Here’s a complete and SEO-optimized article on C++ Enums and Enum Class, including examples, differences, use cases, best practices, and FAQ:

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🧾 C++ Enums & enum class – Strongly-Typed Constants in C++

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🧲 Introduction – Why Learn C++ Enums?

In C++ programming, enums (enumerations) are used to define a set of named integral constants that make code more readable and less error-prone. The modern enum class introduced in C++11 further improves type safety, preventing unintended conversions and name conflicts.

🎯 In this guide, you’ll learn:

• What is an enum and enum class
• Syntax and usage examples
• Enum vs enum class comparison
• Use cases in real-world projects
• Best practices and common pitfalls

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🔍 Core Concept – What is an Enum in C++?

An enum defines a group of related constant integer values using identifiers.

enum Color { RED, GREEN, BLUE };

By default:

• RED = 0, GREEN = 1, BLUE = 2
• Enums are of type int unless specified otherwise.

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💻 Code Examples – With Explanation

✅ Example 1: Basic Enum Usage

#include <iostream>
using namespace std;

enum Direction { North, South, East, West };

int main() {
    Direction d = East;
    cout << "Direction: " << d << endl; // Output: 2
    return 0;
}

🔍 Explanation:

• East is the 3rd element (index 2)
• Enums are implicitly convertible to int

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✅ Example 2: Enum with Assigned Values

enum Status {
    OK = 200,
    NOT_FOUND = 404,
    SERVER_ERROR = 500
};

📘 Useful when mapping enums to HTTP status codes or error values.

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✅ Example 3: enum class (Scoped Enum)

#include <iostream>
using namespace std;

enum class State { Idle, Running, Stopped };

int main() {
    State s = State::Running;

    if (s == State::Running) {
        cout << "System is active.\n";
    }

    return 0;
}

🔍 Why Use enum class?

• Scoped ➝ no global name pollution
• Strongly typed ➝ prevents implicit conversion to int

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💡 Best Practices & Tips

📘 Best Practices:

• Use enum class for type safety and clarity
• Specify underlying type (enum class Mode : uint8_t { ... };) for memory control
• Use switch statements with default to catch unhandled enum cases

💡 Tips:

• For readable output, use std::map or std::unordered_map for enum-to-string conversion
• Create utility functions for string mapping if enum values are user-facing

⚠️ Common Pitfalls:

• Using traditional enums causes naming collisions in global scope
• Mixing enums from different domains accidentally (e.g., Color == Direction)
• Forgetting to handle all enum values in switch can lead to bugs

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📊 Enum vs Enum Class – Comparison Table

Feature	enum (Traditional)	enum class (Scoped Enum)
Scope	Global	Local to the enum
Type Safety	❌ Not type-safe	✅ Strongly typed
Implicit Conversion	✅ Converts to int	❌ Requires explicit cast
Duplicate Identifiers	Possible (causes conflicts)	Not allowed (must use scope)
Use Case	Legacy code	Modern, safer C++ code

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🛠️ Use Cases & Industry Applications

📦 Where to Use Enums:

• State machines (e.g., game or device states)
• HTTP status codes
• Day of the week, months
• Error handling and logging levels
• User permissions or roles

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📌 Summary – Recap & Next Steps

C++ enums and enum class help organize and manage fixed sets of constants, enhancing code readability and maintainability.

🔍 Key Takeaways:

• Use traditional enum for backward compatibility
• Prefer enum class for type-safe, scoped enumerations
• Always handle all possible enum values in control statements

⚙️ Next Steps:

• Explore std::variant or std::optional with enums
• Learn how to implement enum-to-string mapping
• Use enums inside classes or namespaces for clean architecture

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❓ FAQ Section

❓ What is the default type of C++ enum?

✅ int is the default underlying type unless explicitly specified.

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❓ Can enum values be printed directly?

✅ Yes, but it prints the underlying integer. Use custom mapping for strings.

cout << Color::RED; // Prints 0

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❓ How to convert enum class to int?

int val = static_cast<int>(State::Running);

✅ You must use static_cast because enum class is strongly typed.

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❓ Can enums be used in switch statements?

✅ Yes, both enum and enum class can be used, but enum class requires static_cast or fully qualified names.

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❓ Can I assign custom values to enum class members?

✅ Yes.

enum class Level : int {
    Low = 1, Medium = 5, High = 10
};

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