C++ Enumeration

In C++, an enumeration (enum) is a user-defined data type that consists of integral constants. Enumerations provide a way to define a set of named constants, which can make your code more readable and maintainable.

1. Declaring and Using Enumerations

Example of declaring and using an enumeration:

#include <iostream>

// Define an enumeration
enum Weekday {
    Monday,
    Tuesday,
    Wednesday,
    Thursday,
    Friday,
    Saturday,
    Sunday
};

int main() {
    // Declare a variable of type Weekday
    Weekday today = Wednesday;

    // Output the value of today
    std::cout << "Today is ";

    // Switch statement to check the value of today
    switch (today) {
        case Monday:
            std::cout << "Monday";
            break;
        case Tuesday:
            std::cout << "Tuesday";
            break;
        case Wednesday:
            std::cout << "Wednesday";
            break;
        case Thursday:
            std::cout << "Thursday";
            break;
        case Friday:
            std::cout << "Friday";
            break;
        case Saturday:
            std::cout << "Saturday";
            break;
        case Sunday:
            std::cout << "Sunday";
            break;
        default:
            std::cout << "Unknown day";
            break;
    }

    std::cout << std::endl;

    return 0;
}

2. Assigning Values to Enumerators

You can explicitly assign values to enumerators:

#include <iostream>

// Define an enumeration with explicit values
enum Color {
    Red = 1,
    Green = 2,
    Blue = 4
};

int main() {
    // Declare a variable of type Color
    Color selectedColor = Blue;

    // Output the value of selectedColor
    std::cout << "Selected color: ";

    // Switch statement to check the value of selectedColor
    switch (selectedColor) {
        case Red:
            std::cout << "Red";
            break;
        case Green:
            std::cout << "Green";
            break;
        case Blue:
            std::cout << "Blue";
            break;
        default:
            std::cout << "Unknown color";
            break;
    }

    std::cout << std::endl;

    return 0;
}

Conclusion

Enumerations in C++ provide a way to define a set of named constants, improving code readability and maintainability by assigning meaningful names to integral values. This chapter covered basic enumeration declaration, assigning values to enumerators, and using enumerations in switch statements. Understanding enumerations allows you to create more expressive and organized code in your C++ programs.