Summary  
This chapter covers constructor delegation: using one constructor to call another within the same class to centralize and reuse initialization code.

General domain of usage  
Object-oriented programming

#define CATCH_CONFIG_MAIN
#include <catch2/catch.hpp>
#include <string>

class Book {
public:
    Book(const std::string& bookTitle, const std::string& bookAuthor, int publicationYear)
        : title(bookTitle), author(bookAuthor), year(publicationYear) {}

    Book(const std::string& bookTitle, const std::string& bookAuthor)
        : Book(bookTitle, bookAuthor, 0) {}

    Book(const std::string& bookTitle)
        : Book(bookTitle, "Unknown", 0) {}

    std::string title;
    std::string author;
    int year;
};

// ------------------- Tests -------------------

TEST_CASE("Book with full info should store title, author, and year", "[Book]") {
    Book book("1984", "George Orwell", 1949);

    REQUIRE(book.title == "1984");
    REQUIRE(book.author == "George Orwell");
    REQUIRE(book.year == 1949);
}

TEST_CASE("Book without year should default year to 0", "[Book]") {
    Book book("Clean Code", "Robert C. Martin");

    REQUIRE(book.title == "Clean Code");
    REQUIRE(book.author == "Robert C. Martin");
    REQUIRE(book.year == 0);
}

TEST_CASE("Book with only title should default author to Unknown and year to 0", "[Book]") {
    Book book("Mystery Book");

    REQUIRE(book.title == "Mystery Book");
    REQUIRE(book.author == "Unknown");
    REQUIRE(book.year == 0);
}

test.cpp

Object-Oriented Programming (OOP) in C++ helps you build clean, reusable, and scalable code by organizing programs around objects and classes. You'll learn how to define and use classes, as well as how constructors and destructors help you design flexible and efficient code structures.

Learn how to create classes and objects, define attributes and methods, work with static members and the this keyword. Gain a solid foundation in how objects interact and how to write clean, modular code using OOP principles.

Challenge: Constructor Delegation

Example

Solution