C++ - 介绍enum的使用

在 C++ 中，枚举关键字用于定义枚举，枚举是一种用户定义的数据类型，由一组命名的积分常量组成。枚举可以用有意义的名称来表示相关常量的集合，从而提高代码的可读性和可维护性。

In C++, the enum keyword is used to define an enumeration, which is a user-defined data type consisting of a set of named integral constants. Enumerations are useful for representing a collection of related constants with meaningful names, improving code readability and maintainability.

Basic Enum Definition

Here’s how you can define and use a basic enumeration in C++:

#include <iostream>

// Define an enum outside of any class

enum Color {

    RED,

    GREEN,

    BLUE

};

int main() {

    // Declare a variable of type Color

    Color myColor = RED;

    // Use the enum variable in a switch statement

    switch (myColor) {

        case RED:

            std::cout << "The color is RED" << std::endl;

            break;

        case GREEN:

            std::cout << "The color is GREEN" << std::endl;

            break;

        case BLUE:

            std::cout << "The color is BLUE" << std::endl;

            break;

        default:

            std::cout << "Unknown color" << std::endl;

            break;

    }

    return 0;

}

Scoped Enumerations (enum class)

在 C++11 及更高版本中，可以使用 enum class（或 enum struct）定义作用域枚举。作用域枚举提供了更好的类型安全性，并防止了全局命名空间的污染。

In C++11 and later, you can define scoped enumerations using enum class (or enum struct). Scoped enumerations provide better type safety and prevent pollution of the global namespace.

#include <iostream>

// Define a scoped enum (enum class)

enum class Color {

    RED,

    GREEN,

    BLUE

};

int main() {

    // Declare a variable of type Color

    Color myColor = Color::RED;

    // Use the enum variable in a switch statement

    switch (myColor) {

        case Color::RED:

            std::c