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Enumerations (Enums) in C++

An enumeration (enum) is a user-defined data type consisting of integral constants assigned with names. Enums make code more readable and maintainable by replacing numeric constants with meaningful names.

Defining an Enum

Syntax

enum EnumName {
    CONSTANT1,
    CONSTANT2,
    // ...
};

Example: Defining and Using an Enum

#include <iostream>

enum Direction {
    NORTH,
    EAST,
    SOUTH,
    WEST
};

int main() {
    Direction dir = SOUTH;
    if (dir == SOUTH) {
        std::cout << "Heading South" << std::endl;
    }
    return 0;
}

Assigning Specific Values

You can assign specific integer values to enum constants.

Example: Enum with Specific Values

enum Weekday {
    MONDAY = 1,
    TUESDAY,
    WEDNESDAY,
    THURSDAY,
    FRIDAY,
    SATURDAY,
    SUNDAY
};

Key Takeaways

  • Enums associate names with integral constants.
  • Improve code readability by using meaningful names.
  • By default, the first constant is assigned 0, and the rest increment by 1.

Strongly Typed Enums (C++11)

C++11 introduced enum class for better type safety.

Example: Using enum class

enum class Color {
    RED,
    GREEN,
    BLUE
};

int main() {
    Color myColor = Color::GREEN;
    if (myColor == Color::GREEN) {
        std::cout << "Color is Green" << std::endl;
    }
    return 0;
}

Key Takeaways

  • enum class provides scoped and strongly typed enums.
  • Prevents implicit conversions to integers.
  • Access enum constants using the scope resolution operator (::).
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