C++ Structures

In C++, a structure is a user-defined data type that allows you to group together variables of different data types under a single name. Structures provide a way to organize related data and are often used to represent records or entities in a program.

Example:

#include <iostream>
#include <string>

// Define a structure named "Person"
struct Person {
    // Member variables (data members)
    std::string name;
    int age;
    double height;
};

int main() {
    // Declare a variable of type "Person"
    Person person1;

    // Access and modify the member variables
    person1.name = "John";
    person1.age = 25;
    person1.height = 1.75;

    // Display information
    std::cout << "Name: " << person1.name << std::endl;
    std::cout << "Age: " << person1.age << std::endl;
    std::cout << "Height: " << person1.height << " meters" << std::endl;

    return 0;
}

In this example, we define a structure named Person with three member variables: name, age, and height. We then declare a variable of type Person named person1 and use it to store information about an individual.

Initialization of Structure:

Person person2 = {"Alice", 30, 1.65};

Nested Structures:

// Define a nested structure
struct Address {
    std::string street;
    std::string city;
    std::string country;
};

// Define a structure with a nested structure
struct Employee {
    std::string name;
    int age;
    Address address; // Nested structure
};

int main() {
    // Declare and initialize an employee
    Employee employee1 = {"Bob", 28, {"123 Main St", "Cityville", "Countryland"}};

    // Access and display information
    std::cout << "Name: " << employee1.name << std::endl;
    std::cout << "Age: " << employee1.age << std::endl;
    std::cout << "Address: " << employee1.address.street << ", " << employee1.address.city << ", "
              << employee1.address.country << std::endl;

    return 0;
}

Array of Structures:

// Define a structure for a book
struct Book {
    std::string title;
    std::string author;
    int year;
};

int main() {
    // Declare an array of books
    Book library[3];

    // Initialize the array elements
    library[0] = {"The Catcher in the Rye", "J.D. Salinger", 1951};
    library[1] = {"To Kill a Mockingbird", "Harper Lee", 1960};
    library[2] = {"1984", "George Orwell", 1949};

    // Display information about each book
    for (int i = 0; i < 3; ++i) {
        std::cout << "Title: " << library[i].title << std::endl;
        std::cout << "Author: " << library[i].author << std::endl;
        std::cout << "Year: " << library[i].year << std::endl;
        std::cout << std::endl;
    }

    return 0;
}

Structures provide a way to organize and encapsulate related data, improving the clarity and maintainability of your code. They are a fundamental building block in C++ programming.