这两个枚举声明有什么区别？ [英] What's the difference between these two enum declarations - C?

问题描述

我开始学习C，并达到了枚举的程度。一个枚举基本上是替代 DEFINE / const int ，正确吗？

这两个声明有什么区别？

  #include< stdio.h> 
 
 //方法1 
枚举日{
星期一，
星期二
}; 
 
 int main（）
 {
 //方法1 
今天的日子; 
明天明天; 
 
 today = Monday; 
明天=星期二; 
 
 if（today< tomorrow）
 printf（yes\\\
）; 
 
 //方法2 
枚举{星期一，星期二}天; 
 
 days = Tuesday; 
 printf（％d\\\
，days）; 
 
 return 0; 
} 
  

解决方案

枚举应优先于当您想要声明只能从有限范围的 c 相关，相互排斥的值。所以这个星期的日子是一个好的例子，但这将是一个恶劣的例子。

 枚举AboutMe 
 {
 myAge = 27，
 myNumberOfLegs = 2，
 myHouseNumber = 54 
}; 
  

回到你的代码示例;第一种方法声明一个名为 enum days 的类型。您可以使用此类型声明任意多的变量。

第二种方法声明单个变量 >枚举{...} 。您不能声明该类型的任何其他变量。

I've started learning C and have reached the point of enums. An enum is basically a preferred alternative to DEFINE / const int, correct?

What's the difference between these two declarations?

#include <stdio.h>

// method 1
enum days {
    Monday,
    Tuesday
};

int main()
{
    // method 1
    enum days today;
    enum days tomorrow;

    today    = Monday;
    tomorrow = Tuesday;

    if (today < tomorrow)
        printf("yes\n");

    // method 2
    enum {Monday, Tuesday} days;

    days = Tuesday;
    printf("%d\n", days);

    return 0;
}

解决方案

An enumeration should be preferred over #define/const int when you want to declare variables that can only take on values out of a limited range of related, mutually exclusive values. So the days of the week is a good example, but this would be a bad example:

enum AboutMe
{
    myAge = 27,
    myNumberOfLegs = 2,
    myHouseNumber = 54
};

Going back to your code example; the first method declares a type called enum days. You can use this type to declare as many variables as you like.

The second method declares a single variable of type enum { ... }. You cannot declare any other variables of that type.

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