Object interaction in C++ - Mini Project: Build & Apply

Object interaction

📖 Scenario: You are creating a simple program to manage a library. The library has books, and each book has a title and an author. You want to show how two objects, Library and Book, can work together.

🎯 Goal: Build two classes, Book and Library, where the Library holds a list of Book objects. You will add books to the library and then print the details of all books in the library.

📋 What You'll Learn

Create a class Book with two public string members: title and author.

Create a class Library with a public vector of Book objects called books.

Add a method addBook to Library that takes a Book object and adds it to books.

Add a method printBooks to Library that prints all books with their titles and authors.

In main(), create a Library object, add two Book objects with exact titles and authors, then print all books.

💡 Why This Matters

🌍 Real World

Managing collections of objects is common in software like libraries, stores, or contact lists. This project shows how objects can hold and manage other objects.

💼 Career

Understanding object interaction is key for software development jobs, especially when designing systems with multiple related data types.

1

Create the Book class

Create a class called Book with two public string members: title and author. Then create two Book objects named book1 and book2 with these exact values: book1.title = "1984", book1.author = "George Orwell", book2.title = "To Kill a Mockingbird", book2.author = "Harper Lee".

C++

#include 
#include 

using namespace std;

// Create class Book with public members title and author

int main() {

    // Create book1 and book2 with given titles and authors

    return 0;
}

Need a hint?

Define the Book class with two public string variables. Then create two Book objects and assign the exact titles and authors.

2

Create the Library class with a vector of books

Add a class called Library with a public vector<Book> member named books. Include #include <vector> at the top. In main(), create a Library object named library.

C++

#include 
#include 
#include 

using namespace std;

class Book {
public:
    string title;
    string author;
};

// Create class Library with public vector books

int main() {
    Book book1;
    book1.title = "1984";
    book1.author = "George Orwell";

    Book book2;
    book2.title = "To Kill a Mockingbird";
    book2.author = "Harper Lee";

    // Create Library object named library

    return 0;
}

Need a hint?

Include the vector header. Define Library with a public vector of Book. Then create a Library object in main().

3

Add addBook method to Library

Add a public method addBook to the Library class that takes a Book parameter named book and adds it to the books vector using push_back. In main(), call library.addBook(book1) and library.addBook(book2).

C++

#include 
#include 
#include 

using namespace std;

class Book {
public:
    string title;
    string author;
};

class Library {
public:
    vector books;

    // Add addBook method here
};

int main() {
    Book book1;
    book1.title = "1984";
    book1.author = "George Orwell";

    Book book2;
    book2.title = "To Kill a Mockingbird";
    book2.author = "Harper Lee";

    Library library;

    // Add books to library here

    return 0;
}

Need a hint?

Define addBook inside Library to add a Book to the books vector. Then call it twice in main().

4

Add printBooks method and print all books

Add a public method printBooks to Library that uses a for loop with variables book to iterate over books and prints each book's title and author in the format: Title: [title], Author: [author]. In main(), call library.printBooks().

C++

#include 
#include 
#include 

using namespace std;

class Book {
public:
    string title;
    string author;
};

class Library {
public:
    vector books;

    void addBook(Book book) {
        books.push_back(book);
    }

    // Add printBooks method here
};

int main() {
    Book book1;
    book1.title = "1984";
    book1.author = "George Orwell";

    Book book2;
    book2.title = "To Kill a Mockingbird";
    book2.author = "Harper Lee";

    Library library;

    library.addBook(book1);
    library.addBook(book2);

    // Call printBooks here

    return 0;
}

Need a hint?

Use a for loop to go through each Book in books and print the title and author. Then call printBooks() in main().