo Coelho".

Java

public class Book {
    public String title;
    public String author;
}

public class Main {
    public static void main(String[] args) {
        // Your code here
    }
}

Need a hint?

Create the object with new Book() and assign values using dot notation.

3

Add a method to display book details

Add a public method named displayInfo inside the Book class that prints the book details in the format: Title: [title], Author: [author].

Java

public class Book {
    public String title;
    public String author;
    // Your code here
}

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

Need a hint?

Use System.out.println inside the method to show the book details.

4

Call the displayInfo method to show book details

In the main method, call the displayInfo method on the myBook object to print the book details.

Java

public class Book {
    public String title;
    public String author;
    public void displayInfo() {
        System.out.println("Title: " + title + ", Author: " + 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?

Call myBook.displayInfo(); to print the details.