📌 Structure & Functions Examples in C++

Structures in C++ allow us to group related data together. We can also use functions to operate on structures.

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1️⃣ Area of Rectangle using Structure & Function

📌 Using a function to calculate and return the area of a rectangle.

#include <iostream>
using namespace std;

struct Rectangle {
    double length, width;
};

double calculateArea(Rectangle r) {
    return r.length * r.width;
}

int main() {
    Rectangle rect;
    cout << "Enter Length and Width: ";
    cin >> rect.length >> rect.width;

    cout << "Area of Rectangle: " << calculateArea(rect) << endl;
    return 0;
}

🔹 Output

Enter Length and Width: 5 10
Area of Rectangle: 50

📌 Key Points:
✔ Function calculateArea() receives a structure object as a parameter.
✔ The function returns the area after calculation.

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2️⃣ Show Book Information using Structure & Function

📌 Using a function to display book details.

#include <iostream>
using namespace std;

struct Book {
    string title;
    string author;
    double price;
};

void displayBook(Book b) {
    cout << "\nBook Details:\n";
    cout << "Title: " << b.title << "\nAuthor: " << b.author << "\nPrice: $" << b.price << endl;
}

int main() {
    Book book;
    cout << "Enter Book Title: ";
    getline(cin, book.title);
    cout << "Enter Author: ";
    getline(cin, book.author);
    cout << "Enter Price: ";
    cin >> book.price;

    displayBook(book);
    return 0;
}

🔹 Output

Enter Book Title: C++ Basics
Enter Author: John Smith
Enter Price: 29.99

Book Details:
Title: C++ Basics
Author: John Smith
Price: $29.99

📌 Key Points:
✔ displayBook() function takes a structure as an argument.
✔ Pass-by-value is used to avoid modifying the original structure.

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3️⃣ Show Person Information using Structure & Function

📌 Using a function to display person details.

#include <iostream>
using namespace std;

struct Person {
    string name;
    int age;
    string city;
};

void displayPerson(const Person &p) {
    cout << "\nPerson Details:\n";
    cout << "Name: " << p.name << "\nAge: " << p.age << "\nCity: " << p.city << endl;
}

int main() {
    Person person;
    cout << "Enter Name: ";
    getline(cin, person.name);
    cout << "Enter Age: ";
    cin >> person.age;
    cin.ignore();
    cout << "Enter City: ";
    getline(cin, person.city);

    displayPerson(person);
    return 0;
}

🔹 Output

Enter Name: Alice Johnson
Enter Age: 25
Enter City: New York

Person Details:
Name: Alice Johnson
Age: 25
City: New York

📌 Key Points:
✔ displayPerson() function takes a constant reference (const Person &p) to prevent modifications and improve efficiency.
✔ cin.ignore() is used to clear the buffer before getline().

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📌 Summary

✔ Functions can take structures as parameters.
✔ Use pass-by-value when you don't want changes in the original structure.
✔ Use pass-by-reference (const &) for efficiency.
✔ Functions improve code reusability and modularity.

🚀 Need more examples? Let me know! 🔥