Parameterized constructor in C++ - Mini Project: Build & Apply

Parameterized constructor

📖 Scenario: Imagine you are creating a simple program to store information about books in a library. Each book has a title and a number of pages.

🎯 Goal: You will create a class called Book with a parameterized constructor to set the title and number of pages when creating a new book object.

📋 What You'll Learn

Create a class named Book

Add a parameterized constructor to Book that takes title and pages

Store the title and pages in member variables

Create a printDetails method to display the book's title and pages

Create a Book object with title "C++ Basics" and pages 250

Call printDetails to show the book information

💡 Why This Matters

🌍 Real World

Classes with parameterized constructors are used to create objects with specific initial data, like books in a library system.

💼 Career

Understanding constructors is essential for object-oriented programming jobs, enabling you to build flexible and reusable code.

1

Create the Book class with member variables

Create a class called Book with two private member variables: title of type std::string and pages of type int.

C++

// Your code here

Need a hint?

Use class Book { private: std::string title; int pages; }; to define the class and variables.

2

Add a parameterized constructor to Book

Add a public parameterized constructor to the Book class that takes std::string title and int pages as parameters and sets the member variables accordingly.

C++

#include 
#include 

class Book {
private:
    std::string title;
    int pages;
public:
    // Add a parameterized constructor here
    // Your code here
};

int main() {
    return 0;
}

Need a hint?

Use Book(std::string title, int pages) { this->title = title; this->pages = pages; } inside the class.

3

Add a method to print book details

Add a public method called printDetails to the Book class that prints the book's title and number of pages in the format: Title: [title], Pages: [pages].

C++

#include 
#include 

class Book {
private:
    std::string title;
    int pages;
public:
    Book(std::string title, int pages) {
        this->title = title;
        this->pages = pages;
    }
    // Add printDetails method here
    // Your code here
};

int main() {
    return 0;
}

Need a hint?

Define void printDetails() { std::cout << "Title: " << title << ", Pages: " << pages << std::endl; }.

4

Create a Book object and print details

In main(), create a Book object named myBook using the parameterized constructor with title "C++ Basics" and pages 250. Then call myBook.printDetails() to display the book information.

C++

#include 
#include 

class Book {
private:
    std::string title;
    int pages;
public:
    Book(std::string title, int pages) {
        this->title = title;
        this->pages = pages;
    }
    void printDetails() {
        std::cout << "Title: " << title << ", Pages: " << pages << std::endl;
    }
};

int main() {
    // Create myBook object and call printDetails
    // Your code here
    return 0;
}

Need a hint?

Create the object with Book myBook("C++ Basics", 250); and call myBook.printDetails();.